Alphanumeric Display DLR2416
At work, one of our HPU pump control cards died, the control card looks like this and hosts an interesting four-digit alphanumeric display:
So, out comes the Arduino and breadboard, and downloaded the datasheet for the display (readily available if you google “DLR2416 datasheet”).
This display has 7 data pins to receive ASCII code as per the table below, with two address pins to select the ‘segment’.
After a bit trial and error, and thanks to this website by a guy who successfully interfaced with a similar display, I managed to get some characters displayed. I used a 74HC595 shift register to push out the data to the DLR2416, plenty of example code on the Arduino site for help with that.
The above schematic doesn’t show the 1microfarad decoupling capacitor from data to ground, which was required to prevent the display sometimes showing erroneous characters.
I played about a bit more, added a temperature sensor and had it display the current temperature, and managed to have the display scroll text.
Soldered to a protoshield, with space for an additional display if I can find one:
See below for code. Need to get my hands on an additional display to play with!