If you want to connect 3.3V devices (sensors, memory cards etc.) to a 5V micro controller, or the other way around, you will most likely need level converter. Not many micro controller, running on a 3.3V power supply, can accept 5V signals on their inputs and outputs, without damage.
This tiny board works with max. data transfer rates of 28.8 kBaud, and it operates in both directions the same way (bi directional).
– power supply 5V and 3.3V required – 4 bi-directional signal lines – 3.3V to 5V and 5V to 3.3V signal conversion at max. 28800 bps.
Typical applications are for UART interfaces, 1-wire interface, I2C and SPI interface, Atmel ICSP interface etc.