libftdi

https://www.intra2net.com/en/developer/libftdi/
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libftdi is a C library for communicating with FTDI USB devices, enabling developers to interface...
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### Basic libftdi Usage Example

Source: https://www.intra2net.com/en/developer/libftdi/documentation/index.html

This example demonstrates the basic usage of libftdi, including initialization, opening a device, reading chip information, closing the device, and freeing resources. It requires the ftdi.h header and links against the libftdi library.

```c
#include <stdio.h>
#include <stdlib.h>
#include <ftdi.h>
int main(void)
{
int ret;
struct ftdi_context *ftdi;
struct ftdi_version_info version;
if ((ftdi = ftdi_new()) == 0)
{
fprintf(stderr, "ftdi_new failed\n");
return EXIT_FAILURE;
}
version = ftdi_get_library_version();
printf("Initialized libftdi %s (major: %d, minor: %d, micro: %d, snapshot ver: %s)\n",
version.version_str, version.major, version.minor, version.micro,
version.snapshot_str);
if ((ret = ftdi_usb_open(ftdi, 0x0403, 0x6001)) < 0)
{
fprintf(stderr, "unable to open ftdi device: %d (%s)\n", ret, ftdi_get_error_string(ftdi));
ftdi_free(ftdi);
return EXIT_FAILURE;
}
// Read out FTDIChip-ID of R type chips
if (ftdi->type == TYPE_R)
{
unsigned int chipid;
printf("ftdi_read_chipid: %d\n", ftdi_read_chipid(ftdi, &chipid));
printf("FTDI chipid: %X\n", chipid);
}
if ((ret = ftdi_usb_close(ftdi)) < 0)
{
fprintf(stderr, "unable to close ftdi device: %d (%s)\n", ret, ftdi_get_error_string(ftdi));
ftdi_free(ftdi);
return EXIT_FAILURE;
}
ftdi_free(ftdi);
return EXIT_SUCCESS;
}

```

--------------------------------

### Example Code for Async Mode in libFTDI

Source: https://www.intra2net.com/en/developer/libftdi

This snippet is an example demonstrating the asynchronous mode of operation within the libFTDI library. It is intended to showcase how to implement non-blocking data transfers.

```c
/* Add example code for async mode */
```

--------------------------------

### Initialize and Start FTDI Stream

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi__stream_8c_source.html

Sets up and initiates a data stream from an FTDI device in synchronous FIFO mode. It configures USB transfers, handles device mode switching, and starts the event loop for data reception. Ensure the device supports synchronous FIFO mode before calling.

```c
int
ftdi_readstream(struct ftdi_context *ftdi,
 FTDIStreamCallback *callback, void *userdata,
 int packetsPerTransfer, int numTransfers)
{
struct libusb_transfer **transfers;
FTDIStreamState state = { callback, userdata, ftdi->max_packet_size, 1 };
int bufferSize = packetsPerTransfer * ftdi->max_packet_size;
int xferIndex;
int err = 0;

/* Only FT2232H and FT232H know about the synchronous FIFO Mode*/
if ((ftdi->type != TYPE_2232H) && (ftdi->type != TYPE_232H))
{
fprintf(stderr,"Device doesn't support synchronous FIFO mode\n");
return 1;
}

/* We don't know in what state we are, switch to reset*/
if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_RESET) < 0)
{
fprintf(stderr,"Can't reset mode\n");
return 1;
}

/* Purge anything remaining in the buffers*/
if (ftdi_tcioflush(ftdi) < 0)
{
fprintf(stderr,"Can't flush FIFOs & buffers\n");
return 1;
}

/*
* Set up all transfers
*/

transfers = calloc(numTransfers, sizeof *transfers);
if (!transfers)
{
err = LIBUSB_ERROR_NO_MEM;
goto cleanup;
}

for (xferIndex = 0; xferIndex < numTransfers; xferIndex++)
{
struct libusb_transfer *transfer;

transfer = libusb_alloc_transfer(0);
transfers[xferIndex] = transfer;
if (!transfer)
{
err = LIBUSB_ERROR_NO_MEM;
goto cleanup;
}

libusb_fill_bulk_transfer(transfer, ftdi->usb_dev, ftdi->out_ep,
malloc(bufferSize), bufferSize,
ftdi_readstream_cb,
&state, 0);

if (!transfer->buffer)
{
err = LIBUSB_ERROR_NO_MEM;
goto cleanup;
}

transfer->status = -1;
err = libusb_submit_transfer(transfer);
if (err)
goto cleanup;
}

/* Start the transfers only when everything has been set up.
* Otherwise the transfers start stuttering and the PC not
* fetching data for several to several ten milliseconds
* and we skip blocks
*/
if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_SYNCFF) < 0)
{
fprintf(stderr,"Can't set synchronous fifo mode: %s\n",
ftdi_get_error_string(ftdi));
goto cleanup;
}

/*
* Run the transfers, and periodically assess progress.
*/

gettimeofday(&state.progress.first.time, NULL);

do
{
FTDIProgressInfo *progress = &state.progress;
const double progressInterval = 1.0;
struct timeval timeout = { 0, ftdi->usb_read_timeout * 1000};
struct timeval now;

int err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
if (err == LIBUSB_ERROR_INTERRUPTED)
/* restart interrupted events */
err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
if (!state.result)
{
state.result = err;
}
if (state.activity == 0)
state.result = 1;
else
state.activity = 0;

// If enough time has elapsed, update the progress
gettimeofday(&now, NULL);
if (TimevalDiff(&now, &progress->current.time) >= progressInterval)
{
progress->current.time = now;
progress->totalTime = TimevalDiff(&progress->current.time,
&progress->first.time);

if (progress->prev.totalBytes)
{
// We have enough information to calculate rates

double currentTime;

currentTime = TimevalDiff(&progress->current.time,
&progress->prev.time);

progress->totalRate =
progress->current.totalBytes /progress->totalTime;
progress->currentRate =
(progress->current.totalBytes -
progress->prev.totalBytes) / currentTime;
}

state.callback(NULL, 0, progress, state.userdata);
progress->prev = progress->current;

}
} while (!state.result);

/*
* Cancel any outstanding transfers, and free memory.
*/

cleanup:
fprintf(stderr, "cleanup\n");
if (transfers)
free(transfers);
if (err)
return err;
else
return state.result;
}

