What is it?
It is a "flashlight","powerbank","battery gauge", "UPS"... I think it should be called "Multifunctional power supply"， but please do not focus on the name, we should focus on what can it do.
Why did you make it?
One reason is that my last product 18650 Battery shield V3 was copied and attached "wemos" logo. I stopped this product because it is not safe and does not work good. But the fake wemos company still sell it to customers that make me feel very angry. This time I want my supporters to have a good experience of power products so I decide to release this "Battery Gauge" .It has a WiFi chip(ESP8266) inside then you can send out battery status via WiFi! Some customers ask me if battery life could be monitored this time I will say "OK".
What makes it special?
WiFi chip inside: ESP-07s is used as MCU of this product you can program it yourself. WiFi works OK even you do not install antenna!(What I tested). Of course if you add IPEX antenna it will perform better. There is a SMT pad that allows you connect GPIO16 to RST. If you are interested in deep sleep function of ESP8266, you can give it a try!.
Max17043 : The MAX17043 use a sophisticated Li+ battery-modeling scheme, called ModelGauge™ to track the battery's relative state-of-charge (SOC) continuously over a widely varying charge/discharge profile. Unlike traditional fuel gauges, the ModelGauge algorithm eliminates the need for battery relearn cycles and an external current-sense resistor. Temperature compensation is possible in the application with minimal interaction between a µC and the device.
3V/5V output port:
- 3V output x3 Output: 1A(Total)
- 5V output x2
- 5V Type-A USB x1 Output:2.5A(Total)
- Charging current: 1.5A
LM39100 : LM39100 is a Low-Voltage Low-Dropout regulator. The reason I did not use a regulator like AMS1117 is because AMS1117 does not work when the battery drops to around 3.5V. If I regulate battery to 5V then convert to 3V with AMS1117 that also wastes a lot of power. LM39100 only has 410mV dropout so I can use LM39100 to regulate battery voltage directly with the most efficiency.
- Support 18650battery and other 3.7V-Li battery
- Display: SSD1306 0.96" OLED
- Display SDA: GPIO 4 (D2)
- Display SCL/SCK: GPIO 5(D1)
- Display and ESP07s and max17043 share the same IIC bridge.
- Support Deepsleep: smd pad(GPIO16->RST)
- Power button: Click to turn on, double click to turn off, long click to open flashlight
- Battery reverse protection
- Red LED: Reverse attention!
- Green LED： Blink means charing, remain "on" means full
- Battery status could be read by most of boards like Arduino,NodeMCU,RaspberryPi...etc
Sorry for my bad English. Please contact me first with any problems.