Author Topic: device failure on PICKIT2 (Read 22911 times)

Simon · « **Reply #25 on:** October 20, 2012, 05:38:02 pm »

Quote from: djsb on October 20, 2012, 05:33:23 pm

Please be more specific. What is "it"? Did you put the 10k resistor on the MCLR pin? Which pins on the Pickit 3 are connected to which pins on the device. Do you get any message at all in MPLAB? What configuration fuses are you using (are they in your source code listing or set up in MPLAB?Have you tried powering the target from a separate supply and not the Pickit?

David.

Well tried a 1K to no avail, I'll dig out a 10K and retry. but I repeat I have never had these issues until now, other day worked fine.

Simon · « **Reply #26 on:** October 20, 2012, 05:39:25 pm »

I keep getting "no device detected"

I thought MCLR is a function of the pic in operation not programming, it just happens to be multiplexed with the Vpp

Jon Chandler · « **Reply #27 on:** October 20, 2012, 05:41:24 pm »

By the way, is your PICkit 2 "the real deal" from Microchip or a clone?

Some of the clones are very good, some skimp on the details. One area people get into trouble is programming 3 volts parts. Some of the clones left out the circuitry to control Vdd. Changing it in the GUI doesn't actually change the voltage supplied.

djsb · « **Reply #28 on:** October 20, 2012, 05:46:53 pm »

Which pins on your Pickit 2 are connected to which pins on your device?

Simon · « **Reply #29 on:** October 20, 2012, 05:47:35 pm »

it's a genuine one, one of those advertised at £17.50 and costing £35 by the time it got vat on, packed, shipped, shipping extra charge bla bla. I've hardly used it really.

Still no luck with a 10K resistor and programming in situ. I can read it but am getting: "programming failed at program memory address 0x000000"

This is on a 16F883, I'm totally pissed off, I'm supposed to be writing C code not trying to make a stupidly expensive programmer work.

I'll try re installing the firmware on the pickit although it is up to date !

Simon · « **Reply #30 on:** October 20, 2012, 05:49:30 pm »

Quote from: djsb on October 20, 2012, 05:46:53 pm

Which pins on your Pickit 2 are connected to which pins on your device?

16F883

pickit1 to pin 1
pickit2 to pin 20
pickit3 to pin 8
pickit4 to pin 28
pickit5 to pin 27

djsb · « **Reply #31 on:** October 20, 2012, 05:50:52 pm »

Put on an anti-static strap and fit a new chip.

David.

Simon · « **Reply #32 on:** October 20, 2012, 05:55:10 pm »

I just tried to reflash the pickit firmware and it failed, I now have no more pickit2 until i reload it. But this seems to point at USB communication now. could it be because it's plugged into a USB hub ?

I don't have an antistatic strap and to be honest I've treated pics far worse and they have been fine.

djsb · « **Reply #33 on:** October 20, 2012, 06:00:24 pm »

Yes, just try it without the hub. Your connections check out fine (sorry had to ask for confirmation). Sometimes the usb driver needs to re enumerate so removing/replugging it in seems to help.

David.

Jon Chandler · « **Reply #34 on:** October 20, 2012, 06:00:44 pm »

I have never gotten my PICkit to work reliably on a more-than-four port hub.

Also, using a non- powered hub has lead to problems too.

If the PIC has multiple power and ground pins, all must be connected.

Simon · « **Reply #35 on:** October 20, 2012, 06:02:46 pm »

Quote from: Jon Chandler on October 20, 2012, 06:00:44 pm

If the PIC has multiple power and ground pins, all must be connected.

oh ?

I'm getting no luck plugged into the pc's from USB port, and i mean after all every port on a PC is coming off a 2 port hub isn't it ?

djsb · « **Reply #36 on:** October 20, 2012, 06:02:54 pm »

Yes, I noticed that there are 2 VSS pins on the 883 (pins 8 and 19). Are they both connected to ground?

David.