```

--------------------------------

### Ftdi::Context::description()

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Gets the description string of the FTDI device.

```APIDOC
const std::string & Ftdi::Context::description();
```

--------------------------------

### Basic libftdi Usage Example

Source: https://www.intra2net.com/en/developer/libftdi/documentation

This C code demonstrates the fundamental steps of initializing libftdi, opening an FTDI device by vendor and product ID, reading the chip ID for 'R' type chips, and then closing the device. Ensure you have the necessary headers and link against the libftdi library.

```c
#include <stdio.h>
#include <stdlib.h>
#include <ftdi.h>
int main(void)
{
int ret;
struct ftdi_context *ftdi;
struct ftdi_version_info version;
if ((ftdi = ftdi_new()) == 0)
{
fprintf(stderr, "ftdi_new failed\n");
return EXIT_FAILURE;
}
version = ftdi_get_library_version();
printf("Initialized libftdi %s (major: %d, minor: %d, micro: %d, snapshot ver: %s)\n",
version.version_str, version.major, version.minor, version.micro,
version.snapshot_str);
if ((ret = ftdi_usb_open(ftdi, 0x0403, 0x6001)) < 0)
{
fprintf(stderr, "unable to open ftdi device: %d (%s)\n", ret, ftdi_get_error_string(ftdi));
ftdi_free(ftdi);
return EXIT_FAILURE;
}
// Read out FTDIChip-ID of R type chips
if (ftdi->type == TYPE_R)
{
unsigned int chipid;
printf("ftdi_read_chipid: %d\n", ftdi_read_chipid(ftdi, &chipid));
printf("FTDI chipid: %X\n", chipid);
}
if ((ret = ftdi_usb_close(ftdi)) < 0)
{
fprintf(stderr, "unable to close ftdi device: %d (%s)\n", ret, ftdi_get_error_string(ftdi));
ftdi_free(ftdi);
return EXIT_FAILURE;
}
ftdi_free(ftdi);
return EXIT_SUCCESS;
}
```

--------------------------------

### Get Description String

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Returns the description string for the FTDI device. If not already retrieved, it calls get_strings_and_reopen to fetch it.

```cpp
const std::string& Context::description()
{
  if(d->description.empty())
  get_strings_and_reopen(false,true,false);
  return d->description;
}
```

--------------------------------

### Loopback Definitions

Source: https://www.intra2net.com/en/developer/libftdi/documentation/globals_l.html

These macros define the start and end points for loopback operations within the libftdi library.

```APIDOC
## Macros

### LOOPBACK_END

* **Description**: Defines the end of the loopback sequence.
* **File**: ftdi.h

### LOOPBACK_START

* **Description**: Defines the start of the loopback sequence.
* **File**: ftdi.h
```

--------------------------------

### Get List Size

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Returns the number of FTDI contexts currently in the list. This indicates how many devices were found.

```cpp
List::ListType::size_type List::size() const
{
  return d->list.size();
}
```

--------------------------------

### Get Vendor String

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Returns the vendor string for the FTDI device. If not already retrieved, it calls get_strings_and_reopen to fetch it.

```cpp
const std::string& Context::vendor()
{
  if(d->vendor.empty())
  get_strings_and_reopen(true,false,false);
  return d->vendor;
}
```

--------------------------------

### Get FTDI Device Strings

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Retrieves vendor, description, and serial strings for the FTDI device. Buffers are prepared internally. Ensure sufficient buffer sizes are allocated.

```cpp
int Context::get_strings(bool vendor, bool description, bool serial)
{
  // Prepare buffers
  char ivendor[512], idesc[512], iserial[512];

  int ret = ftdi_usb_get_strings(d->ftdi, d->dev, vendor?ivendor:NULL, 512, description?idesc:NULL, 512, serial?iserial:NULL, 512);

  if (ret < 0)
  return -1;

  d->vendor = ivendor;
  d->description = idesc;
  d->serial = iserial;

  return 1;
}
```

--------------------------------

### Get FTDI Device Strings

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Retrieves vendor, description, and serial number strings from the FTDI device. Specify which strings to retrieve.

```cpp
int Ftdi::Context::get_strings(bool vendor=true, bool description=true, bool serial=true)
{
return get_strings(vendor, description, serial);
}
```

