SunRobotics TM1637 Digital Tube LED Clock 4 Digit Display Module For Arduino Electronic Components Electronic Hobby Kit

This LED driver is found in front panel controllers of consumer electronics such as DVD players. The added features such as the matrix keyboard scanning are useful in these applications. The typical application schematic is shown below. The TM1637 has a single pin for Data input (commands, LED segments) and Data output (key status). This pin can be connected to m bed MOSI and MISO using a series/pull-up resistor. The device also needs an SCK pin. The protocol is ''I2C-like'', but not compatible to I2C (very strange, uses commands instead of address + RW bits, you could not have more than one device on the same bus since the I2C address is not used). The library currently implements a bit-banged serial protocol to control the TM1637 using three pins (MOSI, MISO, SCK). It should also be possible to modify the lib and use a single Digital In Out pin instead of two separate pins for MOSI and MISO.