Project 31:
Arduino Shield: Dual 4-bit 7-Segment LED Displays


           v1.0 Schematic                     v1.0 Board Layout                           v1.0 PCB                         Backside: TM1637


v1.0 Bill of Materials


   v1.1 Schematic                 v1.1 Board Layout                      v1.1 PCB                        v1.0 Operation (Video)


v1.1 Bill of Materials



In this project two 4-bit 7-segment LED displays are mounted on an Arduino UNO R3 shield. They are used to show:

- date and time

- temperature in C and humidity Percentage



C/C++ code has been written to exercise the 7-segment displays.

Located under Arduino | File | Examples | Examples from Custom Libraries | TM1637 you will find the sketch TM1637.ino which is used as a base for my code.

I have commented out all of the original code and placed it at the bottom of the sketch; the new code is at the top of the sketch.


Alternative Temp/HumiditySensor:

v1.0 uses the BME280 Temp/Humidity/BP sensor from China. Sketch TM1637Test_2.ino developed is based on Adafruit library code.

v1.1 uses the SHT40 Precision Temp/Humidity sensor from China. Sketch SHT40_Test_2.ino developed is based on Adafruit library code.

The nice thing about the BME280 and SHT40 sensors is that they share 4 pins in the same physical positions so one sensor can be swapped out for the other.


v1.1 uses the PCF8523 RTC from Adafruit. Sketch PCF8523_2.ino developed is based on Adafruit library code.


Next Steps:

As you assemble the project, test the displays first then the RTC and then the sensor. This way you'll know rimmediately which module might be giving you grief, if any.


Final Test Code:

If all is well then the final test code is Test_3_Modules.ino.





Updated 2024-04-10 @ 8am