--------------------------------

### Get Strings and Reopen Device

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Retrieves device strings and reopens the FTDI device. This is necessary after getting strings, as the operation can close the device.

```cpp
int Context::get_strings_and_reopen(bool vendor, bool description, bool serial)
{
  int ret = 0;

  if(vendor || description || serial)
  {
    if (d->dev == 0)
    {
      d->dev = libusb_get_device(d->ftdi->usb_dev);
    }

    // Get device strings (closes device)
    ret=get_strings(vendor, description, serial);
    if (ret < 0)
    {
      d->open = 0;
      return ret;
    }

    // Reattach device
    ret = ftdi_usb_open_dev(d->ftdi, d->dev);
    d->open = (ret >= 0);
  }

  return ret;
}
```

--------------------------------

### CBUS Python Example Code

Source: https://www.intra2net.com/en/developer/libftdi

This snippet refers to the inclusion of example code for utilizing the CBUS (Common Bus) functionality with Python wrappers for libFTDI.

```python
/* cbus python example code (Rodney Sinclair) */
```

--------------------------------

### Import GPG Key

Source: https://www.intra2net.com/en/developer/libftdi/download.php

Import the GPG public key for verifying signatures. Ensure the key file is downloaded first.

```bash
gpg --import opensource-intra2net.asc
```

--------------------------------

### Context::open(int vendor, int product, const std::string& description, const std::string& serial, unsigned int index)

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Opens an FTDI device using vendor ID, product ID, and optional description, serial number, and index. This allows for more specific device selection.

```APIDOC
## Context::open(int vendor, int product, const std::string& description, const std::string& serial, unsigned int index)

### Description
Opens an FTDI device using vendor ID, product ID, and optional description, serial number, and index. This allows for more specific device selection.

### Method
```cpp
int Context::open(int vendor, int product, const std::string& description, const std::string& serial, unsigned int index)
```

### Parameters
* **vendor** (int) - The vendor ID of the FTDI device.
* **product** (int) - The product ID of the FTDI device.
* **description** (const std::string&) - An optional description string for device matching.
* **serial** (const std::string&) - An optional serial number string for device matching.
* **index** (unsigned int) - The index of the device to open if multiple devices match the criteria.

### Returns
Returns 0 on success, or a negative error code on failure.
```

--------------------------------

### Ftdi::Context Class Members - Functions starting with 'g'

Source: https://www.intra2net.com/en/developer/libftdi/documentation/functions_g.html

This section lists functions within the Ftdi::Context class whose names start with the letter 'g'. These functions are related to retrieving information about the FTDI device, such as strings and USB timeouts.

```APIDOC
## get_strings()

### Description
Retrieves strings associated with the FTDI context.

### Method
(Not specified, likely a C function call)

### Endpoint
N/A

### Parameters
None explicitly mentioned.

### Request Example
N/A

### Response
- strings (array of strings) - Description not specified.

### Response Example
N/A
```

```APIDOC
## get_strings_and_reopen()

### Description
Retrieves strings and reopens the FTDI context.

### Method
(Not specified, likely a C function call)

### Endpoint
N/A

### Parameters
None explicitly mentioned.

### Request Example
N/A

### Response
- strings (array of strings) - Description not specified.

### Response Example
N/A
```

```APIDOC
## get_usb_read_timeout()

### Description
Retrieves the USB read timeout value for the FTDI context.

### Method
(Not specified, likely a C function call)

### Endpoint
N/A

### Parameters
None explicitly mentioned.

### Request Example
N/A

### Response
- timeout (integer) - The USB read timeout value. Description not specified.

### Response Example
N/A
```

```APIDOC
## get_usb_write_timeout()

### Description
Retrieves the USB write timeout value for the FTDI context.

### Method
(Not specified, likely a C function call)

### Endpoint
N/A

### Parameters
None explicitly mentioned.

### Request Example
N/A

### Response
- timeout (integer) - The USB write timeout value. Description not specified.

### Response Example
N/A
```

--------------------------------

### init_defaults

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Eeprom.html

Initializes EEPROM with default values for manufacturer, product, and serial number.

```APIDOC
## init_defaults()

### Description
Initializes the EEPROM with default values for the manufacturer, product, and serial number.

### Parameters
- **manufacturer** (char *) - The manufacturer string.
- **product** (char *) - The product string.
- **serial** (char *) - The serial number string.

### Returns
An integer status code. 0 on success, negative on error.
```

--------------------------------

### Error String Function

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8h_source.html

Function to get the last error string.

```APIDOC
## ftdi_get_error_string

### Description
Returns a string describing the last error that occurred.

### Signature
```c
const char *ftdi_get_error_string(struct ftdi_context *ftdi);
```
```

--------------------------------

### Context::open(int vendor, int product)

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Opens an FTDI device using its vendor and product IDs. This is a basic method to establish a connection.

```APIDOC
## Context::open(int vendor, int product)

### Description
Opens an FTDI device using its vendor and product IDs. This is a basic method to establish a connection.

### Method
```cpp
int Context::open(int vendor, int product)
```

### Parameters
* **vendor** (int) - The vendor ID of the FTDI device.
* **product** (int) - The product ID of the FTDI device.

### Returns
Returns 0 on success, or a negative error code on failure.
```

