AITRIP 5 PCS 8 Digit 7 Segment Module MAX7219 8 Bit Digital Segment Tube LED Display Module Compatible with Arduino MCU/51/AVR/STM32/Raspberry Pi 4 Model B

They have a voltage out in addition to a voltage in, and by design, you should be able to daisy chain up to 8 of them. But they just require too much current at 5v to power them in series. The second and third ones in the chain glitch out, and the fourth one doesn't even light up. Running them at a lower voltage, like 3.8 or 4V, improves this slightly. Powering them in parallel solves the problem altogether. Running the CLK, DATA, and CS pins in series works just fine.

It took me a few months to get around to using this, then I had to figure out how to make it work. You clock in the bits on the rising edge of the clock, then bring the load input high. It is also possible to chain more than one together, but that's "an exercise for the student". And all this with only three control inputs. The bag included both a straight and a right-angle 5-pin header. I used the straight one to plug it into a breadboard, but you might want the right-angle one to put it on a jumper wire.

Mixing with unbranded chips. I Order them twice due to the unreliable quality of these 8 Digits 7 segments displays. I tested using several test conditions with codes that test all segments. (Arduino: Mega, Micro Pro, Mini. and Raspberry 4) The First Order I hah 2 out 5 bad displays (40% Failure). They had the MAX7219 Chips. The Segments were lighting all over the place no following the code The Second Order I had 4 out 5 bad displays (80% Failure). These displays have unmark Chips as seen in the provided image. Same type of failure seen with the LED displays from the first order The type of failures were . An another observation regarding these modules, the 4 Digits displays were soldered crooked on the board. 0 Quality Control. Even the package of the individual modules were different from the first order

One arrived only half soldered. How did this ever pass qc? Lol see also the title.

These arrived on time and all seem to work perfectly.