Use BlueTooth BLE and WiFi beacon frame to transfer sensor data, achieve ultra-low power. Based on CC2541, ESP8266 and NRF24l01+
I removed LDO from my NodeUSB (ESP8266) board, and use LiFePO4 battery to power it directly.
700 mAh able to run about 6 hours (345 minutes):
Then, I charged LiFePO4 battery (3.3V LDO directly) and ran another test:
That is 95 minutes, so about 27% of capacity, 190 mAh.
Second test is much batter (I charged longer this time, for 3 hours):
|2016-07-09 13:25:18||2016-07-09 16:07:58||162 minutes|
That is about 47% of the capacity.
If use 3.5V LDO to charge LiFePO4 battery, it can reach 95% of capacity. I will test it next week.
Today I started testing LiFePO4 battery. I had the idea of using LiFePO4 battery for few months. Now I just received the shipment early this week.
Few benefits use LiFePO4 battery:
Here is the schematic of BeWi based on Atmega168 and NRF24l01+:
After testing different chips/modules for WiFi, BLE beacons.
I am leaning toward to use NRF24l01+ send and listen BLE beacon frames.
Use another MCU (Arduino) with NRF24l01+ , anything can develop the firmware fairly easy. Cost will be low.