I've been trying to build a relatively simple set-up between TWO DUEs, using LEDs to flash/receive messages between each other in Morse-code style (LedComm).
Up to a point, this went well in 1.5.4 (!) but ever since 1.5.6-r2 things got really BROKEN!!
I've seen and read many other reports regarding DUE's "analogue problems".
In the below example: once I have used AnalogRead() - I can NOT seem to get the analogue-port back to OUTPUT mode. Compiling this code in 1.5.4 works fine and as expected - ANY release afterwards does not - including 1.6.5 (!!)
And even though I've seen and read many threads regarding Due's AnalogRead() problems, some also suggested several issues have been fixed in the meanwhile?!?!
// LED anode on Digital Pin 22, Cathode (via 220R) to A0
// for Arduino DUE:
const int anode = 22;
const int cathode = A0;
int reading = 0;
void setup() {
// analogReadResolution(12);
pinMode(anode, OUTPUT);
pinMode(cathode, OUTPUT);
Serial.begin(9600);
Serial.println("Analog readings:");
}
void loop() {
// LED off
digitalWrite(anode, LOW);
digitalWrite(cathode, LOW);
// Reverse Charge
digitalWrite(anode, LOW);
digitalWrite(cathode, HIGH);
delay(1);
// Measure
pinMode(cathode, INPUT);
reading = analogRead(cathode); //--> THIS is the culprit (!)
// report
Serial.println(reading,DEC);
// Led ON
//## --> DOES'T WORK SINCE 1.5.6-r2 upto & including 1.6.5 (!)
//## --> The LED remains OFF and never blinks ON again!
//## --> Works fine on 1.5.4, blinks -as expected.
pinMode(cathode, OUTPUT);
digitalWrite(anode, HIGH);
digitalWrite(cathode, LOW);
delay(50);
}
Note: My intention is to have multiple "Ledcomm-ports" on each DUE (but only using one at a time), so I will have multiple LEDs on multiple analogue/digital ports. And instead of running it from a main-loop, I've been using the DueTimer library and have the interrupt provide some stable frequency for communication.
Any help or insights would be GREATLY appreciated; to be honest this problem has been haunting me for over a year and has been a real show-stopper for me!!
You can spend 1h researching on-line, or spend 6 months on it. But, it won't be until you post something to the forum that you'll find what you're looking for
Due bug: Cannot use pin as digital after analogRead
Bug: analogRead() for Arduino Due should disable previous ADC channel before enabling new one
A work around for my above problem is said to use AnalogRead() on another (spare) port, to release the previous one. Okay... installing 1.6.5 again and giving that a try....
I hope these (clever) guys will release a fix for this as soon as...
