Hi everyone!
So, as I make more use of the QL-SD on my BBQL, I decided to re-wire the MDV2 (red) LED to the QL-SD daughter-card, in place of the pink LED pre-soldered to the daughter-board.
However, even after carefully checking polarity and checking the LED itself was still working, the MDV LED refuses to light-up at all upon SD access.
I'm suspecting a lower voltage on the SD-Card daughter-board or something similar.
Any ideas?
Switching the LED on the QL-SD...
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- Aurora
- Posts: 924
- Joined: Sat Oct 25, 2014 9:53 am
Re: Switching the LED on the QL-SD...
Martyn,
actually, nearly everything on the the QL-SD runs at 3.3V - Including the LED.
Are you sure there's no left-over resistor anywhere in the QL circuitry?
You might want to have a look at the attached schematic to make sure you got it right.....
Tobias
actually, nearly everything on the the QL-SD runs at 3.3V - Including the LED.
Are you sure there's no left-over resistor anywhere in the QL circuitry?
You might want to have a look at the attached schematic to make sure you got it right.....
Tobias
ʎɐqǝ ɯoɹɟ ǝq oʇ ƃuᴉoƃ ʇou sᴉ pɹɐoqʎǝʞ ʇxǝu ʎɯ 'ɹɐǝp ɥO
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- Aurora
- Posts: 924
- Joined: Sat Oct 25, 2014 9:53 am
Re: Switching the LED on the QL-SD...
Aha!
Thank you Tobias - if only I had checked the schematic first!
I had thought I'd measured one leg of the LED at GND, (the other end connected to the limiting resistor), and hence oriented my (ex MDV) LED accordingly.
I see now that the LED is fitted between +3.3v and the limiting resistor (then to GND).
I'll reverse the orientation and try again.
Glad I asked!
M.
Thank you Tobias - if only I had checked the schematic first!
I had thought I'd measured one leg of the LED at GND, (the other end connected to the limiting resistor), and hence oriented my (ex MDV) LED accordingly.
I see now that the LED is fitted between +3.3v and the limiting resistor (then to GND).
I'll reverse the orientation and try again.
Glad I asked!
M.
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- Aurora
- Posts: 924
- Joined: Sat Oct 25, 2014 9:53 am
Re: Switching the LED on the QL-SD...
Hi Tobias
Just to close the loop - yes, simply reversing my (mistaken) connection to the LED resolved the issue!
I must remember to RTFM in future!
M.
Just to close the loop - yes, simply reversing my (mistaken) connection to the LED resolved the issue!
I must remember to RTFM in future!
M.