Deeplseep issues / fix

[jvgelder]

I was having issues getting deep sleep to work using the battery (no usb power) and the regular esp functions esp_deep_sleep_start and esp_sleep_enable_timer_wakeup(). When I realized it had a bat boost converter I managed it to get it to work by:

pinMode(POWER_HOLD_PIN,OUTPUT);
digitalWrite(POWER_HOLD_PIN,HIGH);
gpio_hold(GPIO_NUM_12); // tell the esp to keep pin high even in sleep

I am not sure where this information belongs but i thought it might be useful for anyone else bonking his head against the wall.