I have problem but I don't know where

[kenben]

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

i thought that too...i checked the the circuit i made for the buttons.....i plugged it to my first laptop...since i m getting no text on my lcd... i blindly tried updating the firmware....started off booting MD with left key pressed, then pressed once for 20MHz(i m using atmega644) then pressed down....i press yes...it actually sends firmware to MD

when i try these steps on my second laptop....it fails to send

yet...the lcd shows no text....if you are unclear of my situation...please read my earlier posts....thanks

[dmitri]

i do get the display "fw updater 16MHz down-ok. clock-up" and the led does not stops blinking....

So LCD does in fact work?

[kenben]

So LCD does in fact work?

yes ..it seems so

[dmitri]

So LCD does in fact work?

yes ..it seems so

Then it is keyboard wiring you have the problem with. Program the MegaDrum firmware with the ISP cable directly and check how your buttons work there.

[kenben]

alright ....i will try that right now and see what happens.....thanks

[kenben]

Then it is keyboard wiring you have the problem with. Program the MegaDrum firmware with the ISP cable directly and check how your buttons work there.

hi...i was asked to check my keyboard connector....i didnt really find any problem with...the circuit even looks right ....i followed the posted diagram....still...could not change the settings of MD

i was thinking...in synthex's 2.8v schematic.... the ground is pin 5, however in the diagram of the connector, pin 4 is ground.... is it not?

[dmitri]

Why are you mixing up my original schematics with Synthex's schematics? It's making it harder to help you.

[kenben]

Why are you mixing up my original schematics with Synthex's schematics? It's making it harder to help you.

wow..i cant believe...it didnt click me the schematics are that different..... thanks dmitri

theres one more thing however..... since i m using synthex's 2.8v schematic..... how do i make the keyboard connector for it?..... should i just take 4 switches...and positive of each switch goes to pin 1, 2,3 and 4...and negatives to all the switches goes to ground which is pin 5?

my apologies...i dont know if systhex has posted any schematic for the keyboard connector

[kenben]

never mind...i think i found....

thanks for all the help dmitri

[kenben]

I made a stupid mistake in designing the schematic on Eagle CAD.... here is the scenario:

if you look at the diagram below... the arrows are pointing at 2 VCC's. My plan was to connect them with a wire and remove one of the VCC point... but i forgot to remove it... I got the PCB etched so i cannot just pull out a wire. I was wondering how would it effect the circuit since the VCC is in parallel? Does anyone know how to fix this problem?