pyftdi F232H - Lock on High State for CBUS pins

Hello,

Hello

With FTPROG i have switched the cbus_0 on "DRIVE1" and the LED turned on. Then i switched to "DRIVE0" but the LED stays into HIGH state.

Please could you explain why this is happening ? What should i do ?

Also, i have difficult to understand what i should put into theses functions to control the GPIOs:

Thanks a lot for your help!! :) Clément

Mar 04 '21 14:03 kelyrr

Whenever you update the EEPROM, you need to power cycle the device so that the EEPROM content is read and used.

Usage example on an UM232H board (FT232H module):

Load the current EEPROM content into a file pyftdi/bin/ftconf.py -P 15ba:002a -o ft232h.ini ftdi://:232h/1
Create a backup file if something goes wrong cp ft232h.ini ft232h_backup.ini

Edit the INI file

[values]
; ...
cbus_func_8 = DRIVE0
cbus_func_9 = DRIVE1

Update the EEPROM pyftdi/bin/ftconf.py -i ft232h.ini -l values -u ftdi://:232h/1
Unplug/plug back the UM232H module
- yellow led lights up, green led is off

Edit the INI file

[values]
; ...
cbus_func_8 = DRIVE1
cbus_func_9 = DRIVE0

Update the EEPROM pyftdi/bin/ftconf.py -i ft232h.ini -l values -u ftdi://:232h/1
Unplug/plug back the UM232H module
- green led lights up, yellow led is off

Edit the INI file

[values]
; ...
cbus_func_8 = GPIO
cbus_func_9 = GPIO

Unplug/plug back the UM232H module
- Now the module is ready to accept CBUS commands, so that AC8 and AC9 output can be changed dynamically

Run a small Python test On FT232H, CBUS drivable pins are ACBUS5, ACBUS6,ACBUS8, ACBUS9, from FT232H datasheet, therefore:

AC5 is b0, AC6 is b1, AC8 is b3, AC9 is b4.
to use AC8 and AC9, the mask is therefore 0b1100 or 0x0c; to use GPIO as output, the direction is 0xc as well

#!/usr/bin/env python3

from time import sleep
from pyftdi.ftdi import Ftdi, FtdiError
from pyftdi.eeprom import FtdiEeprom

ftdi = Ftdi()
ftdi.open_from_url('ftdi://:232h/1')
# sanity check: device should support CBUS feature
assert(ftdi.has_cbus == True)
eeprom = FtdiEeprom()
eeprom.connect(ftdi)
# sanity check: device should have been configured for CBUS GPIOs
assert(eeprom.cbus_mask & 0xc == 0xc)
# configure CBUS8 and CBUS9 as output
ftdi.set_cbus_direction(0xc, 0xc)
loop = 10
# alternate led blinking
while loop:
    loop -= 1
    ftdi.set_cbus_gpio(0x8)
    sleep(0.2)
    ftdi.set_cbus_gpio(0x4)
    sleep(0.2)
ftdi.close()

ft232h_led_cbus