Thursday, April 21, 2011

PSoC 3 - Unrecognized USB Device

Update - It Works!

A rude shock,when i plugged the board back in,between trying to play around with the POV Example,the FTK showed up as an unrecognized USB device.My "Redo" instincts kicked in,and I reinstalled the software(drivers,creator,programmer,..the whole deal).Still no luck.Calming down,I took the problem piece by piece.Cable,Board,PC.Dug out a cable that came with my TI MSP430 Launchpad board,..still the yellow exclamation sign,bearing the grim message.To eliminate the PC,i did the whole install on a friend's VAIO,but the kit refused to co-operate.
Throughout all this,i did notice that the kit was getting power.

A discussion I had with tinman(from the PSoCDeveloper forums) some time ago,did give me a clear picture of what the board had.The PSoC3 chip,the FX2 chip and an EEPROM with a proper USB id,apart from the power circuity and the sensors,capsense,LEDs etc.

Since the power comes on,and the LEDs+Accelero work(POV Display),that section seems ok.Since the PSoC itself is driving them,I'd give it a green too.The shadow of doubt is on the FX2 and the EEPROM. Is it the EEPROM? Did the FX2 chip face sudden death?

Ive opened this to discussion on the PSoCDeveloper forums(here).I pray the kit isnt dead.I was just beginning to love it :'(

Update - 22-04-11 :Is it the EEPROM? In USB designs,this kind of problem is attributed to zeroed values of VID and PID,which in our case are on the EEPROM,a really tiny SMD part at that,making replacement(after reprogamming the VID,PID into the replacement part) impossible without a hot air rework station.

Update - 23-04-11 : As suggested by undesh of the PSoCDeveloper forums,I'll try sniffing the USB traffic to see what goes on.

Update - 25-04-11 : USB traffic,shows no response.Is the chip off? I pull out my trusty multimeter,and the schematics for the FTK.All the places that are supposed to be 3.3V,are 2.4V.The ZLD 0330's Vout,the FX2's Vcc-s,EEPROM Vcc etc. That doesnt look right,but I am no CyPro.I'll head off to bed,4am in the morning.

Update - 25-04-11 : I touch the probes from my LM317 based 3.3v supply to pins 5(Vout) and 7(Gnd) on the ZLD,and reinsert the USB cable,and Bingo!..We are back! :) ..the FTK3 comes up.Looks if like i'll wire in my own 3.3v regulator,then will be able to use it again. :) Thank You God. Rebirth!!

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