BeagleBone UART nodejs

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1

Hello, I'm trying to use beaglebone hardare UART's but not much
success
The code is running in nodejs, i've installed nodejs serial port
module ( npm install serialport )
According to command " dmesg | drep tty " It shows 5 UARTS , I'm
trying to write to UART1 ( ttyO1)

var SerialPort = require("serialport").SerialPort
var serialPort = new SerialPort("/dev/ttyO1" , { baudrate: 9600 } );
serialPort.write("TEST");

The UART is opened and it writes, but I get nothing in Pin 24 of
header P9 (UART1_TXD) ,

Maybe is something related to pins muxing
Anyone dealed with UART's successfully?

I tryied also to use an usb-serial FTDI and it works correct on /dev/
ttyUSB0 , but if bone has hardware UART'S there's no need to use this
kind of converter..

Any help is welcome
Regards

2

Yes, its pin muxing.

root@beaglebone:~# cat /sys/kernel/debug/omap_mux/uart1_txd
name: uart1_txd.(null) (0x44e10984/0x984 = 0x0037), b NA, t NA
mode: OMAP_PIN_OUTPUT | OMAP_MUX_MODE7
signals: uart1_txd | mmc2_sdwp | d_can1_rx | NA | NA | NA | NA | NA

The mux is in mode 7 (NA) instead of mode 0 (uart1_txd) by default.
Use the script here:
http://groups.google.com/group/beagleboard/msg/bff6ba02dffcbf0f
I used it successfully to receive gps data on uart1_rxd.

Frank

3

Tanks for help, it works fine
But if I want to use more UARTS like UART2 I can't find it at /sys/
kernel/debug/omap_mux/
So how can I configure to have UART2 working?

Regards

4

That's a really good question, i would like to know the answer too.