--------------------------------

### Context::open

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Opens the FTDI device context. It takes a libusb_device pointer and initializes the internal device structure.

```APIDOC
## Context::open

### Description
Opens the FTDI device context by associating it with a given libusb_device.

### Method
`int open(struct libusb_device *dev)`

### Parameters
* **dev** (`struct libusb_device *`) - A pointer to the libusb_device to be opened.

### Return Value
Returns 0 on success, or -1 if the device is null or an error occurs.
```

--------------------------------

### Ftdi::Context::get_usb_write_timeout

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Gets the USB write timeout value.

```APIDOC
## get_usb_write_timeout

### Description
Gets the USB write timeout value.

### Method
int

### Endpoint
N/A (C++ function)

### Parameters
None

### Request Example
N/A

### Response
#### Success Response (int)
Returns the current USB write timeout value.

#### Response Example
```
1000
```
```

--------------------------------

### Ftdi::Context::open() [2/4]

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Opens the FTDI device using vendor and product IDs.

```APIDOC
int Ftdi::Context::open(int _vendor_, int _product_);
```

--------------------------------

### Ftdi::Context::get_usb_read_timeout

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Gets the USB read timeout value.

```APIDOC
## get_usb_read_timeout

### Description
Gets the USB read timeout value.

### Method
int

### Endpoint
N/A (C++ function)

### Parameters
None

### Request Example
N/A

### Response
#### Success Response (int)
Returns the current USB read timeout value.

#### Response Example
```
1000
```
```

--------------------------------

### Latency Timer

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Get or set the latency timer for the FTDI device.

```APIDOC
## set_latency()

### Description
Sets the latency timer for the FTDI device.

### Method
`int Ftdi::Context::set_latency(unsigned char _latency)`

### Parameters
*   `_latency` (unsigned char) - The desired latency timer value in milliseconds.

### Returns
On success, 0. On error, a negative value.
```

```APIDOC
## latency()

### Description
Retrieves the current latency timer value.

### Method
`unsigned Ftdi::Context::latency()`

### Parameters
None

### Returns
An unsigned integer representing the current latency timer value in milliseconds.
```

--------------------------------

### Ftdi::Context::open() [3/4]

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Opens the FTDI device using vendor ID, product ID, description, serial number, and index.

```APIDOC
int Ftdi::Context::open(int _vendor_, int _product_, const std::string & _description_, const std::string & _serial_ = std::string(), unsigned int _index_ = 0);
```

--------------------------------

### Ftdi::Context::vendor

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Gets the vendor string of the FTDI device.

```APIDOC
## Ftdi::Context::vendor

### Description
Gets the vendor string of the FTDI device.

### Method
const std::string & vendor()

### Parameters
None

### Return Value
Returns a constant reference to the vendor string.
```

--------------------------------

### Initialize EEPROM Defaults

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Initializes the EEPROM structure with default values for manufacturer, product, and serial number. This prepares the EEPROM for writing.

```cpp
int Eeprom::init_defaults(char* manufacturer, char *product, char * serial)
{
  return ftdi_eeprom_initdefaults(d->context, manufacturer, product, serial);
}
```

--------------------------------

### EEPROM Initialization Functions

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8h_source.html

Functions for initializing and building the EEPROM content.

```APIDOC
## ftdi_eeprom_initdefaults

### Description
Initializes EEPROM with default values for manufacturer, product, and serial.

### Signature
```c
int ftdi_eeprom_initdefaults(struct ftdi_context *ftdi,
char * manufacturer, char *product,
char * serial);
```

## ftdi_eeprom_build

### Description
Builds the EEPROM content based on the current settings.

### Signature
```c
int ftdi_eeprom_build(struct ftdi_context *ftdi);
```

## ftdi_eeprom_decode

### Description
Decodes the EEPROM content. If verbose is non-zero, it prints the decoded content.

### Signature
```c
int ftdi_eeprom_decode(struct ftdi_context *ftdi, int verbose);
```
```

--------------------------------

### Ftdi::Context::open() [4/4]

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Opens the FTDI device using a description string.

```APIDOC
int Ftdi::Context::open(const std::string & _description_);
```

--------------------------------

### Ftdi::Context::vendor()

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Gets the vendor string of the FTDI device.

```APIDOC
const std::string & Ftdi::Context::vendor();
```

--------------------------------

### ftdi_eeprom_initdefaults

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8c_source.html

Initializes the EEPROM with default values.

```APIDOC
## ftdi_eeprom_initdefaults

### Description
Initializes the EEPROM with default values.

### Signature
```c
int ftdi_eeprom_initdefaults(struct ftdi_context *ftdi, char *manufacturer, char *product, char *serial)
```

### Parameters
- **ftdi** (*struct ftdi_context*)
- **manufacturer** (char *) - The manufacturer string.
- **product** (char *) - The product string.
- **serial** (char *) - The serial number string.

### Return Value
Returns 0 on success, or a negative error code on failure.
```

--------------------------------

### Create and initialize a new ftdi_context

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8c_source.html

Allocates memory for a new ftdi_context and initializes it by calling ftdi_init. Returns NULL if memory allocation fails or if ftdi_init returns an error.

```c
struct ftdi_context *ftdi_new(void)
{
struct ftdi_context * ftdi = (struct ftdi_context *)malloc(sizeof(struct ftdi_context));

if (ftdi == NULL)
{
return NULL;
}

if (ftdi_init(ftdi) != 0)
{

