my problem

Started by made sadwuri July 25, 2007
hi all..
I am a beginner in microcontroler,i have a problem in programming microcontroller ATmega8535. I hope any one could help me..
I want to integrate LCD module to my ATmega 8535..according to literature, it should be set security and configuration bit first
on ponyprog. And i do that..but my LCD still doesn't work, so i change the set security and configuration bit (SUT and CKSEL)..
and accidentally my ATmega couldn't be downloaded anymore, there's comment "unknown device (24)".
I am so sad because it has happened 3 times, i mean i have broken 3 microcontroller.
is my atmega broken? could it be repaired?
i really need your help to solve my problem.
thanks so much.

________________________________________________________
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The ATmega8535 is shipped with CKSEL = "0001"and SUT = "10".
The clock source setting is therefore the Internal RC Oscillator with the longest startup time.
If you changed CKSEL to 0000, you have selected the external oscillator option. To be able to
reprogram your microcontrollers, you have to temporarily connect an external oscillator to pin 13 (XTAL1).
This oscillator can be any DIL Quartz oscillator up to 16 Mhz or a simple RC oscillator made from
a couple inverters (Cmos or TTL) and 2 resistors and 1 capacitor. Schematic diagram can be found in the Internet.
I don't think that changing of the SUT (StartUpTime) will affect the programming.

The reason that your LCD module did not work can be related to a wrong LCD contrast voltage on pin 3 (VEE)
of the LCD module. Normally this voltage is between 0 and +5 volt, but some LCD modules needs a negative
voltage up to -10 volt. If the contrast voltage is wrong, then you won't see anything happening on the display.

Dolf de Waal
----- Original Message -----
From: made sadwuri
To: a...
Sent: Wednesday, July 25, 2007 4:05 AM
Subject: [AVR club] my problem
hi all..
I am a beginner in microcontroler,i have a problem in programming microcontroller ATmega8535. I hope any one could help me..
I want to integrate LCD module to my ATmega 8535..according to literature, it should be set security and configuration bit first
on ponyprog. And i do that..but my LCD still doesn't work, so i change the set security and configuration bit (SUT and CKSEL)..
and accidentally my ATmega couldn't be downloaded anymore, there's comment "unknown device (24)".
I am so sad because it has happened 3 times, i mean i have broken 3 microcontroller.
is my atmega broken? could it be repaired?
i really need your help to solve my problem.
thanks so much.

________________________________________________________
Kunjungi halaman depan Yahoo! Indonesia yang baru!
http://id.yahoo.com/



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I had the exact same problem with the same chip. For some reason
PonyProg INVERTS the fuse bits for OSC selection. If it doesn't work
with a standard crystal oscillator setup, you have to (as someone
already mentioned) supply the chip with some kind of input to the
clock input.

In my case I had several old AT90S2313 chips, so I connected them
normally (they require an external osc) and then connected the CLK
output of the AT90S2313 to the clock input of the mega8545.

You could also use a 555 timer, you could write a quick program to
turn on/off a pin of another (working) 8535 and use that as the clock
source.

--- In a..., made sadwuri wrote:
>
> hi all..
> I am a beginner in microcontroler,i have a problem in programming
microcontroller ATmega8535. I hope any one could help me..
> I want to integrate LCD module to my ATmega 8535..according to
literature, it should be set security and configuration bit first
> on ponyprog. And i do that..but my LCD still doesn't work, so i
change the set security and configuration bit (SUT and CKSEL)..
> and accidentally my ATmega couldn't be downloaded anymore, there's
comment "unknown device (24)".
> I am so sad because it has happened 3 times, i mean i have broken 3
microcontroller.
> is my atmega broken? could it be repaired?
> i really need your help to solve my problem.
> thanks so much.
>
> ________________________________________________________
> Kunjungi halaman depan Yahoo! Indonesia yang baru!
> http://id.yahoo.com/
>
>
>