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Serial eeprom programmer question
Posted: Sat Apr 25, 2015 6:05 am
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
Posted: Sat Apr 25, 2015 10:10 am
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.
Posted: Sat Apr 25, 2015 1:30 pm
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
Posted: Mon Apr 27, 2015 10:00 am
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.
Posted: Mon Apr 27, 2015 1:18 pm
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
Posted: Wed Apr 29, 2015 10:36 am
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"
Posted: Sat May 02, 2015 12:19 am
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
