EasyPIC4 programmer problem

Hello everyone,
I'm stumped, I finally got to go home over Thanksgiving and picked up my programmer to try some designs out that I came up with. Last night I got it all set up and was going to program a 12f615, for which I wrote a simple flashing LED program to make sure I remembered most of the things to do with it. Anyway when the program that actually flashes the chip loads and tries to load the hex it puts up an alert box saying "Vpp voltage error! (3.16 volts)". After reading I thought maybe I'd gotten a setting wrong but since I read on one manual that the easypic didn't support low voltage programming but after checking all of my settings in the programmer were right, I had low voltage programming disabled.

I wasn't using the power supply I'd been using with it in the past because I left it at my schools rock wall because it was powering out stereo there so I picked up one for my guitar pedals that I remembered using before. After checking it was a 9v wall wart, which the other was variable but I thought it had been on 9v too but I went to the electronics store and picked up a 12v 500mA wall wart to use since the programmer accepts 8-16v. This didn't work either, I even tried using a couple of different chips that I had successfully programmed with that programmer before (16f877a) and that didn't work either I still keep getting the same message. I've tried moving all the jumpers and nothing is working. I even went back and uninstalled the new software and installed the old drivers and flashing software but that still gives the same message. Has anybody had this problem or have any ideas what it could be? The board worked the last time I used it and it's been in a pistol case I bought for it under my bed since then (about a year).

Oh I checked the pin voltages and the VCC to GND is a steady 5.05v and the Vpp (which is the MCLR pin right? 99% sure but thought I'd make 100%) to GND is about 1.5v till I hit the program button then it rises to 3.16v and stays there till I hit "ok" on the alert window then it falls back down to 1.5v. Any ideas on what to check or thoughts on what to look for on the board? I have no clue anymore I've been messing with it all day.

I appreciate any thoughts or help. Thanks again.

Is the pin-out reversed on the power adapter?
(polarity)
Center pin ground, versus sleeve ground?

Well I did consider that because the adjustable wall wart had a polarity switch on it but the programmer says it accepts both ac and dc power and it has a regulator and a rectifier on the board so even if the polarity is backwards it shouldn't matter right? I may be wrong there (probably) but I was assuming the rectifier would fix the polarity issue. Plus the board is getting power and I can't remember the last program that was on the 877a but I'm guessing it had to do with LEDs or something because it shows output on a couple of pins when I first plug it in. Thanks for the help though I'll go see about it when I get a chance.

It was just a guess. I use the 6, and I have never had that problem.

Are you resting the bottom of the board on anything conductive that may be shorting a pin or two? Metal top desk? (Another guess)

You have tried different packages? 8 pin, 20 pin , etc... ?

I have only tried two chips at the moment the 8pin 12f615 and the 16f877a which is a 40pin. I have an 18f somewhere thats a 28pin but I don't think it's good anymore I think I messed up one of the pins when I desoldered it out of a project. I also have another 12f615 that I could try I suppose.

I made sure that it wasn't sitting on anything conductive, I've had it on a wooden desk and it's got the rubber pads on the bottom of the board that let it stand up off the table enough so that nothing touches.

One thing I've been sort of puzzled by is this little three pin thing sitting just to the left of the DIP sockets labelled MCU POW. SW. it looked like a voltage regulator to me. The center pin is cut off though. The left pin reads almost no voltage, like 0.02v or something. The other pin reads 5.05v. The number printed on it is the following:
FR9024N
I↓RP609G (the arrow is a diode symbol)
A2 F3

I tried looking up the datasheet to see exactly what this piece was but had no luck, the results that did come up with were all MOSFET's etc but they had more numbers than just these.

I also found a website with the schematics for the easypic4 so I'm going to be using that to completely go through the circuit but as I just glanced as it I saw no MCU POW. SW. in the schematic so I don't know how accurate the schematic is but it's still better than nothing I guess. Here is the link to the page with the schematics that I found.

Here is the part (MCU POW. SW.) that I was referring to:
**broken link removed**

It is a P-channel HEXFET.
The center pin is internally connected to the body.

So, that is the 3rd pin.

Here is the datasheet
IRFR9024NCPBF pdf, IRFR9024NCPBF description, IRFR9024NCPBF datasheets, IRFR9024NCPBF view ::: ALLDATASHEET :::

Thanks I appreciate that, thats the part I looked up but wasn't sure if that was for sure thats what it is. I appreciate it. Hmm.. well I'm stumped now...

