Sleep won't wake up

I can get the Photon to do most things I want, but it absolutely refuses to wake up after a timed deep sleep period. This is very simple. What am I doing wrong please?
I am using the Photon as a Central Heating controller powered from a solar charged battery. To save power I want to switch it off during the later hours of darkness.
Device goes to sleep fine - power consumption drops to almost zero (important). After 40 minutes the LEDs stay off and it needs a press of the reset button to get things going again.

Setup and loop code is thus:

void setup()
    Particle.function("digitalread", tinkerDigitalRead);
    Particle.function("digitalwrite", tinkerDigitalWrite);
    Particle.function("analogread", tinkerAnalogRead);
    Particle.function("analogwrite", tinkerAnalogWrite);

    tinkerDigitalWrite("D0 LOW");                   // CH control set safe
    tinkerDigitalWrite("D1 LOW");                   // HW control set safe
    pinMode(2, INPUT_PULLDOWN);                     // CH status input
    pinMode(3, INPUT_PULLDOWN);                     // HW status input
    pinMode(4, INPUT_PULLDOWN);                     // pump status input
    pinMode(7, OUTPUT);                             // LED driver is output
    pinMode(10, INPUT);                             // Top HW temp
    pinMode(11, INPUT);                             // Bottom HW temp
    pinMode(14, INPUT);                             // Supply voltage (12V)

void loop()
    delay(200);          // 200ms loop delay
    if (Time.hour() > 0 && Time.hour() < 10) {
        tinkerDigitalWrite("D7 HIGH"); 
        tinkerDigitalWrite("D7 LOW");
        if (sleeping == false) { 
            System.sleep(SLEEP_MODE_DEEP, 2400);  // sleep for 40 minutes
            sleeping = true;
    else {
        tinkerDigitalWrite("D7 LOW");
        sleeping = false;

I did a little searching around, and if I understand correctly, waking from deep sleep is like powering it up after it is off, so doesn’t the code stop executing after System.sleep(), never executing the rest of the code - sleeping will never be true.

** Update - check here…


Also, try declaring your pins with their proper names, e.g. A1/D1. Currently, it could be either. I’m not sure how your tinkerDigitalWrite function looks like, but it might be calling pins before declaring them.

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Please try adding this in your source code (outside of any function)


For testing, it’s probably a good idea to reduce the sleep time to a few seconds! :slight_smile:


PS: The 0.4.5 firmware will do this automatically so no need for that in later versions.

Without changing any other code, I reduced the deep_sleep period to 40 seconds. It worked - the Photon sprang into life again without the help of the reset button. I then extended the sleep period to 80 seconds - that worked OK too. Tonight’s experiment is to try a 180 second sleep period. I shall post results tomorrow.

Thanks for your suggestions guys!

180 second deep sleep period worked and woke up OK. I will not push the period further as the sleep to wake ratio is now about 50:1 so I could only gain about another 1-2% battery life extension. Not worth the hassle.
Could there be a limit as to how long one is allowed to “deep sleep” and still wake up? Maybe some counter eventually overflows? If I ever find out what the limit is, I’ll certainly post it here!


Did you try the STARTUP() change I mentioned above?

I haven’t tried that yet. I’ll see how tonight’s sleep goes then try Startup() tomorrow.
Fighting with Windows 10 at the moment!

Yes I did add the STARTUP line and that seems to have sorted the problem. A 9 minute deep sleep went off OK so last attempt is for a 20 minute deep sleep.
Many thanks for your suggestion.

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