Displays projects

A short project that can be modified by other users. Once the code is uploaded, TM1637 will display 00:00, after that you can use the 4×4 keypad array to type how long the timer should go (4 digits should be pressesed, 5th press will trigger the countdown, you can press anything for the 5th one). You can use the function at the bottom of the code to modify the result once the timer ends. Note: No code for the letters parts (outer right side of the 4×4 keypad) yet. bugs might be encountered when letters are used.
A simple light meter. It’s not calibrated to any meaningful scale, but the digital readout shows a higher number the brighter is the light falling on the photoresistor.
I cascaded four SN74HC595 shift registers to control 32 LEDs on 4 registers using 3 wires. I am adding a I2C 20×4 LCD screen to display the register and led values. I might add a standard 16×2 LCD screen to show up it is done.