PIC Burner Troubleshooting

[Jaicen]

Ok, i've built the PIC burner+ as per the eagle layout posted, unfortunately it's not 100% working just yet, and i'm scratching my head a little.

I'm getting 13.14v (to program a 16F84) and +5v (7805 runs real hot!) and the green LED comes on just fine. However,  when I run the hardware tests, I can't get the yellow or red LED's to come on at all, which is strange. I did stick in a 16F84 and tried to burn some stuff to it using IC-Prog, which seems to work initially, but fails on the verification. When I read back the hex it's just a string of 0000's, so i'm guessing there's a problem with the data lines.

When I load up P18, it doesn't recognise that I have the burner connected.  At the moment, it's plugged straight into the back of the PC so I can rule out cable problems.

Is it a problem with WinXP affecting the parallel port? I've had problems running 64HDD under XP, I had to make up a DOS boot disk to get it to work properly.

Does any of this sound familiar, or is it just me being an idiot??

[Jaicen]

I don't know if it's important, but I couldn't get any 74HC149's so I used 40106 IC's instead. As far as i'm aware they're pin for pin compatible, and they're only buffering the data lines anyway.

I measured voltages at the parallel port pins and they're all held at +5v with nothing connected.

I also checked the PC port by shorting pins 2 and 10 with a 100ohm resistor but P18 still didn't recognise the burner.

Where am I going wrong??

[Jaicen]

Ok, so the burner is now being recognised when I plug it in, but I still can't get it to respond to the hardware checks. (I had to add a ground wire to the schmitts, as their ground plane is isolated). In P18, when I click the Vdd On button for example, the LED doesn't come on, however if I click Check Data IN, I can toggle it between 1 and 0 using the SDATA on and SDATA off buttons.

I tried to communicate with the burner using ICProg but it's the same story.

Can anyone shed any light on this because it's driving me up the wall! I've blown a whole weekend trying to get it working  :-[

[Jidis]

I had to add a ground wire to the schmitts, as their ground plane is isolated

Weird. ???

I posted a question about a whole "island" of pour on the PB+ that didn't look to be tied in anywhere, but never got an answer. I wonder if it's that same spot. I figured many were probably using that board and that it would have been noticed already, but maybe they're all on regular PB's. (or they tied it manually)

BTW- Mine is only about 60% populated as I didn't have an immediate need for it. I may try to finish it up if I've got time, and see what it does.

Good Luck,

George

[Jaicen]

Ok, well I swapped out the 40106's for 74HC14's, and it didn't help. I then realised that the LED's for Vdd and Vpp were the wrong way aroung  :-[

I swapped them, and I can now get the programmer to respond to the commands that P18 sends out (ie, Vdd ON/OFF etc..).

Unfortunately, I still don't seem able to program anything to the 16F84A I've been trying. Using various different PIC programmers, I can get the software to recognise the burner, and it tries to write, but I get errors such as 'Error in line 0, programming aborted' (from WPicProg16 V1.20). It seems that P18 doesn't recognise the 16F84A, so is there any other (english preferably) software that uses the MBHP burner??? Or is it a hardware issue still?

[Jidis]

Jaicen,

This was the ground pour post-

http://www.midibox.org/forum/index.php?topic=7482.0

I guess that is the same spot you jumped. I'll do mine too. I'll do my best to round up what I need and take it with me tonight. It looks like I stopped soldering when I didn't have the 2.2k trim pot, but I'm sure I can scrape up something.  - Got 16F84A's here as well.

Does it burn anything else or is the 84 the only one you have on hand?

Hope someone can offer some help. I too am curious about the English software support.

George

[Jaicen]

Hey Jidis, I just thought I'd let you know that I finally got my programmer working.

I had to jumper the ground as i've mentioned before. I'm sure that someone else must have had this problem, but I guess they haven't posted about it before.

Anyway, to get it working with ICProg you need to select Tait Serial and invert both MCLR and VCC. As soon as I did that it worked straight off; burned & verified perfectly. I guess we can put this thread to bed now, hopefully it might save someone else three days of headscratching and frustration!

