Communicate with serial port

I use colibri imx6 linux computer on module . when ı set gpio 40 like this

echo 40 > /sys/class/gpio/export            
echo high > /sys/class/gpio/gpio40/direction

I could not communicate with ttymxc2. I sent data over ttymxc2 but could not get any data …

I set gpio 40 pin high because I must use RS232 B for my gprs modem.

in this state I have a gprs modem connected to ttymxc1, I have a telit module connected to ttymxc2 that was sending a data but could not get data, I have a ttymxc 0 I use this port for communicate colibri imx6

how I can ı fix this problem ?


I guess you do the GPIO manipulation in order to poweroff the RS232 transceiver and connect your modem directly to the UART signals on CMOS level.

Please note that gpio 40 must be low to poweroff the transceiver. So you likely have now the modem’s output and the transceiver’s output connected together resulting in what you see.


How are you trying to communicate with ttymxc2?

with node application using serialport npm