16f946

**jderson** · - 9th March 2009, 05:35

I have been working with a 16F946 driving an 8 digit multiplexed LCD. Attached is a "HELLO WORLD" demo program for those interested. Please note the pin connections to the LCD from the PIC are arbitrary, and I made mine for the convenience of the PCB layout guy (me!).

Dave

**bogdan** · - 9th March 2009, 12:16

why did you PIR2.4 = 0 ?

**jderson** · - 9th March 2009, 13:12

Page 167 of the data sheet, "Configuring the LCD Module" says to do this. Apparently, you cannot write to the LCDDATA registers at certain times. The LCD Interrupt (PIR2.4) is there to prevent attempts to do this. I haven't gotten that far into it yet.

**bogdan** · - 10th March 2009, 00:10

i think you should use it just when you use the LCD interrupts (...should be Type B)... i will check if will work without PIR2.4 = 0

**jderson** · - 10th March 2009, 03:43

Thank you for the advice!

**jderson** · - 15th March 2009, 03:45

It seems the "HELLO WORLD" program I posted has problems. If certain characters are added to the seventh digit, the second digit becomes corrupted. The attached program is the same as the other one, with the digit "8" added after the "D" in "WORLD". You see that the "W" loses the "L" segment. I believe that this is happening because I'm trying to write characters at the wrong time. I have tried using "Type-B waveforms" and the LCD interrupt, but I don't understand how to use this interrupt. Does anyone have any ideas? Thank you.