[En-Nut-Discussion] Could not enter programming mode

[Daniel]

Daniel schrieb:
> Daniel wrote:
>
>   
>> Andre Riesberg schrieb:
>>  
>>
>>     
>>> Daniel wrote:
>>>
>>>  
>>>    
>>>
>>>       
>>>> Hi.
>>>>
>>>> While I was programming my Ethernut 1.3 with stk500.exe, I had 
>>>> connected SCK (SPI Bus Serial Clock) to GND. After that I read, that 
>>>> I must not do that.
>>>> Now stk500.exe tells me, that the controller "Could not enter 
>>>> programming mode".
>>>>
>>>> Any advise how to fix it up?
>>>>
>>>> Thanks,
>>>> Daniel
>>>> _______________________________________________
>>>> http://lists.egnite.de/mailman/listinfo/en-nut-discussion
>>>>
>>>>
>>>>
>>>>
>>>>    
>>>>      
>>>>
>>>>         
>>> Hi Daniel,
>>>
>>> do you pull the SCK signal to GND only on the programmer or on cpu or 
>>> on both?
>>>
>>> Do you have disconnected all power supplys and start again?
>>>
>>> Please make some tests:
>>> First, disconnect programmer and CPU.
>>>
>>> - Check the SCK signal at the programmer: In normal condition (no
>>> programming) the signal must be on high level.
>>> - Check the SCK signal at the CPU board. Normally you see a low level. 
>>> With a 10k resistor to +5V you can pull this signal to high level.
>>> - With still disconnected board try to start programming (I use 
>>> avrdude). With a scope you can see (for a short time) a lot of pulse 
>>> on the SCK line.
>>>
>>> Does this work?
>>>
>>> Greeting
>>> Andre
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> http://lists.egnite.de/mailman/listinfo/en-nut-discussion
>>>
>>>  
>>>    
>>>
>>>       
>> Hi Andre, thanks for the answer.
>>
>> Here are the results of the tests you mentioned:
>>
>> - SP Duo 2 Programmer, only supported with Vcc & GND, not connected to
>> CPU: SCK (PB1) is low
>>    When I start programming, I see a short low voltage at SCK. 
>> Unfortunately I doesn't have a scope, only a voltmeter.
>>    You say, the signal must be on high level. It's low. But I can 
>> program my second Ethernut with this SP Duo without problems.
>>
>> - CPU, not connected with SP Duo 2: SCK (PB1) is low
>>    Should I try to pull the SCK line high, when I connect the 
>> programmer to the CPU?
>>
>>
>> Daniel
>> _______________________________________________
>> http://lists.egnite.de/mailman/listinfo/en-nut-discussion
>>
>>
>>  
>>
>>     
> Hi Daniel,
>
> see my commends:
>
> - SP Duo 2 Programmer, only supported with Vcc & GND, not connected to
> CPU: SCK (PB1) is low
> ** Could be ok. I have no schematics from this programmer.
>     When I start programming, I see a short low voltage at SCK. 
> Unfortunately I doesn't have a scope, only a voltmeter.
> ** That's makes it a little complicated......
>     You say, the signal must be on high level. It's low. But I can program
> my second Ethernut with this SP Duo without problems.
> ** Ok. I think the programmer is no defect.
>
> - CPU, not connected with SP Duo 2: SCK (PB1) is low
>     Should I try to pull the SCK line high, when I connect the
> ** Try it with 10k! You have a second board, try to compare the signals on
> the two board.
>
> programmer to the CPU?
>
> Greetings
> Andre
>
>
>
>
>
> _______________________________________________
> http://lists.egnite.de/mailman/listinfo/en-nut-discussion
>
> Hi Andre,
>
> Both Ethernuts have a low SCK line. Both programmers I've tested have a low
> SCK line. One Board and both programmers work. Only on one board, the
> programmer cannot enter the programming mode.
> Even with SCK, pulled to high via 10k it doesn't work.
>
> Daniel
>
> _______________________________________________
> http://lists.egnite.de/mailman/listinfo/en-nut-discussion
>
>   

Hello again.

Any hints what to do now? Is the board broken? Should I send it back to 
egnite?

Daniel