Hardware Issues/ Enhancements
- ISSUE Stronger power supply. 5V operation works, but 3.3V battery does not. Starting to see evidence that this may be an issue with my build. Need to keep open minded.
- ENHANCEMENT Hall Effect sensors on measurement devices
- ENHANCEMENT I2C based counters for rainfall and wind anemometer revolution count
- ENHANCEMENT Full low current analysis
- Mount ESP32 on PCB and keep only what I need in the design
Troubleshooting
When RESET or initial power on happens on non 5V USB power (using LiIon battery and MCP1700)
WiFi radio begin() will fail and system reboots
second connect will pass
sequence fails again after deep sleep and timer WAKE
TODO: Scope 3.3V supply and look for any signs of droop
monitor regulator output and 3V3 pin on dev module
Observed that fully charged battery will RESET controller after deep sleep, but as voltage gets < ~4.1V controller stops resetting.
4:30am - Experiment start
19:10pm
Boot count starts to increment after deep sleep, but microcontroller randomly still RESETs
I now have a way to know when things are working properly
One can clearly see when boot count is getting RESET to 0
Left graph: ADC reported battery voltage vs. time
Right graph: bootCount vs. time
**Notice how bootCount periodically resets after incrementing for some time. This is typical behavior is the ESP32 RESETs when activating WiFi radio.
Long term TODO:
- Hall Effect sensor based wind and rainfall measurement
- I2C based wind counter, easier to periodically read instantaneous wind values with ULP
- Layout ESP32 on main PCB, get rid of the dev module entirely
- Really attack the deep sleep current support
- Add FET switch for powering down all peripherals while in deep sleep
- No power LED constantly drawing current
- LoRaWAN stack
Log of efforts
Power supply reboot debug issue
Ordered 500mA LDO’s from Microchip. TC1262 (qty 10)