Hello guys,
I have 3 Arduino Due boards and I am receiving incorrect AnalogRead values compared with my multimeter measurement.
Very same symptoms as here
https://forum.arduino.cc/index.php?topic=491339.0
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Same issue on all analog input ports.
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Simple voltage divider scheme (attached my scheme). I am using potentiometer. It is just testing board where on real board instead of potentiometer will be 10k NTC thermistor.
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Serial output only shows 2 values. For 0-0.3V it show 512, for 0.3-3 it is 768 (10bit resolution)
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Board is supplied from my PCs USB port
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In my case it is same on all 3 boards.
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All my boards have desoldered DC jack and ICSP pins. I recieved this boards from colleague in this state. But I don’t think it should have some impact.
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What is most strange, I have one clone of Due board from ebay and there same scheme and code works correct. Attached photos of original and clone board.
I tried without success:
- Put 10k resistor between analog pin and GND
- Put 100nF capacitor between analog pin and GND
- Set INPUT_PULLUP
Here is my code
#define ReadPin A5
void setup() {
Serial.begin(9600);
pinMode(ReadPin,INPUT);
}
void loop() {
int sensorValue = analogRead(ReadPin);
Serial.println(sensorValue); //768 or 512
delay(250);
}
Thank you for your time!