[Jidis]

I guess we can put this thread to bed now

Well, you can at least. Mine doesn't even power up! ;D ;D

Seriously though, much thanks for the tip on the hardware pref. I haven't gotten to the point where I'll be messing with the front end software and chip support yet. I got the board populated fully late last night, but I'm getting no power light and weird voltages on the regulator outs (that 7805 always supplies roughly 5V right?). I'll be checking for shorts next and may be swapping some parts. The 7805 wasn't new. I also had to use regular large size parts in whatever the flat "T0" package style is, rather than the rounded transistor style that the layout looks like. Also could only find one "HC" buffer here, so I've got HCT14's plugged in, but I don't guess that will be a problem until I start programming. :o I'm pretty sure all my LED orientation is correct. I was running an 18.x volt DC supply from a laptop, and it measures as such on the input.

Other things I noticed in my layout:

The 1K pullup on pin one of IC3 (R8 in the .brd) was free on the left (5V) end. I opened it in an older Eagle on my laptop, so I'm not sure if it's like that in all of them.

and:

The two 2-pin jumper's labels are reversed (I think the main power input is labeled as "JP2" in the board).

Take Care,

George

PS- Guessing you're talking about having successfully blown a 16F84A with it right?  - and congratulations on the victory :)

[Jaicen]

Yeah, I was successful with a 16F84 and a 12F675 later this evening (after I made the adapter). I'm stocked that the 12F675 worked first time as it's the primary reason I built the burner. (I'm using it do MIDI sync my DR-110).

It's  a bit of a learning curve but simple once you have it all down and working right.

The free floating end of R8 just needs to be attached to the +5V rail to hold pin1 high.  I didn't wire to JP2, I just wired directly to GND and the +V input, just to save a jumper or two.

Talking from experience, if you're getting something like 10v from the 7805, and it's getting hot, you've probably got it the wrong way around. :-[ The T092 style case (as shown in the layouts) has an opposite pinout to the larger heat-sink type (not sure what case style you call them). Basically, with flat side down, the pins are IN GND OUT (left to right).

Ermm, i'd say you should check the LED's orientation, as both my Vpp and Vdd's were initially the wrong way around. Vpp is grounded through R15, whereas Vdd is the oppsite way around, going to +5v through R7 (on the layout, schem is numbered differently  ::) ).

Anyway, that's enough success for me for one night. I'm off to bed to dream of the day my Dr-110 synchs to MIDI!

[Jidis]

Hey again,

After working on mine again, I realized that the power LED doesn't actually light until the adjust pot hits a certain point, so that's on now. :)

At the test header however, I wasn't able to get the supply up to spec. though. With the pot maxed out, I can get 12.07V tops (supposed to be set for 12.5 & 13.1 for the 16F).

Double checked my input supply, and that's putting out 18.5VDC.

Yeah, I had the 317 in the correct (reversed) position. I actually ended up finding a TO92 version of the 7805 here. I'll probably try to get that style of 317 later too, as it is awkwardly large and has already lifted a trace (all connections are still OK though).

Anybody got any idea why I can't pass 12.07 volts? ???

George

<<<< EDIT >>>>  -Just tracked the problem. The 2.2k trimmer was reading closer to 1.8k. The board I pulled it from had a bunch, so with a more well behaved one (2.1k?) I can now get into the 14 and a half voltage range. :)

[Jidis]

After getting a new pair of 74HC14s, I'm finally back to fighting with this. :-\

Does anyone know any likely reason that I can't turn off Vdd with the P18 software? The Vpp switch in the test panel takes me from 0.4v to close to the 12.5 on MCLR when I switch it, and turns on the Vpp light, but the Vdd line just stays at a little over 5V, regardless of the Vdd switching and there's no LED on for that either.

I've swapped the two HC14 chips around, tried different parallel cables and a different computer, but it looks like the programmer. FWIW, attempting to load a PIC just gets an undetected PIC error.

Thanks,

George

[napierzaza]

Reason why your voltage doesn't go high enough: your trimpot is probably 2k.

check this site and put the resistor value (220) and then 2000Ohm for the trim and you'll see it maxes out. You need either a 2.2k or greater trim pot OR a smaller than 220 resistor. I realized this and had to solder two 100 Ohms in series to make it work, but it's fine now.

oh wait, you realized that, sorry.

[Jidis]

Yeah, typical "old scavenged part" problems. ;D

I'm still planning to dig that stuff out and get it running, but I'm also still in that frantic mess trying to get moved out of my studio, which at this point is either by the 15th of April, or by the end of April (nice margin huh?). Should know which within a couple days.

I'm also going to look into the errors you mentioned on yours before I start anything.

Take Care,

George

[napierzaza]

Mine is completely working now, so it's all you should have to do to make it work.