```

--------------------------------

### Ftdi::Context::write_chunk_size

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Gets the current chunk size for write operations.

```APIDOC
## int write_chunk_size()

### Description
Retrieves the current size of data chunks used for write operations.

### Signature
int write_chunk_size()

### Returns
The current chunk size in bytes.
```

--------------------------------

### Ftdi::List::begin

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Returns an iterator to the beginning of the device list.

```APIDOC
## Ftdi::List::begin

### Description
Returns an iterator to the beginning of the device list.

### Method
iterator begin()

### Parameters
None

### Return Value
Returns an iterator pointing to the first element in the list.
```

--------------------------------

### Ftdi::Context::read_chunk_size

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Gets the current chunk size for read operations.

```APIDOC
## int read_chunk_size()

### Description
Retrieves the current size of data chunks used for read operations.

### Signature
int read_chunk_size()

### Returns
The current chunk size in bytes.
```

--------------------------------

### Latency Timer Functions

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8h_source.html

Functions for setting and getting the latency timer value.

```APIDOC
## ftdi_set_latency_timer

### Description
Sets the latency timer for the FTDI device.

### Signature
```c
int ftdi_set_latency_timer(struct ftdi_context *ftdi, unsigned char latency);
```

## ftdi_get_latency_timer

### Description
Gets the current latency timer value of the FTDI device.

### Signature
```c
int ftdi_get_latency_timer(struct ftdi_context *ftdi, unsigned char *latency);
```
```

--------------------------------

### Error String

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Get a human-readable string describing the last FTDI error.

```APIDOC
## error_string()

### Description
Returns a string describing the last error that occurred.

### Method
`const char * Ftdi::Context::error_string()`

### Parameters
None

### Returns
A pointer to a null-terminated string describing the last error. Returns `NULL` if no error has occurred.
```

--------------------------------

### List Class Methods

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Methods for listing and iterating over available FTDI devices.

```APIDOC
## List Constructor

### Description
Constructs a List object from a `ftdi_device_list`.

### Method
`List(struct ftdi_device_list* devlist)`

### Parameters
- **devlist** (struct ftdi_device_list*) - A pointer to the list of FTDI devices.

### Returns
None
```

```APIDOC
## begin

### Description
Returns an iterator to the beginning of the device list.

### Method
`iterator begin()`

### Parameters
None

### Returns
An iterator to the beginning of the list.
```

```APIDOC
## end

### Description
Returns an iterator to the end of the device list.

### Method
`iterator end()`

### Parameters
None

### Returns
An iterator to the end of the list.
```

```APIDOC
## begin (const)

### Description
Returns a const iterator to the beginning of the device list.

### Method
`const_iterator begin() const`

### Parameters
None

### Returns
A const iterator to the beginning of the list.
```

```APIDOC
## end (const)

### Description
Returns a const iterator to the end of the device list.

### Method
`const_iterator end() const`

### Parameters
None

### Returns
A const iterator to the end of the list.
```

```APIDOC
## rbegin

### Description
Returns a reverse iterator to the beginning of the reversed device list.

### Method
`reverse_iterator rbegin()`

### Parameters
None

### Returns
A reverse iterator to the beginning of the reversed list.
```

```APIDOC
## rend

### Description
Returns a reverse iterator to the end of the reversed device list.

### Method
`reverse_iterator rend()`

### Parameters
None

### Returns
A reverse iterator to the end of the reversed list.
```

```APIDOC
## rbegin (const)

### Description
Returns a const reverse iterator to the beginning of the reversed device list.

### Method
`const_reverse_iterator rbegin() const`

### Parameters
None

### Returns
A const reverse iterator to the beginning of the reversed list.
```

```APIDOC
## rend (const)

### Description
Returns a const reverse iterator to the end of the reversed device list.

### Method
`const_reverse_iterator rend() const`

### Parameters
None

### Returns
A const reverse iterator to the end of the reversed list.
```

```APIDOC
## size

### Description
Returns the number of devices in the list.

### Method
`ListType::size_type size() const`

### Parameters
None

### Returns
The number of devices.
```

```APIDOC
## empty

### Description
Checks if the device list is empty.

### Method
`bool empty() const`

### Parameters
None

### Returns
`true` if the list is empty, `false` otherwise.
```

```APIDOC
## clear

### Description
Clears the device list and frees associated resources.

### Method
`void clear()`

### Parameters
None

### Returns
None
```

--------------------------------

### Ftdi::Context::serial

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Gets the serial number string of the FTDI device.

```APIDOC
## Ftdi::Context::serial

### Description
Gets the serial number string of the FTDI device.

### Method
const std::string & serial()

### Parameters
None

### Return Value
Returns a constant reference to the serial number string.
```

--------------------------------

### Ftdi::Eeprom::init_defaults

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Initializes the EEPROM with default values.

```APIDOC
## Ftdi::Eeprom::init_defaults

### Description
Initializes the EEPROM with default values.

### Method
int init_defaults(char *manufacturer, char *product, char *serial)

### Parameters
- **manufacturer** (char *) - The manufacturer string.
- **product** (char *) - The product string.
- **serial** (char *) - The serial number string.

### Return Value
Returns 0 on success, or a negative error code on failure.
```

--------------------------------

### Ftdi::Context::serial()

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Gets the serial number string of the FTDI device.

```APIDOC
const std::string & Ftdi::Context::serial();
```

