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The MicroFTX is out of stock. Please consider the Micro1v8 for an improved version of the MicroFTX with LEDs and out-of-the-box support for 1.8V serial devices.

Micro1v8 (2-Pack) - USB to 1.8V Serial Adapter with LEDs - FTDI FT230X chip

International buyers: Our inventory is "Fulfilled by Amazon" which means that it's up to Amazon to decide where they ship. Currently, they do offer international shipping on our products to most countries. Thank you!

Drivers

$ adduser $USER dialout

SUBSYSTEM=="usb", ACTION=="add", \
  ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6015", GROUP="plugdev"

Comparison to Older Chips

The FT230X is very similar to FTDI’s older chips, like the FT232R series. In general, a lot of code and tools for the FT232R are likely to work with few changes.

Bitbang GPIO

The FT230X supports bitbang GPIO (general-purpose input/output) modes that allow you to set and read digital pins directly. It’s a great way to let your computer drive a simple binary output, or to read the state of a switch. For full details, see the FT230X website and datasheet. FTDI’s bitbang app note AN232R-01 hasn’t been updated for the FT-X series of chips yet, but the setup and usage of bitbang mode is essentially the same.

Two forms of bitbang are supported. They are enabled with FD_SetBitMode (D2XX) or ftdi_set_bitmode (libftdi):

• BITMODE_BITBANG uses the RX, TX, CTS, and RTS pins and works out of the box
• BITMODE_CBUS uses the CBx pins, but needs to be enabled first in the EEPROM

On Linux, libftdi provides a pretty easy way to use bitbang. The python bindings are poor, but it’s straightforward in C. This program will toggle the RX, TX, CTS, and RTS pins every time it’s run:

#include <ftdi.h>
#include <err.h>

int main(int argc, char *argv[])
{
    struct ftdi_context ftdi;
    unsigned char x;

    /* Initialize and find device */
    if (ftdi_init(&ftdi) < 0)
        err(1, "ftdi_init");

    if (ftdi_usb_open(&ftdi, 0x0403, 0x6015) < 0)
        err(2, "can't open device");

    /* Enable bitbang */
    if (ftdi_set_bitmode(&ftdi, 0xff, BITMODE_BITBANG) < 0)
        err(3, "can't enable bitbang mode");

    /* Read state & flip it */
    if (ftdi_read_pins(&ftdi, &x) < 0)
        err(4, "can't read");
    x ^= 0xff;
    if (ftdi_write_data(&ftdi, &x, 1) < 0)
        err(5, "can't write");

    /* Close device */
    ftdi_usb_close(&ftdi);
    ftdi_deinit(&ftdi);

    return 0;
}

To test it out, download this file as ftdi-bitbang.c, compile, and run it:

$ sudo apt-get install libftdi-dev build-essential
$ gcc -o ftdi-bitbang ftdi-bitbang.c -lftdi
$ ./ftdi-bitbang

Non-standard Baudrates

The FT230X supports custom baudrates up to 3Mbaud. If you’re using Python’s pySerial module, custom baudrates should just work like any other baudrate:

#!/usr/bin/python
import serial

ser = serial.Serial(port = "/dev/ttyUSB0", baudrate = 2000000)
ser.write("hello, world")
ser.close()

Here is a low-level example of how to configure custom baudrates in C on a Linux system:

#include <termio.h>
#include <fcntl.h>
#include <err.h>
#include <linux/serial.h>

static int rate_to_constant(int baudrate) {
#define B(x) case x: return B##x
    switch(baudrate) {
        B(50);     B(75);     B(110);    B(134);    B(150);
        B(200);    B(300);    B(600);    B(1200);   B(1800);
        B(2400);   B(4800);   B(9600);   B(19200);  B(38400);
        B(57600);  B(115200); B(230400); B(460800); B(500000); 
        B(576000); B(921600); B(1000000);B(1152000);B(1500000); 
    default: return 0;
    }
#undef B
}    

/* Open serial port in raw mode, with custom baudrate if necessary */
int serial_open(const char *device, int rate)
{
    struct termios options;
    struct serial_struct serinfo;
    int fd;
    int speed = 0;

