Huge current consumption due to setWatch() ?!?

Hi everyone,

I made a cooking timer with Espruino 2v01 based on a NRF52832 on a custom PCB. It has 2 buttons and a 7-segment led display. The display is off until the user presses any button. It then turns on and the user can set the timer and then start it. The display turns off after a few seconds, but can be turned on again if the user presses any button (so he/she can know when the timer will end). When the timer is finished, some leds on the PCB blink a few times to alert the user. He/she then has to press any button to stop the alarm.

My cooking timer works functionally well but consumes a lot of energy. About 7 mA at 6V (I have a LDO lowering the voltage to 3.3V then). I'm sure it's due to my code because I can go below 100 uA if only the GPIO are configured correctly. I have noticed that if I clear the 4 setWatch() I have with the clearWatch() command, it goes back to normal (less than 1 mA when connected by BLE, about 100 uA when disconnected). I'm not familiar with the way Espruino handles low-power modes on the NRF52832, but it seems that the device cannot turn off the external quartz nor decrease its frequency, thus consummating the 7 mA.

Can someone help me to understand what's happening ? I need the setWatch() to turn the display on when the user presses a button, so just removing them is not an option ;-) There is maybe another way to implement the behavior I need, I'm open to any suggestion.

The code is optimized with "simple optimization" and is minifyed from 20530 bytes to 11597 bytes. Here are the process.memory() results when it consumes 7 mA (first and second lines), I then clear all setWatch() at line 3 and call process.memory() again. At this point, the whole board consumes 1 mA (because of the BLE connexion), then about 100 uA after a few seconds.

>process.memory()
={ free: 1093, usage: 1157, total: 2250, history: 1000,  gc: 0, gctime: 4.79125976562, "stackEndAddress": 536924016, flash_start: 0, "flash_binary_end": 390268,  "flash_code_start": 442368, flash_length: 524288 }
>clearWatch()
=undefined
>process.memory()
={ free: 1157, usage: 1093, total: 2250, history: 1006,  gc: 0, gctime: 4.57763671875, "stackEndAddress": 536924016, flash_start: 0, "flash_binary_end": 390268,
  "flash_code_start": 442368, flash_length: 524288 }

The code is in copy if needed.

Thank you and best regards.

1 Attachment

• cooking_timer.js