Posts Tagged: i2c

Driving 4×7 LED with 4 resistors only (kinda Charlieplexing)

Traditional way of connecting 4 digits x 7segment display to microprocessor suggest using 4 transistors and 12 resistors: Would You be interested in shrinking everything down to LED display and 4 resistors ONLY ? Then continue reading. Assuming one LED segment (digit's stick) drives 20mA current this setup can take up to 160mA of power (7segments+dot)*20 if we will use multiplexing (turning just one digit at a time, then next, then next,... an doing it very very fast). Even this trick takes too much ... Read more

Simple I2C protocol for advanced communication between Arduinos

- advanced communication between multiple Arduinos using I2C bus. - most online tutorials covers just one blinking LED with almost no practical use. Slave just executes ONE and SAME function every time Master asks about it. I'd like to outsource slave Arduinos for zillions of tasks. - simple protocol which enables to send any number of commands to Slave, opposing single return from simple Wire.onRequest(); Strong communication skills are always a key to success: Say we have one Arduino(Slave) dedicated for position ... Read more