I have connected an FTDI device to my computer, with the FTDI then connected to an Intel Edison Arduino breakout board using the 0RX and 1TX pins.
Here is the serial pin hookup:
Edison TX ------> FTDI RX
Edison RX ------> FTDI TX
To manage the GPIO on the Intel Edison, I followed the instructions provided in the top answer of this post:
To check my GPIO configurations, I ran the command:
cat /sys/kernel/debug/gpio
This output was displayed:
Nodejs code:
var SerialPort = require("serialport").SerialPort;
var port = "/dev/ttyMFD1";
var serialPort = new SerialPort(port, {
baudrate: 9600
}, false);
console.log("Open port: "+ port);
serialPort.open(function (error) {
if (error) {
console.log('Failed to open: '+error);
} else {
console.log('open');
serialPort.on('data', function(data) {
console.log('data received: ' + data);
});
var counter = 90;
setInterval(function () {
serialPort.write(String(counter)+ "\r\n", function(err) {
if(err) {
console.log('err ' + err);
}else{
console.log('Writing data ');
}
});
counter++;
if(counter>100)
counter =90;
}, 1000);
}
});
Upon running:
node uart.js
I noticed strange characters appearing even when no data was being sent to the Intel Edison.
Strange characters shown were:
To investigate if the nodejs script was causing the issue, I tried:
cat /dev/ttyMFD1
which resulted in showing the same odd characters without any outgoing data being sent to the Intel Edison.
I am puzzled by the appearance of these random characters without any active communication. Unsure if it's a GPIO configuration error or interference causing noise... What steps should I take to address/troubleshoot this situation?
In an attempt to further troubleshoot, I added the following code snippet within the serialPort on function:
var s = JSON.stringify(data);
console.log ("data: " + s);
The output from this code was:
[255,255,255,255]
UPDATE
It appears that the issue lies with the setInterval function. After removing it and implementing a for-loop test, I successfully sent characters over 10 rounds without encountering the garbled characters.