Device not recognised...

General discussion on mikroC for dsPIC30/33 and PIC24.
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Sobrietytest
Posts: 619
Joined: 05 Jul 2008 06:05
Location: Thailand

Device not recognised...

#1 Post by Sobrietytest » 13 Dec 2008 02:31

I have a completed program which works fine on the LV24-33A using a PIC24FJ96GA010. I then had PCB's made up, I populated the first one and tried to program the chip using the LV2433 programmer (powered from USB with the correct jumper settings), this gave me the 'Device not recognised' error. I have double checked all the PCB layout, voltages, MCLR and program pins - everything is correct.

I then placed a second chip onto a new PCB with just the regulators and programming header without any peripherals (RTC, SD, MAX232, ADIS16203), double checked everything and I still got the same result - 'Device not recognised'. Just to be certain I did the same with a third board with the same result.

Then I started thinking it was maybe a problem with the programmer so I hotwired the power and programming pins from the dev board onto my PCB - same result.

Can anyone give me some idea what's going wrong? The chips are from a reputable supplier and they were all factory packaged, I have plenty of experience soldering this type of chip and they all have the industrial temperature tolerance. I have a sneaky feeling that this might be a software/configuration issue. Any help greatly appreciated.
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rmteo
Posts: 1330
Joined: 19 Oct 2006 17:46
Location: Colorado, USA

#2 Post by rmteo » 13 Dec 2008 03:08

How have you set up the voltage regulator of the PIC? If it is enabled, do you have a low ESR cap (4.7-10uF) on the VCAP pin connected to GND? See section 23.2 of the datasheet.
Why pay for overpriced toys when you can have
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rmteo
Posts: 1330
Joined: 19 Oct 2006 17:46
Location: Colorado, USA

#3 Post by rmteo » 15 Dec 2008 17:36

Were you able to resolve this issue?
Why pay for overpriced toys when you can have
professional grade tools for FREE!!! :D :D :D
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Sobrietytest
Posts: 619
Joined: 05 Jul 2008 06:05
Location: Thailand

#4 Post by Sobrietytest » 16 Dec 2008 11:41

Sorry rmteo, I've been tangled up in another project - and an ISO audit! :(

I've asked one of my techs to check it but he didn't get back to me yet. I'll hopefully have an answer by the weekend but I'm sure that you are right; I wasn't aware of the reduced core voltage.

I guess we may have blown a couple of chips then! :roll:
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Sobrietytest
Posts: 619
Joined: 05 Jul 2008 06:05
Location: Thailand

#5 Post by Sobrietytest » 18 Dec 2008 11:34

Just an update...

The capacitor on VDDCORE was present but the ENVREG was sent to GND - not 3.3v. So after some cut-and-splice I was able to program the PIC. Thanks very much for the heads-up rmteo.

:D

However, I identified a further 9 errors on the PCB caused by the manufacturer! Having rechecked our Gerbers, they were actually altered by the manufacturer as part of their 'quality control'. Needless to say, we won't be using them again.

Thanks again.
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