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techknight
Joined: 21 Apr 2008
Posts: 231
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 Posted: Wed Feb 05, 2020 9:15 pm Post subject: |
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Thanks for the tips. Grounds are secure, all that is fine.
Turns out, out of the 4, I got 2 working again so far. the SP724 TVS diode shorts out.
Removed them, and the light turns green.
However, the 3rd one I have is the slightly newer one, 2012 instead of the 2009, which made no difference. Shows red, connecting the cable, and it flashes orange. So something else is wrong internally with that one.
the 4th one is shottky rigged to 5V so I cant try that one. But it faced a similar issue, only the RESET section of the TVS diode was nearly 200 ohms to ground (shorted internally). |
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jenalcom
Joined: 10 Apr 2004
Posts: 365
Location: Perth, Western Australia
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| Posted: Sat Feb 08, 2020 2:07 pm Post subject: |
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Thanks for the tips. Grounds are secure, all that is fine.
Hopefully you tested the grounds when the programmer and the target were NOT connected together ! |
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techknight
Joined: 21 Apr 2008
Posts: 231
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| Posted: Sat Feb 08, 2020 2:51 pm Post subject: |
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That doesnt even make sense to test for that, as then the two grounds are not connected together.
They arnt together until you plug the programmer into the board.
as far as voltage being on the ground, there wouldn't be because its physically DC Ground on the board. programmer, I have no idea. Could be USB ground I suppose? |
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jenalcom
Joined: 10 Apr 2004
Posts: 365
Location: Perth, Western Australia
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| Posted: Sun Feb 09, 2020 4:37 am Post subject: |
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We call the ground rail ground for convenience. It doesn't mean that it is actually at a certain potential. The two grounds can be at different potentials (due to power supply problems/leakages/floating) however when you connect them together (ie plug in the progarammer) then they are at the same potential (physically connected).
The problem is that if one 'ground' is actually at ground and the other is 'floating' at say 100v then there is a potential difference until you connect the two together. If say, when plugging in the programmer to the board, one of the other lines gets connected first then that line instead of having say just 5v on it could have 105v on it (with reference to the ground of the other unit). And that will definitely cause problems!
It is always 'good practice' to ensure that the grounds are connected together first before any other connections are made. |
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Madf
Joined: 13 Nov 2011
Posts: 179
Location: Moscow
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| Posted: Thu Jun 18, 2020 7:47 am Post subject: |
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| EDC wrote: | I think Im the hardcore when I watch yours MKII ahahahaha. For what so many parts on them? Maybe they are also debuger?
I build myown MKII years ago. Have spare uC and GTL2003 buffer but this programmer never fail!
Works extremely fast with Bascom and newest Studio 7 with "one click change".
Ive even eatch this PCB  It use only AT90USB162 and GTL2003. Program is flashed via its own USB and bulit in bootloader FLIP.
Firmware is latest LUFA. PCB and design is not my project but if anyone interrested I can attach whole 1.4MB project with PCB's.
I have newest ICE but this programmer is my favoured one for Xmegas |
Hello everyone.
An interesting topic, the scheme you posted, thanks.
Can you post instructions for flashing the chip and the firmware itself?
Or give a link (where to read). |
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