# AVR-MT-128 Serial Comm to PC not working **URL:** \ **Category:** MicroMod\ **Tags:** avr-atmel\ **Created:** [July 24, 2005, 4:37am UTC](https://community.sparkfun.com/t/avr-mt-128-serial-comm-to-pc-not-working/758 "2005-07-24T04:37:42Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![twoba](https://avatars.discourse-cdn.com/v4/letter/t/57b2e6/32.png) [@twoba](https://community.sparkfun.com/u/twoba)\ **Post date:** [July 24, 2005, 4:37am UTC](https://community.sparkfun.com/t/avr-mt-128-serial-comm-to-pc-not-working/758/1 "2005-07-24T04:37:42Z")
I am running the example code that comes with the AVR-MT-128 but I can’t get the serial connection to my PC to work right. When I hookup a com port on my PC to the AVR-MT-128 DB9 I type on my PC keyboard and see strange characters on the AVR-MT-128 display. Likewise when I click the B5 button, the LCD says “sending to RS232” but my terminal app on my PC shows strange non-alphanumeric characters. I am sure that there is an easy answer to this. Does anyone know what the correct serial port settings are for a terminal emulator to talk to the AVR-MT-128? By the way, I have tried Hyperterminal, the terminal emulator that comes with Bascom and MTTTY using all baud rates and different handshake, RTS settings but they all show unreadable characters. ---
**Author:** ![murphyr](https://avatars.discourse-cdn.com/v4/letter/m/858c86/32.png) [@murphyr](https://community.sparkfun.com/u/murphyr)\ **Post date:** [July 24, 2005, 1:37pm UTC](https://community.sparkfun.com/t/avr-mt-128-serial-comm-to-pc-not-working/758/2 "2005-07-24T13:37:56Z")
Confirm that your AVR-MT-128 is using the clock source that you think it is using (confirm by reading fuses or write a blinky program to blink a led at 1 Hz) Usually you need 8 bit, no parity, 1 stop bit, no flow control, probably at 9600 (but you need to confirm this in the code) ---
**Author:** ![twoba](https://avatars.discourse-cdn.com/v4/letter/t/57b2e6/32.png) [@twoba](https://community.sparkfun.com/u/twoba)\ **Post date:** [July 25, 2005, 12:43pm UTC](https://community.sparkfun.com/t/avr-mt-128-serial-comm-to-pc-not-working/758/3 "2005-07-25T12:43:16Z")
Thanks, I tried setting the fuses as suggested on this page: [http://www.frankvh.com/mp3player/avrprog.htm](http://www.frankvh.com/mp3player/avrprog.htm). This worked once, but after that, my PonyProg tells me “Device missing or unknown device (-24)” when I tried to tweak the fuses again. Is there a way to reset the fuses so the PonyProg can read and write them again? By the way, before I had the fuse problem I wrote a led blinky program and it blinked pretty close to every second. ---
**Author:** ![twoba](https://avatars.discourse-cdn.com/v4/letter/t/57b2e6/32.png) [@twoba](https://community.sparkfun.com/u/twoba)\ **Post date:** [July 27, 2005, 1:58am UTC](https://community.sparkfun.com/t/avr-mt-128-serial-comm-to-pc-not-working/758/4 "2005-07-27T01:58:09Z")
Ok, I think I accidentally screwed up my avr-mt-128 board. When I read the Configuration and Security Bits, PonyProg tells me that all of them are programmed, including the lock bits. One website I found said to erase the flash, but the erase function fails with the same “Device missing or unknown device (-24)” message. Anyone have a suggestion on how I can reset or unprogram the lock/security bits and fuses? ---
**Author:** ![murphyr](https://avatars.discourse-cdn.com/v4/letter/m/858c86/32.png) [@murphyr](https://community.sparkfun.com/u/murphyr)\ **Post date:** [July 27, 2005, 2:53am UTC](https://community.sparkfun.com/t/avr-mt-128-serial-comm-to-pc-not-working/758/5 "2005-07-27T02:53:45Z")
It sounds like you may have set the clock fuses incorrectly. Check out [avrfreaks.net](http://avrfreaks.net), search the forums for “dead AVRâ€