inversion of RxD TxD via eeprom conf

[schaechtelchen]

FTDI datasheets (e.g. FT232R) tells us : "Additionally, the UART signals can each be individually inverted and have a configurable high drive strength capability. Both these features are configurable in the EEPROM."

pyftdi EEPROM management should allow configuration of UARTs signal polarity

[enkiusz]

You should be able to do this with the ftconf.py tool by following these steps:

1. Read the EEPROM contents from the FTDI device and store it in a file:

davinci:~# python3 ftconf.py -v ftdi://ftdi:232:4/1 -o eeprom
vendor_id: 0x0403
product_id: 0x6001
type: 0x0600
self_powered: False
remote_wakeup: True
power_max: 100
has_serial: True
suspend_pull_down: True
out_isochronous: False
in_isochronous: False
manufacturer: SIBIT
product: SIBIT USB<>RS232 TTL CONVERTER
serial: 4
channel_a_driver: VCP
high_current: True
external_oscillator: 0
invert_TXD: False
invert_RXD: False
invert_RTS: False
invert_CTS: False
invert_DTR: False
invert_DSR: False
invert_DCD: False
invert_RI: False
cbus_func_0: TXLED
cbus_func_1: RXLED
cbus_func_2: GPIO
cbus_func_3: GPIO
cbus_func_4: SLEEP
davinci:~#

2. Edit the eeprom file to set the invert_txd or invert_rxd to "true":

davinci:~# cat eeprom-txd-inverted
[values]
vendor_id = 0x0403
product_id = 0x6001
type = 0x0600
self_powered = false
remote_wakeup = true
power_max = 100
has_serial = true
suspend_pull_down = true
out_isochronous = false
in_isochronous = false
manufacturer = SIBIT
product = SIBIT USB<>RS232 TTL CONVERTER
serial = 4
channel_a_driver = VCP
high_current = true
external_oscillator = 0
invert_txd = true
invert_rxd = false
invert_rts = false
invert_cts = false
invert_dtr = false
invert_dsr = false
invert_dcd = false
invert_ri = false
cbus_func_0 = TXLED
cbus_func_1 = RXLED
cbus_func_2 = GPIO
cbus_func_3 = GPIO
cbus_func_4 = SLEEP

You do not need to touch the raw EEPROM data in "[raw]".

3. Program the EEPROM to the FTDI device:

davinci:~# python3 ftconf.py -v ftdi://ftdi:232:4/1 -u -i eeprom-txd-inverted
vendor_id: 0x0403
product_id: 0x6001
type: 0x0600
self_powered: False
remote_wakeup: True
power_max: 100
has_serial: True
suspend_pull_down: True
out_isochronous: False
in_isochronous: False
manufacturer: SIBIT
product: SIBIT USB<>RS232 TTL CONVERTER
serial: 4
channel_a_driver: VCP
high_current: True
external_oscillator: 0
invert_TXD: True
invert_RXD: False
invert_RTS: False
invert_CTS: False
invert_DTR: False
invert_DSR: False
invert_DCD: False
invert_RI: False
cbus_func_0: TXLED
cbus_func_1: RXLED
cbus_func_2: GPIO
cbus_func_3: GPIO
cbus_func_4: SLEEP
davinci:~#