www.megadrum.info

" When you connect pin 3 of the LCD to the ground you set LCD contrast to the maximum and black boxes in the top raw should stand out straight away. If they don't, your LCD is faulty. If they do, your Atmega is not working properly."

..... said dmitri

so this means... if you do see black boxes on the top row, the atmega is not working properly? Is it possible that the atmega's data lines are faulty? is there any way to check this (ignore other possibilities for now i.e. short circuits and all)

other thing i noticed.... i was just testing the continuity between the pins 4, 6, 11, 12 , 13 , 14 (data lines), there is actually very little continuity. i am guessing, there gates inside the atmega chip is linked resulting in some connection.

Finally here is my problem... i am using synthex's 2.8v schematic with the trimmer pot... i am able to see black boxes on top row, no VU meter though. I thought the lcd was faulty so i replaced it with a new one, still no change. The atmega is programmed. I got a PCB etheched so i guess the connections are correct. I hope i provided with enough info.

You either have a faulty/not programmed Atmega or a connection problem (shorts/breaks) between Atmega and the LCD.

You either have a faulty/not programmed Atmega or a connection problem (shorts/breaks) between Atmega and the LCD.

alright...i guess your suggestion worked...i reprogrammed the atmega, the lcd started working.... its shows the following message " Fw updater 16MHz DOWN-ok . up-clock".

the weird part is ...i used the PC to program the atmega...when i removed the the LPT serial cable and usb and now plugged the usb into my laptop....i see black boxes in the first row of the lcd again....(PIC18F2550 is programmed since usb is detected...i assume)

kenben wrote:i reprogrammed the atmega

With the bootloader? Now boot MD with left key pressed and update the firmware via MIDI-OX or MegaDrumUpdate.

With the bootloader? Now boot MD with left key pressed and update the firmware via MIDI-OX or MegaDrumUpdate.

alright so ...before i update the firmware...using MIDI-OX or MCT.....if i just plug in the usb (with no serial cables connected)...should i be getting anything on the lcd?

at the moment...when i plugin the usb...only black boxes appear in the first row... is that normal?

kenben wrote:alright so ...before i update the firmware...using MIDI-OX or MCT.....if i just plug in the usb (with no serial cables connected)...should i be getting anything on the lcd?

at the moment...when i plugin the usb...only black boxes appear in the first row... is that normal?

Boot MegaDrum with the LEFT key pressed. Can you see the bootloader text?

Boot MegaDrum with the LEFT key pressed. Can you see the bootloader text?

no ...i dont see anything except for the Black boxes in the first row

i just read something on one of the posts... when i boot MD with Left key pressed....the led is supposed to blink a few times then stop.....u get the text on LCD "fw updater 16MHz down-ok. clock-up"....you select the clock then press down for ok....

however on mine...after i programmed in Atmega... i do get the display "fw updater 16MHz down-ok. clock-up" and the led does not stops blinking....

once i remove the serial cable....the boot MD with left key pressed....nothing shows up except for black boxes

kenben wrote:no ...i dont see anything except for the Black boxes in the first row

This is strange...

Did you program the fuses correctly?

yes...i programmed the fuses....used the atmega644 config. and using 20MHz crystal

I suspect the buttons are not wired correctly so when you think you press LEFT you actually don't.