Crash after low power adc sleep #6
Description
When using LowPower.attachAdcInterrupt from Adruino LowPower on the Adafruit Feather M0 LoRaWAN, the devices freezes after wakeup from LowPower.sleep() upon calling any draw function unless begin() is called again. However when using the RTC instead of the ADC as wakeup source (with LowPower.sleep(2000) and attachAdcInterrupt() commented out), the problem does not occur.
Source code:
#include <ArduinoLowPower.h>
#include <DogGraphicDisplay.h>
DogGraphicDisplay DOG;
// Pin used to trigger a wakeup
#define VUSBPIN A0
// How sensitive to be to changes in voltage
const int margin = 100;
void adc_wakeup() {
return;
}
void setup() {
pinMode(LED_BUILTIN, OUTPUT);
pinMode(VUSBPIN, INPUT);
DOG.begin(17, 0, 0, 19, 18, DOGM128); //CS = 17, 0,0= use Hardware SPI, A0 = 19, RESET = 18, EA DOGM128-6 (=128x64 dots)
DOG.clear();
}
void loop() {
DOG.createCanvas(128, 64, 0, 0);
DOG.drawLine(0, 0, 127, 63);
DOG.drawCircle(50, 30, 20, false);
DOG.drawCircle(20, 20, 10, true);
DOG.drawRect(60, 20, 20, 10, true);
DOG.drawRect(80, 40, 10, 20, false);
DOG.drawCross(90, 20, 10, 10);
DOG.deleteCanvas();
digitalWrite(LED_BUILTIN, HIGH);
delay(500);
digitalWrite(LED_BUILTIN, LOW);
delay(500);
// Read the voltage at the ADC pin
int value = analogRead(VUSBPIN);
// Define a window around that value
uint16_t lo = max(value - margin, 0);
uint16_t hi = min(value + margin, UINT16_MAX);
LowPower.attachAdcInterrupt(VUSBPIN, adc_wakeup, ADC_INT_OUTSIDE, lo, hi);
LowPower.sleep();
LowPower.detachAdcInterrupt();
DOG.begin(17, 0, 0, 19, 18, DOGM128); //CS = 17, 0,0= use Hardware SPI, A0 = 19, RESET = 18, EA DOGM128-6 (=128x64 dots)
}