--------------------------------

### EEPROM Value Access Functions

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8h_source.html

Functions for getting and setting specific EEPROM values.

```APIDOC
## ftdi_get_eeprom_value

### Description
Retrieves a specific EEPROM value by its name.

### Signature
```c
int ftdi_get_eeprom_value(struct ftdi_context *ftdi, enum ftdi_eeprom_value value_name, int* value);
```

## ftdi_set_eeprom_value

### Description
Sets a specific EEPROM value by its name.

### Signature
```c
int ftdi_set_eeprom_value(struct ftdi_context *ftdi, enum ftdi_eeprom_value value_name, int value);
```
```

--------------------------------

### Ftdi::Context::open

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Opens an FTDI device connection.

```APIDOC
## Ftdi::Context::open

### Description
Opens an FTDI device connection.

### Method
int open(struct libusb_device *dev=0)

### Parameters
- **dev** (struct libusb_device *) - Optional: A pointer to a libusb_device structure to open. If null, the first available device is opened.

### Return Value
Returns 0 on success, or a negative error code on failure.
```

--------------------------------

### Write Chunk Size

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Get or set the write chunk size for data transfers.

```APIDOC
## set_write_chunk_size()

### Description
Sets the chunk size for write operations.

### Method
`int Ftdi::Context::set_write_chunk_size(unsigned int _chunksize)`

### Parameters
*   `_chunksize` (unsigned int) - The desired chunk size in bytes.

### Returns
On success, 0. On error, a negative value.
```

```APIDOC
## write_chunk_size()

### Description
Retrieves the current chunk size used for write operations.

### Method
`int Ftdi::Context::write_chunk_size()`

### Parameters
None

### Returns
An integer representing the current write chunk size in bytes.
```

--------------------------------

### Include Headers for libftdi1

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8c.html

Includes necessary headers for using libftdi1 and libusb.

```c
#include <libusb.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include "ftdi_i.h"
#include "ftdi.h"
#include "ftdi_version_i.h"
```

--------------------------------

### Read Chunk Size

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Get or set the read chunk size for data transfers.

```APIDOC
## set_read_chunk_size()

### Description
Sets the chunk size for read operations.

### Method
`int Ftdi::Context::set_read_chunk_size(unsigned int _chunksize)`

### Parameters
*   `_chunksize` (unsigned int) - The desired chunk size in bytes.

### Returns
On success, 0. On error, a negative value.
```

```APIDOC
## read_chunk_size()

### Description
Retrieves the current chunk size used for read operations.

### Method
`int Ftdi::Context::read_chunk_size()`

### Parameters
None

### Returns
An integer representing the current read chunk size in bytes.
```

--------------------------------

### USB Write Timeout

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Get or set the USB write timeout for FTDI operations.

```APIDOC
## get_usb_write_timeout()

### Description
Retrieves the current USB write timeout value.

### Method
`int Ftdi::Context::get_usb_write_timeout() const`

### Parameters
None

### Returns
An integer representing the USB write timeout in milliseconds.
```

```APIDOC
## set_usb_write_timeout()

### Description
Sets the USB write timeout value.

### Method
`void Ftdi::Context::set_usb_write_timeout(int _usb_write_timeout)`

### Parameters
*   `_usb_write_timeout` (int) - The desired USB write timeout in milliseconds.

### Returns
None
```

--------------------------------

### Initialization and Context Management

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8h.html

Functions for initializing, creating, and freeing FTDI context structures.

```APIDOC
## ftdi_init

### Description
Initializes an FTDI context.

### Signature
int ftdi_init (struct ftdi_context *ftdi)

```

```APIDOC
## ftdi_new

### Description
Creates a new FTDI context.

### Signature
struct ftdi_context * ftdi_new (void)

```

```APIDOC
## ftdi_deinit

### Description
Deinitializes an FTDI context.

### Signature
void ftdi_deinit (struct ftdi_context *ftdi)

```

```APIDOC
## ftdi_free

### Description
Frees an FTDI context.

### Signature
void ftdi_free (struct ftdi_context *ftdi)

```

--------------------------------

### USB Read Timeout

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Get or set the USB read timeout for FTDI operations.

```APIDOC
## get_usb_read_timeout()

### Description
Retrieves the current USB read timeout value.

### Method
`int Ftdi::Context::get_usb_read_timeout() const`

### Parameters
None

### Returns
An integer representing the USB read timeout in milliseconds.
```

```APIDOC
## set_usb_read_timeout()

### Description
Sets the USB read timeout value.

### Method
`void Ftdi::Context::set_usb_read_timeout(int _usb_read_timeout)`

### Parameters
*   `_usb_read_timeout` (int) - The desired USB read timeout in milliseconds.

### Returns
None
```

--------------------------------

### FTDI Initialization and Deinitialization

Source: https://www.intra2net.com/en/developer/libftdi/documentation/globals_f.html

Functions for initializing and deinitializing FTDI devices.

```APIDOC
## ftdi_init()

### Description
Initializes an FTDI device structure.

### Method
`ftdi_init(struct ftdi_context *ftdi)`

### Endpoint
N/A (Library Function)

## ftdi_deinit()

### Description
Deinitializes an FTDI device structure and frees associated resources.

### Method
`ftdi_deinit(struct ftdi_context *ftdi)`

### Endpoint
N/A (Library Function)

## ftdi_new()

### Description
Allocates and initializes a new FTDI context.

### Method
`struct ftdi_context *ftdi_new()`

### Endpoint
N/A (Library Function)
```