Simon · « **Reply #37 on:** October 20, 2012, 06:05:13 pm »

just tried it with both connected, no joy, I'm also getting ever more pissed off with the pickit program enabling code protection just to complicate matters. It never used to do that either, what the hell is going on

Simon · « **Reply #38 on:** October 20, 2012, 06:07:03 pm »

um, remind me: an antistatic strap amounts to a piece of bare wire wrapped around my wrist and connected to the earth pin in a plug ? I can sort one of those. Do i need one for each hand or will one do ?

djsb · « **Reply #39 on:** October 20, 2012, 06:07:51 pm »

Device on it's last legs. Try a new one. Have a break and start again. If all else fails send it to me in a jiffy bag and I'll program it for you.

David.

djsb · « **Reply #40 on:** October 20, 2012, 06:09:24 pm »

Just one strap (with built in isolation resistor) is all that's needed.

David.

Simon · « **Reply #41 on:** October 20, 2012, 06:09:53 pm »

erm it's my first attempt at programming it and it is brand new, arrived yesterday. Yesterday all worked fine. now a total mystery. if you PM me your address I'll pop one of the offenders in the post and you can give it a go.

Simon · « **Reply #42 on:** October 20, 2012, 06:43:05 pm »

Well just tried getting a new chip out with a strap on (bar wire around wrist of hand dealing with chip connected to the earth pin of a mains plug via a 10K resistor). same lack of a result. I started to get this with my well used 16F88 chips as well and assumed I'd been over abusing the chips, now I think they might have been ok.

I'll post some off to David Monday for him to try.

JVR · « **Reply #43 on:** October 22, 2012, 09:12:47 am »

Check P208 of the 883 datasheet, did you do anything with the LVP bit?

the 16F88X's are picky to get working, so make sure you give it proper 5V, decoupled, and leave the programming utility alone, program directly from MPLAB.

Also, test the programmer with another micro, that will verify that it is not blown. As mine (7yrs old) had blown a mosfet or two during its life.

Simon · « **Reply #44 on:** October 22, 2012, 09:15:50 am »

I've ordered a pickit3 to double verify with as i figure a backup won't hurt.

Thing is this worked fine first few goes, then suddenly stopped working. Yes I should try a different chip check it works but i also had it with some 16F88 chips.

I've done nothing to the LVP bit, is that low voltage programming ? this is disabled in the project settings. I am using mikroC so cannot program from MPLAB, I use the programmers own software, why shouldn't I ?

Simon · « **Reply #45 on:** October 22, 2012, 09:31:32 am »

Oh let me guess the pickit3 does not have it's own software - great !!!! so how do I use it as a standalone programmer ? or are microchip going microsoft and trying to lock us into THEIR WAY of doing it ?

JVR · « **Reply #46 on:** October 22, 2012, 10:05:21 am »

There is a standalone interface for the PK3, works exactly the same, just difficult to find on their site, I found it via the forums. Don't ever use it though.

LVP is low voltage programming yes, can be a proper ballache. I'd still say, power the chip from an external supply, put a 10 from MCLR to Vdd, shorten the leads as much as possible, and connect the PK directly to the machine, not via a HUB.

Also, as test, put the PK2 into UART mode and do a loopback test, let us know if this works. And, if you have not done it yet, shut down (not reboot) the PC, and try again.

Simon · « **Reply #47 on:** October 22, 2012, 10:08:38 am »

So how can I otherwise use the programmer without the standalone interface, can i use MPLAB to run the programmer with "external" hex files. What is wrong with the standalone software ? I had no problems on the pickit2

I've not changed any settings and it worked before so I'm not sure why the LVP should be causing a problem.

How do you mean do a loopback test with the pickit2 ?

poorchava · « **Reply #48 on:** October 22, 2012, 10:21:47 am »

Don't power stuff from pickit. It's power supply is kinda crappy.

I remember, that on some occasion i was using PK2 to program & debug dsPIC30F5013 (utter crap, that chip, btw). It turned out that when high speed clock was set, the pic would draw a lot of current during startup and the voltage was falling, which would cause the chip to reset. And the chip wouldn't verify ok. Just gave it external power supply and it worked ok (debugger-wise, 30f5013 remained a total shit :/ drawing like 200-350mA @ 5V)

Simon · « **Reply #49 on:** October 22, 2012, 10:23:38 am »

maybe I should put a bypass cap in too! where does it end ? but this all worked fine the other day unless the power section has blown, but then it wouldn't work when on the breadboard and powered either.


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Author Topic: device failure on PICKIT2 (Read 22911 times)

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