    /* Open and configure serial port */
    if ((fd = open(device,O_RDWR|O_NOCTTY)) == -1)
        return -1;

    speed = rate_to_constant(rate);

    if (speed == 0) {
        /* Custom divisor */
        serinfo.reserved_char[0] = 0;
        if (ioctl(fd, TIOCGSERIAL, &serinfo) < 0)
            return -1;
        serinfo.flags &= ~ASYNC_SPD_MASK;
        serinfo.flags |= ASYNC_SPD_CUST;
        serinfo.custom_divisor = (serinfo.baud_base + (rate / 2)) / rate;
        if (serinfo.custom_divisor < 1) 
            serinfo.custom_divisor = 1;
        if (ioctl(fd, TIOCSSERIAL, &serinfo) < 0)
            return -1;
        if (ioctl(fd, TIOCGSERIAL, &serinfo) < 0)
            return -1;
        if (serinfo.custom_divisor * rate != serinfo.baud_base) {
            warnx("actual baudrate is %d / %d = %f",
                  serinfo.baud_base, serinfo.custom_divisor,
                  (float)serinfo.baud_base / serinfo.custom_divisor);
        }
    }

    fcntl(fd, F_SETFL, 0);
    tcgetattr(fd, &options);
    cfsetispeed(&options, speed ?: B38400);
    cfsetospeed(&options, speed ?: B38400);
    cfmakeraw(&options);
    options.c_cflag |= (CLOCAL | CREAD);
    options.c_cflag &= ~CRTSCTS;
    if (tcsetattr(fd, TCSANOW, &options) != 0)
        return -1;

    return fd;
}

Download this example: linux-custom-baudrate.c.

EEPROM Customization

The FT230X includes a 2048-byte reprogrammable EEPROM that configures the chip. Features that can be customized in the EEPROM include:

• USB vendor ID, product ID, device strings
• Device serial number
• I/O pin drive strength
• UART signal polarity inversion
• CBUS pin configuration, allowing each pin to be selected as:
  • TX/RX LED outputs
  • Clock output (6 MHz, 12 MHz, 24 MHz)
  • USB frame toggle (toggles every USB frame)
  • USB sleep status and control
  • Battery charge detection output
  • Bitbang GPIO
  • etc.

The easiest way to reprogram the EEPROM is using FTDI’s FT_Prog utility for Windows. Version 2.6.6 and later support the FT-X series chips. The user manual has more information.

The open-source libftdi library includes functions to access and change the EEPROM contents, and a standalone utility ftdi_eeprom that uses these functions. However, libftdi’s FT-X support is not necessarily complete and may not yet have been updated to support the FT-X chips. Note that incorrectly changing the EEPROM contents may lead to a chip that is difficult to recover.

Other third-party tools to program the EEPROM exist, like ftx-prog.

Design Files

Use these for reference, or if you want to incorporate this design into your own boards. Note that Eagle is required to open the layout files.

Revision 1 was sold before June 2013; may include FTDI chips with known errata.

• ftx-r1-schematic.pdf (PDF schematic)
• ftx-r1-layout.pdf (PDF layout)
• ftx-r1.zip (Eagle PCB schematic and layout)

Revision 2 can be identified by 2 white dots on the bottom silkscreen, and incorporates new FTDI chip revisions and larger capacitors.

• ftx-r2-schematic.pdf (PDF schematic)
• ftx-r2-layout-top.pdf (PDF layout, top)
• ftx-r2-layout-bot.pdf (PDF layout, bottom)
• ftx-r2.zip (Eagle PCB schematic and layout)

Revision 3 can be identified by 3 white dots on the bottom silkscreen. The default configuration is now set by traces which must be cut to change.

• ftx-r3-schematic.pdf (PDF schematic)
• ftx-r3-layout-top.pdf (PDF layout, top)
• ftx-r3-layout-bot.pdf (PDF layout, bottom)
• ftx-r3.zip (Eagle PCB schematic and layout)

FTDI Errata

FTDI has announced some errors in very early (Revision B) versions of the FT230XQ chip, which were used in MicroFTX boards sold in 2012. These errors, and their workarounds, are detailed in FTDI’s Technical Note TN_139.

All MicroFTX boards shipped since June 2013 have Revision D or later silicon, which resolves all known issues.