SparkFun Forums

[cpolley]

Right, my mistake, it looks like you are giving an external supply.

It might well be your programmer, but the things to try before deciding that are:

1) Double check that you have made the right connections to your programmer - are you sure you don't have the pins reversed?

2) Make sure (with a multimeter) that when you power it up:
There is definitely 5V between the VCC and ground pin
The reset pin is held high (5V)

3) Since you already have AVRstudio set up, simpler than programming the chip is trying to read the signature byte from it and making sure it matches a mega8.

4) If you have another mega8 try with that. From the factory they come configured for their internal oscillator, but if you've somehow changed the fuse bits it will cease to function without a crystal

5) If you put LEDs on the MOSI/MISO/SCK pins (with ~500ohm resistors of course) you should see them flicker when the programmer tries to connect. In the absence of a logic analyser this is one way to see if the programmer is at least TRYING to talk to your chip.

Good luck =)

[bryank]

appreciate it big time! i will be sure to try this tomorrow morning, thank you so much!

[bryank]

1) Double check that you have made the right connections to your programmer - are you sure you don't have the pins reversed?

ALL CHECKS OUT TO BE GOOD

2) Make sure (with a multimeter) that when you power it up:
There is definitely 5V between the VCC and ground pin
The reset pin is held high (5V)

5V EVERYWHERE, 2.5V ON RESET PIN WITH 10K PULLUP RESISTOR, TRIED BY REMOVING RESISTOR AS WELL SO CHIP SAW 5V

3) Since you already have AVRstudio set up, simpler than programming the chip is trying to read the signature byte from it and making sure it matches a mega8.

I GET A SIGNATURE NOT READ RESPONSE

4) If you have another mega8 try with that. From the factory they come configured for their internal oscillator, but if you've somehow changed the fuse bits it will cease to function without a crystal

I HAVE TRIED 4 OTHER CHIPS

5) If you put LEDs on the MOSI/MISO/SCK pins (with ~500ohm resistors of course) you should see them flicker when the programmer tries to connect. In the absence of a logic analyser this is one way to see if the programmer is at least TRYING to talk to your chip.

LEDs DO NOT BLINK, MUST BE THE PROGRAMMER???

[theatrus]

5V EVERYWHERE, 2.5V ON RESET PIN WITH 10K PULLUP RESISTOR, TRIED BY REMOVING RESISTOR AS WELL SO CHIP SAW 5V

You should have 5V on the reset pin with pullup in place. Is this with the programmer connected or disconnected? Are you 1000000% sure you're counting PIN 1 of the programming header correctly?

[bryank]

built a new programmer based on this website HERE

It too doesn't work on 2 computers, both with lpt1 ports configured to everything under the sun.

Im 1000000000000000000% sure I have the programmer wired correctly, you can check the pictures on the first page and see so.

When I hook LEDs up to SCK MISO MOSI NOTHING blinks when I try to connect, they just stay on.

I have simply jumped to reset pin to VCC for the time being so to avoid any errors with a switch/resistor/etc.

Anymore ideas before I pay someone to breadboard 2 circuits for me and overnight ship them as this is for a client's project. Thanks for all of your help thus far

[stevech]

Don't use parallel port programmers. Notoriously unreliable and incompatible with PC OS.

use a pre-programmed AVR with a serial port bootloader. Or get someone to program one into chips you have. PM me and I'll do so.

Or buy a preprogrammed chip w/serial bootloader. Or pre-programmed with a full virtual machine - such as zbasic.net's modules/chips.

Best bet: Purchase an Atmel ISP for USB.

[bryank]

That's exactly what I am doing now, shelling out bigger bucks for a USB programmer. Ill be sure to let you know if that cures my problems

[theatrus]

Buy an Atmel ISP mk2. The official version is the only way to go

Your reset voltage is still concerning.

[n1ist]

I would get a real programmer such as the AVRISP2 or AVR Dragon. They are not too expensive, USB based, and really work, unlike many of the hack jobs...
/mike

[bryank]

yep just bought a AVRISP2 from digi. Will have it by thursday, wish me luck!

[cpolley]

Well, good luck! Unfortunately, as a rule the fastest way to solve a problem is to spend money on it.

Also: Don't connect your reset pin directly to VCC, or your programmer won't be able to pull it low when it needs to. Use a single 5 - 10kohm resistor between reset and VCC.

And 2.5V on the reset pin is definitely not right. While you're waiting for your new programmer try to sort that out on your breadboard.

[Applekid]

Silly observation, but, are you sure the button on the breadboard is not accidentally rotated 90 degrees? I bought the kit from SFE but I've never been happy with how badly it fits in the breadboard and it's real easy to put in wrong or with a bad connection.

[bryank]

HURRAY it works! The new AVRISP mkII programmer kicks that stupid parallel port programmer's butt! Worked first try with the exact same circuit I had been trying to program for the past week. Thanks for your help guys!

[walkert1]

I am having the same issue with my used atmega168. I am working with one of Ocean Controls DC motor PID speed controllers and I would like to customize the application (which they allow but I have yet to get myself up to speed). I am using a usb avrisp on com 3. I've made several attempts and it will never enter program mode. The atmega168 was previously used and I am wondering if it is locked(protected) because of the programming that it contains from Ocean Controls. My board is the one created through the SFE tutorials (http://www.sparkfun.com/commerce/tutori ... ials_id=93).
Is it possible that the chip is locked? I am very new to this.

[stevech]

Ask Ocean Controls?