Hi,

A couple of things might help - as you say the diode block should stop any dc reverse connections, but rather than mess around with wall pacs why don't you use the usb cable power .. ?

Would also go and check all of your jumpers as some of the programmer ones might be displaced, the readings on Vpp don't sound right, if Vcc is ok at 5v.

Should check for shorts on Mclre pins of all the socket and also see if you get the same reading with and without the pic chip in the socket.

If all of your chips are suspect / damaged it might be worth getting someone to program up a new chip with a simple led flasher program to see if you can actually run anything on it before you try to program anything.

Incase you didn't know it is possible to deselect the Mikroe programmer and wire up a Pickit2 programmer which allows you to fully integrate MPlabs programmer and debugger functions.

Hello, thanks for the reply.

When if first got the programmer a couple of years ago I originally started trying to use the USB connection for power but that doesn't work. Mainly the reason it doesn't work I'm using a laptop and it can't power it sufficiently for programming, it just powers down then restarts when you try to flash anything using USB. And I thought it was because the laptop can't put out that much from it's USB ports but all my PC's at home that I tried it on still didn't work so it's just a lot easier to use an external power supply so I don't have to worry about it.

I've checked the positions of all the jumpers and double checked them and can't find anything out of place. But I will check the sockets and see what it does without the PIC in it.

I would get a chip programmed but there's nobody around here that has a programmer and there isn't a supplier around here that even knows what a microcontroller is haha. I'll try this but it's going to be a while before I can get around to doing that.

How can you deselect the MikroE programmer? I wasn't aware of that. I have been thinking of making a new programmer when I get the money. I have most of the components but it would be a lot easier if I could get this one to work.. I could at least skip building the initial serial programmer and go straight to the USB programmer. I still like the EasyPIC4 though and still want to get it working again so I can have two of them to use it's a lot easier to write test programs on it without having to build a circuit or anything.

Thanks for the suggestions I appreciate them and I'll go try them out as soon as I get a chance and get back to ya'll with what I find.

How can you deselect the MikroE programmer? I wasn't aware of that. I have been thinking of making a new programmer when I get the money. I have most of the components but it would be a lot easier if I could get this one to work.. I could at least skip building the initial serial programmer and go straight to the USB programmer. I still like the EasyPIC4 though and still want to get it working again so I can have two of them to use it's a lot easier to write test programs on it without having to build a circuit or anything.

Click to expand...

Hi,

Well I helped a friend do his EP4 board, I don't have one myself.
He's probably just seeing this post as he's on your West coast so he will possibly drop in an let you know the detail.

If you have had a problem with the USB powering from day 1, I would suspect you problems run deeper than you know.

Are the caps on the input of the USB in place?
Is the USB/EXT jumper set properly? Are the pins bent?

Yeah the jumper is set to the external power source. And the caps are in place and by visually look to be fine but I haven't checked them.

The USB thing hasn't worked since the beginning but I have read on their faq or somewhere I can't remember that laptops usually can't put out enough power to program it though it will power a pic thats in there. That part doesn't worry me really because I understand that but this programming voltage being too low is driving me crazy.

I just checked all the sockets without pics in them and the dip40, dip8, and the dip28 were all 1.33v. The dip18a was like .012v as was the 18b and the 20 and 14 were 4.43v. If I had some pics with anything but 8 and 40 I'd try those other sockets out with pics in them but right now the only other I've got it the 18pin and I'm afraid to put it in because one of the pins feels like it's about to break off and I don't want to risk getting it stuck.

Again thanks for the help guys I appreciate it. I'll give more info after I do some more poking around with it.

You can download the full EasyPIC4 instruction PDF and EasyPIC4_schematics_v102.PDF from MikroE.com.

Check around the 74HC4053 (actually two 4053s) which I think are a quad analog switch, they are used to switch the programming lines to the PICs when in programming mode.

Also there is a FET that switches power ON for all of the PICs Vdd pins, that is usually labeled pretty well. And in the ICD programmer area I think there is a FET or transistor that is used to pull the Vpp pin up to 14v to perform th eprogramming, you should check it too but I'm not sure which one it is out of the 7 or so there...

Thanks for the FET info I hadn't thought to check that. To be honest I'm not sure how to go about checking that, would I just connect the power and read the voltage on the legs when it programs?

I'll also check on the 74HC4053, I haven't looked at the data sheet for that but any tips on checking that would help too.

Thanks again guys, I really feel like I'm (we're) getting closer to solving the issue, I feel like it's just right under my nose.