AVR Freaks

Aah I say.

Thanks guys, I now see 2 potential problems.

#1 is I programmed the device first then tried to start debugging. So that's wrong eh ? Just build the program, then go straight to "Start debug and break". I would never have guessed that. So that means the debug session must actually program the code into the AVR automatically. I'm sure I didn't see any such instructions in the Atmel-ICE user guide.

#2 is I am actually using an Uno board to do this. I'll look into that RESET-EN solder bridge and anything else in the circuit. Might be better off doing this on a breadboard for now just to be sure.

I'm trying to "unbrick" the AVR with HV programming on my STK500, then I find out it isn't being recognised in Atmel Studio 6.2 (it worked before). Later on I tried AVR Studio 4.19 and I can get my STK500 to show up so seems there's some problem with AS 6.2

Cheers,

Keith.

I seen the 10K pullup in the Uno schematic and thought the debugwire would simply pull that low, like what happens in many circuits. If that's not the case I didn't know.

I've got no problems with the opening/closing of a solder bridge. I design my own circuit boards, cnc drill them on my self built cnc plasma table, then solder all the components in. So I'm certainly not frightened of opening up a solder bridge. Especially easy with my Hakko 808

How can I obey rules if I don't know what they are in the first place. That's what I said in my first post, the lack of clear instructions on HOW. Instead I have to try and guess at what to do.

Your statement is also implying I'm complaining about the debugwire system when I'm complaining about Atmel not giving clear instructions on how to use it. I'm not the only one who goes through confusion with this one. I bought the Atmel-ICE mainly for the debugging and I'll be extremely happy and excited when I get it working. I don't need to think about it, already did that before I bought it, and ended up thinking that will be awesome.

Keith.

The clone I was using is a "DK" type from China, it doesn't seem to have any RESET-EN and not sure where that cap will be. The other one is a FREETRONICS brand and it has it clearly labelled. Might get a board to dedicate to this programming / debugging task.

Just managed to reset the DWEN fuse with high voltage programming on the oldie STK500. I now have a new love for that old board. I stuffed up my previous attempts to do that because I didn't have a single wire connector in place BSEL2 to PC2. One ATMEGA unbricked.

John you are dead right. Amongst the other things I was doing wrong that was one of them. 

Time to attempt debugwire again.

Keith.

Cheers Dave,

I'll do that, plenty of them on Ebay.

John, any reason why you don't use the Atmel-ICE (buried deep inside some cupboard). Do you have some other preferred debugger ?

Well, success, got debugwire working (YIPPEE), AND..........

Failure.

The breakpoints which work perfect in the simulator don't work the same in debugwire.

I've got two Timer 2 interrups, one for compare and one for overflow. I have breakpoints at the first line of code in each ISR. The code stops at the compare ISR but not at the overflow ISR. I tried to find some info and am wondering if I need to do run to cursor instead of setting breakpoints the same as the simulator.

I'll continure debugging the debugger when I get in from work tonight. I see there's also a tickbox for halting the timer when code is stopped. I'll have to play with that one too.

Keith.

Well well well, look what I found, exactly the same problem:

https://www.avrfreaks.net/forum/ice-mega328-breakpoint-isr-not-being-hit?skey=debugwire

Hopefully that's where my problem lies (bug in the debugger LOL ???).

Thanks again lads,

Keith.

Thanks David,

good point about code being optimised out. I'm still trying to get that one concreted in my head.

This particular code could not have been optimised out:

ISR (TIMER2_OVF_vect)
  {
	T2_OVERFLOW = TRUE;
  }  

FALSE is 0 (zero) and TRUE is 1

T2_OVERFLOW is FALSE before this ISR so the compiler can't get rid of that instruction.

The code works perfectly in the simulator and I have a watch window for the T2_OVERFLOW variable, and see it change from 0 to 1 after the T2_OVERFLOW = TRUE instruction

In the other thread I think the guy had the very same debugwire problem (timer OF interrupt ISR) and he put the breakpoint at the "{" before, and everything worked.

I've just got out of bed and will try it after brekky.

Keith.