Serial eeprom programmer question

Hardware questions and issues with the FV-1

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sajy_ho
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Joined: Wed Apr 15, 2015 5:40 am

Serial eeprom programmer question

Post by sajy_ho »

Hi, I've recently built a guitar pedal based on FV-1 and I'm using this serial programmer to program the EEPROM:http://www.hqew.net/files/Images/Articl ... serial.gif
I want to use pedal's supply(3.3V) insted off 5V regulator and use this circuit as on-board programmer; So I don't have to open the box and remove the eeprom every time I need to program it.
My problem is those 5V1 zeners, do I need to replace them with 3V3 zeners to use this circuit to program the eeprom on the same board with the FV-1? Will use of 5V1 zeners damage the FV-1 or it just doesn't care?
Thanks
Sajad
frank
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Post by frank »

FV-1 is a 3.3V only device so you cannot connect a 5V programmer to it to program the EEPROM, that will destroy the FV-1. You will need to contact the designer of the programmer you referenced to learn how to modify it for 3.3V operation as that is outside the scope of this forum.
Frank Thomson
Experimental Noize
sajy_ho
Posts: 9
Joined: Wed Apr 15, 2015 5:40 am

Post by sajy_ho »

Thank you Frank for the answer, So I'll probably give up the onboard programming and settle on removing the eeprom from its sucket, because I fried a FV-1 during soldering and don't want to lose another one!
Thanks again
Sajad
slacker
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Joined: Tue Feb 01, 2011 1:13 pm

Post by slacker »

Even if you used 3.3 Volt Zeners the FV-1 could still be damaged, the peak voltage could still exceed 3.3Volts. You could use the circuit I posted over on diystompboxes instead http://www.diystompboxes.com/smfforum/i ... #msg994174 it is safe with 5 Volts or larger signals on the the inputs, the FV-1 only ever sees 3.3 Volts.
sajy_ho
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Joined: Wed Apr 15, 2015 5:40 am

Post by sajy_ho »

Hi Ian, I was hoping to see you here, I built that circuit but unfortunately it didn't work for me either with ic-prog or with pony prog; The only circuit that I could get to work was the one I posted above. I will try your circuit once again and see if it workes.
Thanks
slacker
Posts: 116
Joined: Tue Feb 01, 2011 1:13 pm

Post by slacker »

It could be your ic-prog settings are wrong. For my programmer in Settings/Hardware you need to select "JDM programmer" as the programmer and tick "Invert Data Out" and "Invert Clock"
sajy_ho
Posts: 9
Joined: Wed Apr 15, 2015 5:40 am

Post by sajy_ho »

Ohhh you're right; those transistors are inverting the pulses.Thanks Ian, I'll give it another try.
Also could it be the layout causing this problem? I mean I'm using perfboard, and the ic orog acts like there isn't any programmer connected...
Thanks
Sajad
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