Control Led on Arduino using OpenWRT (TP Link MR-3020) serial com

1. Install modem driver on openwrt

root@OpenWrt:~# opkg install kmod-usb-serial kmod-usb-serial-ftdi

2. Attach Arduino to OpenWRT, and check on dmesg

[ 5182.260000] usb 1-1: new full-speed USB device number 3 using ehci-platform
[ 5182.430000] cdc_acm 1-1:1.0: ttyACM0: USB ACM device

3. Install coreutils-stty

root@OpenWrt:~# opkg install coreutils-stty

4. run coreutils

stty -F /dev/ttyACM0 cs8 9600 ignbrk -brkint -icrnl -imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke noflsh -ixon -crtscts

5. upload the sketch to Arduino.


int ledPin3 = 3;

int ledPin2 = 2;

int incomingByte;          // a variable to read incoming serial data into



void setup() {   

   Serial.begin(9600);     

   pinMode(ledPin3, OUTPUT);              

   pinMode(ledPin2, OUTPUT);              

}



void loop() {    

    if (Serial.available() > 0) {        // see if there's incoming serial data:

        incomingByte = Serial.read();     // read the oldest byte in the serial buffer

                                        //Preform the code to switch on or off the leds

        if (incomingByte == '1') {

            digitalWrite(ledPin3, HIGH);     //If the serial data is 0 turn LED 1 on

        }

        if (incomingByte == '2') {

            digitalWrite(ledPin3, LOW);     //If the serial data is 1 turn LED 1 off

        }

        if (incomingByte == '3') {

            digitalWrite(ledPin2, HIGH);     //If the serial data is 2 turn LED 2 on

        }

        if (incomingByte == '4') {

            digitalWrite(ledPin2, LOW);     //If the serial data is 3 turn LED 2 off

        }

    }

}

6. run this command on Openwrt terminal.

-- to turn on LedPin3

echo "1" >/dev/ttyACM0

-- to turn off Led 

echo "2" >/dev/ttyACM0