--------------------------------

### Class Members - o

Source: https://www.intra2net.com/en/developer/libftdi/documentation/functions_o.html

This section lists class members starting with 'o', including their associated classes.

```APIDOC
## Class Members - o

### offset
- **Class**: ftdi_transfer_control

### open()
- **Classes**: Ftdi::Context, Ftdi::Context::Private

### out_ep
- **Class**: ftdi_context

### out_is_isochronous
- **Class**: ftdi_eeprom

### Output
- **Class**: Ftdi::Context
```

--------------------------------

### Context::open(const std::string& description)

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Opens an FTDI device using a string description. This method is useful when the device can be uniquely identified by its description.

```APIDOC
## Context::open(const std::string& description)

### Description
Opens an FTDI device using a string description. This method is useful when the device can be uniquely identified by its description.

### Method
```cpp
int Context::open(const std::string& description)
```

### Parameters
* **description** (const std::string&) - The description string of the FTDI device.

### Returns
Returns 0 on success, or a negative error code on failure.
```

--------------------------------

### Ftdi::Eeprom Constructor

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Eeprom.html

Initializes a new instance of the Eeprom class.

```APIDOC
## Eeprom()

### Description
Initializes a new instance of the Ftdi::Eeprom class.

### Parameters
- **parent** (Context *) - Pointer to the parent Context object.
```

--------------------------------

### Get FTDI Latency Timer

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8c_source.html

Retrieves the current latency timer value from an FTDI device.

```c
int ftdi_get_latency_timer(struct ftdi_context *ftdi, unsigned char *latency)
{
unsigned short usb_val;

if (ftdi == NULL || ftdi->usb_dev == NULL)
ftdi_error_return(-2, "USB device unavailable");

if (libusb_control_transfer(ftdi->usb_dev, FTDI_DEVICE_IN_REQTYPE, SIO_GET_LATENCY_TIMER_REQUEST, 0, ftdi->index, (unsigned char *)&usb_val, 1, ftdi->usb_read_timeout) != 1)
ftdi_error_return(-1, "reading latency timer failed");

*latency = (unsigned char)usb_val;
return 0;
}
```

--------------------------------

### Initialize FTDI Context

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Creates and initializes a new FTDI context. Ensure to free the context using ftdi_free() when done.

```c
struct ftdi_context * ftdi_new(void)
{
return ftdi_new();
}
```

--------------------------------

### Latency and Modem Status

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8c.html

Functions for setting and getting the latency timer and polling modem status.

```APIDOC
## ftdi_set_latency_timer

### Description
Sets the latency timer for the FTDI device.

### Signature
int ftdi_set_latency_timer (struct ftdi_context *ftdi, unsigned char latency)

```

```APIDOC
## ftdi_get_latency_timer

### Description
Gets the current latency timer value.

### Signature
int ftdi_get_latency_timer (struct ftdi_context *ftdi, unsigned char *latency)

```

```APIDOC
## ftdi_poll_modem_status

### Description
Polls the modem status lines.

### Signature
int ftdi_poll_modem_status (struct ftdi_context *ftdi, unsigned short *status)

```

--------------------------------

### Ftdi::Context::Context

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8hpp_source.html

Constructor for the Ftdi::Context class. Initializes a new FTDI device context.

```APIDOC
## Ftdi::Context::Context

### Description
Constructor for the Ftdi::Context class. Represents a single FTDI device context.

### Method
Ftdi::Context::Context()

### Parameters
None
```

--------------------------------

### Chunk Size Configuration

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Sets and gets the read and write chunk sizes for data transfer.

```APIDOC
## set_read_chunk_size(unsigned int chunksize)

### Description
Sets the size of chunks for reading data.

### Method
set_read_chunk_size

### Parameters
#### Path Parameters
- **chunksize** (unsigned int) - Required - The size of read chunks.

### Returns
int

## set_write_chunk_size(unsigned int chunksize)

### Description
Sets the size of chunks for writing data.

### Method
set_write_chunk_size

### Parameters
#### Path Parameters
- **chunksize** (unsigned int) - Required - The size of write chunks.

### Returns
int

## read_chunk_size()

### Description
Gets the current read chunk size.

### Method
read_chunk_size

### Returns
int

## write_chunk_size()

### Description
Gets the current write chunk size.

### Method
write_chunk_size

### Returns
int
```

--------------------------------

### USB Timeout Configuration

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Gets and sets the USB read and write timeouts for the FTDI device.

```APIDOC
## get_usb_read_timeout() const

### Description
Gets the USB read timeout value.

### Method
get_usb_read_timeout

### Returns
int

## set_usb_read_timeout(int usb_read_timeout)

### Description
Sets the USB read timeout value.

### Method
set_usb_read_timeout

### Parameters
#### Path Parameters
- **usb_read_timeout** (int) - Required - The USB read timeout value.

## get_usb_write_timeout() const

### Description
Gets the USB write timeout value.

### Method
get_usb_write_timeout

### Returns
int

## set_usb_write_timeout(int usb_write_timeout)

### Description
Sets the USB write timeout value.

### Method
set_usb_write_timeout

### Parameters
#### Path Parameters
- **usb_write_timeout** (int) - Required - The USB write timeout value.
```

