- Tue May 26, 2015 11:15 am
#18517
I have a new module that I developed that I'd like to share but before I produce it I'd like to get some feedback and see if there is any interest in it.
The module is the same size as the NodeMCU module and shares many of the same pins. It's not menat so much for development as it is for deployment. I say that because it doesn't have a USB to TTL converter or a reset button. What it does do is this:
The module has 3 connectors to plug in a solar panel, a Li-ion battery, and a backup battery. If there is enough energy the solar panel will charge the Li-Ion battery. If there is an extended period of time that elapses without charging, the circuit will automatically switch to the backup battery. The TPS63011 can boost from as low as 1.8V so 2 AA/AAA batteries can be used as backup. As long as sleep modes of the ESP are used you should never loose power. I've been testing this with different small solar panels with favorable results.
I've attached the schematic and board plots and will be releasing this as open source. I found only 1 minor design error on the prototype that I fixed with a jumper wire for the initial prototypes. Based on my findings of looking at the ESP-12 module I am considering changing this from accepting the ESP module to just placing the ESP8266EX chip directly onto this board.
Any thoughts or comments (both good or bad) would be greatly accepted.
Thanks,
George
The module is the same size as the NodeMCU module and shares many of the same pins. It's not menat so much for development as it is for deployment. I say that because it doesn't have a USB to TTL converter or a reset button. What it does do is this:
- Uses the TI BQ25505 Energy Haversting chip. This chip allows energy havesting down to 100mV input and has control for battery charging.
- It uses the TI TPS63011 Buck/Boost regulator which allows the voltage to be raised or lowered to provide power to the ESP module. This level can be switched at 2.8V or 3.3V.
- Because I had room I added a TI HDC1000 temperature and humidity chip.
The module has 3 connectors to plug in a solar panel, a Li-ion battery, and a backup battery. If there is enough energy the solar panel will charge the Li-Ion battery. If there is an extended period of time that elapses without charging, the circuit will automatically switch to the backup battery. The TPS63011 can boost from as low as 1.8V so 2 AA/AAA batteries can be used as backup. As long as sleep modes of the ESP are used you should never loose power. I've been testing this with different small solar panels with favorable results.
I've attached the schematic and board plots and will be releasing this as open source. I found only 1 minor design error on the prototype that I fixed with a jumper wire for the initial prototypes. Based on my findings of looking at the ESP-12 module I am considering changing this from accepting the ESP module to just placing the ESP8266EX chip directly onto this board.
Any thoughts or comments (both good or bad) would be greatly accepted.
Thanks,
George
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