A small portable device featuring timer, clock, and calendar functions, equipped with a simple and functional interface and a truly long battery life.
A YouTube builder shows off how he created an Arduino board that's 7x larger than the real thing... powered by a hidden ...
or located under the following github pages github.io. Additionally in combination with the technical datasheet of microchip PCF8574-Datasheet. PCF8574_I2C::PCF8574 pcf{0x20, &Wire}; void setup() { ...