HiLetgo 2pcs 0.36" 4-Digit Tube LED Segment Display Module Red Common Anode TM1637 Drive Chip Tube Clock Display for Arduino UNO R3

They’re cheap, they work as advertised.

The media could not be loaded. Really simple to use 4 pins, have it plugged into an Arduino nano and I’m using it as a speedometer for racing games. Love how responsive it is.

I ordered 2 of these 4 digit LED modules to display battery voltage and current on my RV. They are very easy to use with the Arduino IDE and microcontroller and look great. However they are intended to display time with a colon in between the digits and don't have any decimal points. I have ordered a set of the display modules with decimel points instead if a colon for the finished product. Great display modules but Just beware these are only for time (or integers) and won't display any decimal values.Very easy to use with the AM1637 library on github.

The media could not be loaded. I was skeptical about using this display at first since the datasheet was a bad translation of Chinese to English. However, after looking over the datasheet and trying some things I was able to get the display working very well. I am able to accurately control each individual digits as well as the colon in the middle. The colon is the 'decimal point' of segment 2. I bought 6 of these since I know I will eventually use them and they work so well. I opted to use an MSP430 microcontroller to develop the controller on.

I received 2 of the 4 digit 7-segment LED displays. Internet search provided sites that provided a code example that I was able to use to test out the displays. Both units worked as expected. These displays are big and clear enough to suit my needs. A side note: these units use any 2 pins to drive the unit and do not use addressing like normal I2C - so each unit requires its own 2 pins so if you have any other I2C devices to drive you shouldn't use A4/A5 as usual for I2C for these units.

Update: The SoftwareSerial library is interrupt driven under the covers and that causes the 1637 updates to stutter resulting in long delays doing 1637 writes. This only happens if there is serial data arriving at the moment the 1637 write is occurring. To avoid this problem put a port.end() just before your 1637 writes and a port.begin() right after them. Serial gps data arriving at 9600 baud is unaffected at least for me - I only use GPRMC messages and discard everything else anyway so some of them might be affected but I don’t see any affect at all, except all of my 1637 writes now happen in 16–20ms.Original review:The 1637 part takes about 75ms per digit to write to on a nano. That is S L O W. They’re fine for clocks but not for anything with much else going on.These go in all my temp projects, the gps test clock, the portable lux meter, the square wave clock generator, the rf24 transmitter and receiver test fixtures, etc. They’re a little small for across-the-room viewing but are 1/4th the price of the Adafruit units.

Used it on two Raspberry Pi projects. One was a Raspberry Pi 2 and the other a Zero. For one I used it as a scrolling display on a MIDI keyboard and for the other I just displayed temperature and humidity data. I used the Adafruit Python libraries to drive it in both cases. There are plenty of Python libraries available for 7 segment displays on Raspberry Pi.The displays are bright and work as expected. What else could you want?

Unfortunately one of the displays had several segments not working. It seems that the onboard driver chip is defective. The other one worked fine. Brightness depends on how you drive them. When using PWM signals, the brightness can be controlled and completely turned off.So, I had to give em a one star review, because only one of them worked.