--------------------------------

### Ftdi::Context::open() [1/4]

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1Context.html

Opens the FTDI device using a libusb_device pointer.

```APIDOC
int Ftdi::Context::open(struct libusb_device * _dev_ = 0);
```

--------------------------------

### ftdi_eeprom_initdefaults

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8h.html

Initializes the EEPROM structure with default values. This function sets up the basic configuration for the EEPROM, allowing for custom manufacturer, product, and serial number strings.

```APIDOC
## ftdi_eeprom_initdefaults

### Description
Initializes the EEPROM structure with default values. This function sets up the basic configuration for the EEPROM, allowing for custom manufacturer, product, and serial number strings.

### Signature
`int ftdi_eeprom_initdefaults (struct ftdi_context *ftdi, char *manufacturer, char *product, char *serial)`

### Parameters
*   **ftdi** (struct ftdi_context *) - Pointer to the FTDI context structure.
*   **manufacturer** (char *) - String for the manufacturer's name.
*   **product** (char *) - String for the product's name.
*   **serial** (char *) - String for the serial number.
```

--------------------------------

### Ftdi::Context::write_chunk_size()

Source: https://www.intra2net.com/en/developer/libftdi/documentation/functions_w.html

Gets or sets the chunk size for writing operations in Ftdi::Context.

```APIDOC
## Ftdi::Context::write_chunk_size()

### Description
Gets or sets the chunk size for writing operations.

### Method
(Not specified in source, likely a C function call)

### Endpoint
(Not applicable for C library functions)

### Parameters
(Parameters not specified in source)

### Request Example
(Not applicable for C library functions)

### Response
(Response details not specified in source)
```

--------------------------------

### List Begin Iterator

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Returns a begin iterator for the list of FTDI contexts. Used for iterating through the discovered devices.

```cpp
List::iterator List::begin()
{
  return d->list.begin();
}
```

--------------------------------

### File Members - w

Source: https://www.intra2net.com/en/developer/libftdi/documentation/globals_w.html

This section lists members starting with 'w' found in the ftdi.h file.

```APIDOC
## File Members - w

### Description
This section lists members starting with 'w' found in the ftdi.h file.

### Variables
- **WAIT_ON_HIGH** : ftdi.h
- **WAIT_ON_LOW** : ftdi.h
- **WRITE_EXTENDED** : ftdi.h
- **WRITE_SHORT** : ftdi.h
```

--------------------------------

### Ftdi::List::Private Constructor

Source: https://www.intra2net.com/en/developer/libftdi/documentation/classFtdi_1_1List_1_1Private.html

Initializes a new instance of the Private class, taking a pointer to an ftdi_device_list.

```APIDOC
## Ftdi::List::Private::Private()

### Description
Constructor for the Private class. It initializes the internal state with a provided `ftdi_device_list`.

### Signature
`Private(struct ftdi_device_list * __devlist_)`

### Definition
Defined in `ftdi.cpp`, line 514.
```

--------------------------------

### FTDI Utility Functions

Source: https://www.intra2net.com/en/developer/libftdi/documentation/globals_func.html

Utility functions for error handling, listing devices, and getting library information.

```APIDOC
## ftdi_get_error_string()

### Description
Returns a string describing the last error that occurred.

### Method
(Not specified, typically C function call)

### Endpoint
N/A

### Parameters
N/A

### Request Example
N/A

### Response
N/A

## ftdi_get_library_version()

### Description
Returns the version of the libftdi library.

### Method
(Not specified, typically C function call)

### Endpoint
N/A

### Parameters
N/A

### Request Example
N/A

### Response
N/A

## ftdi_list_free()

### Description
Frees the memory allocated for a list of FTDI devices.

### Method
(Not specified, typically C function call)

### Endpoint
N/A

### Parameters
N/A

### Request Example
N/A

### Response
N/A

## ftdi_list_free2()

### Description
Frees the memory allocated for a list of FTDI devices (alternative version).

### Method
(Not specified, typically C function call)

### Endpoint
N/A

### Parameters
N/A

### Request Example
N/A

### Response
N/A

## ftdi_poll_modem_status()

### Description
Polls the modem status lines of the FTDI device.

### Method
(Not specified, typically C function call)

### Endpoint
N/A

### Parameters
N/A

### Request Example
N/A

### Response
N/A

## ftdi_set_usbdev()

### Description
Sets the USB device context for the FTDI device.

### Method
(Not specified, typically C function call)

### Endpoint
N/A

### Parameters
N/A

### Request Example
N/A

### Response
N/A
```

--------------------------------

### Initialize and Free FTDI Context

Source: https://www.intra2net.com/en/developer/libftdi/documentation/ftdi_8cpp_source.html

Demonstrates the constructor and destructor for the Ftdi::Context class, which handles the initialization and cleanup of the underlying ftdi_context. Ensure proper cleanup to avoid resource leaks.

```cpp
namespace Ftdi
{

class Context::Private
{
public:
Private()
: open(false), ftdi(0), dev(0)
{
ftdi = ftdi_new();
}

~Private()
{
if (open)
ftdi_usb_close(ftdi);

ftdi_free(ftdi);
}

bool open;

struct ftdi_context* ftdi;
struct libusb_device* dev;

std::string vendor;
std::string description;
std::string serial;
};

Context::Context()
: d( new Private() )
{
}

Context::~Context()
{
}

bool Context::is_open()
{
return d->open;
}

```
Tokens:
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