LCD another try?
Today i successfully triggered the /CS line and now I know it’s working. In measurements before my oscilloscope was to slow to display the changes on the /CS line…
So I conected the /CS line to the display’s Enable Pin. Moved R/W from A2 to A1 and adjusted my driver. I connected the display, loaded the module and …. nothing!
So I started my PC Scope Software, connected CH1 to /CS line and GND and … HARDWARE NOT FOUND. So I realized the fancy red led was dark and I checked the LPT-cable and the power connection. Hmm shouldn’t the red led on the power plug be on? Wow the transformer of the power plug din’t survive the night (btw. it was me going out not the power plug …). So I opened up a box and searched for a replacement power supply. Found an adjustable switching regulator and connected. The Software begann calibrating and reported: Calibration failed!
O.k. maybe the oscilloscope doesn’t like the switching power supply because of all this spikes and so…
But now back to topic: Why did the LCD stay blank… Maybe the bus interface is somehow to fast for that little display (but it worked with using 3 address lines). Is the Enable signaling correct? I will try using an inverter…
So I soldered a standard NPN inverted using a 2n3904 and 2 resistors connected everything, reloaded the kernel module and … nothing! Hmm it would be good having a working oscilloscope…
After that I think I’m gonna use the other solution…