A Mini weather station based on ESP-12. Include a BME280 or BME680 sensor chip on board, one or more DS18B20 onewire sensors. It's powered by a Lithium cell, can be for short time directly charged over present voltage input. A LDO with very low Iq included. Comes with voltage measurement for the connected battery. Hardware jumper for deep-sleep and a programming connector (charge the battery if +5...
As title says, 2 very simple PCBs with schematics
schottky diode and capacitor (ceramic / electrolytic doesn't matter) is part of smoothing and can be skipped for standard LED's, but it's needed e.g for self changing color ones
This is a battery powered sensor board based on the ESP8266 (ESP-12F).
By using a TPL5111 chip the battery consumption can be reduced to about 1µA when the ESP is not enabled. When the TPL5111 chip receives 5V at it's wake up pin this will turn the ESP on by enabling the 3.3V voltage regulator. At this moment you can run any program you want. If you want to turn the ESP off again you have to drive...
Water detector with 4 level stages. Each stage makes the 555 timer to give a supply period for the buzzer. The active buzzer transmits sound with a pause period between 0.5-3 seconds, depending on the level detected.
Schematics & PCB for battery spot welder controller board.
- Provides simple user interface
- Accepts pedal input ( with smart unintended-weld protection )
- Outputs precisely timed pulses for [https://www.banggood.com/custlink/KGDDEpKHCE](high-current relay)
- Very simple to solder, generous spacing and no SMD components
- Easy to remove DIP8 components ( MCU & DRIVER ) thanks to the space below...
This is a battery capacity indicator for 3.7V lithium ion batteries, using a bi-color LED (red-green) common cathode.
When the battery is from 100% to 50%, the LED stays green. When the capacity is from 50% to 20%, both LEDs turn on so it shows as yellow. When battery drops below 20% the green LED turns off leaving the red LED turned on.
It uses a schmitt trigger for both LEDs to prevent bou...