I finished my little thermometer project using a 1.3" LCD display but through use I thought it was a bit small so this re-visit is to replace it with this Waveshare 2" LCD.
As both displays use the same interface I simply removed the faceplate and the 1.3" display then plugged the trailing wires from the 2" display into the appropriate pins on the PCB and switched on..
And as expected the screen was drawn on one side as this new display has a resolution of 320x240 compared to the 1.3" display resolution of 240x240.
The first fix is to tell the program I'm using a different screen resolution.
Then to centre the text.
At this point I should remake the main PCB and faceplate but I'm only going to get a new faceplate and build another main board but with right angled headers.
and as usual I need to wait for the faceplate to arrive..
ScriptWhile I'm waiting on the faceplate I thought I'd measure the current each display uses:
1.3" Display with the backlight set to 40000 (scale - 0 to 65535) = 46mA
2" Display with the backlight set to 40000 = 106mA
2" Display with the backlight set to 30000 = 86mA
- at 106mA the whites were flairing a bit and at 86mA it looks just about right, not dull and not super bright.
Now I'll run the 2" version on battery to see how long it lasts.
On this 8000mAh battery it lasted 24 hours with the stay alive circuit in place and 35 hours when removed - nowhere near the calculated value.
OK, so the new front panel has arrived but I don't have 2mm black bolts long enough to attach the display..one of these days I'll get it finished!
My silver powerbank is showing signs of bulging (it is very old) so it's heading to re-cycling. My new one has a bit larger capacity (27000mAh) so I'm re-running the duration test - results, well over five days.
Finally finished!