Two little issues (resolved, dead PIC)

[naztrain]

I built my first LE and it is 75% operational.  I have two problems, but I'm not sure how to resolve or troubleshoot them.

Channel 6 LED remains dimly lit while the LE has power.  It reads 1.5 volts across the LED, but at no time will Channel 6 actually turn on.

Channels 10-12 LED does not light, and the channels themselves does not turn on either.

Neither problem is resolved by swapping the Optos for one that works.

Other than that, the LE seems to function as normal (the test program works just fine, barring the individual channel failures).

I feel like this could be a soldering problem, though I can't see any bridges or gaps anywhere, and I was pretty convinced when I was soldering that I had not left anything like that anywhere.  I'm going to do a more thorough search once I have some real daylight again.  In the mean time, does anyone have any ideas that I'm not thinking of?

Thanks!

[rrowan]

Check the soldering around the pic and or make sure the pins are not bent.
Channels 10-12 could you put the leds in backwards?

Make sure you use a magnifying glass while looking at the soldering

Rick R.

[naztrain]

I did another check of the PIC, it still doesn't look like any solder problems, but I'll check again tomorrow with sunlight.  I reversed one of those LEDs, but I'm still 99.99% positive that I put them in right. 

[bisquit476]

An easy check for the LED's is to get a watch battery (I use the CR2032), put one leg on one side, one on the other, if it lights the LED, the polarity is correct, look at which side is which so you see what side is the positive. If it doesn't light, spin the LED around, and try again (to verify the LED works). I generally test all the LED's before I put them in place. (Yes, even with the Aeon, all 72 LED's got tested) I figure it's easier to test first, instead of re-soldering later.

[rm357]

Try re-flashing the firmware in the pic. Dim led 6 and a slow display on the three 7_segment displays are common indicators for something not going quite right when the pic was programmed...

Rm

[naztrain]

Yikes, school got very much in the way there for a while.

Alright, so I tested the line to channel ten from the PIC, which reads 0 volts always. 

The Express communicates just barely with Vixen, but not with the DMX deck, which makes me think it's the Pic (for instance, a channel test on Vixen will turn the channels on at 30% power when the percent on Vixen reads 97%, which is true for channels 1-9.  The others are unresponsive).  How can I go about getting it reprogrammed?  I don't have a PicKit2.  Would it be best to buy one or send the pic to someone?

[combustionmark]

I would buy a pickit 3, Is this the only express board you have? If you have another, try the suspect chip in the other express. A little odd that dmx deck doesn't work, did you select the correct com port under setup? If you have to reprogram the chip, try finding someone near by that has a pickit.

Good Luck

[jess_her]

Hummm, if channel 10 at the pic (pin 18 at the pic) is 0 VDC then the AC output  (where the lights plug in) should be 100% on.  The Pic's channel control side is just a variable switch and all it's doing is grounding the Opto 3023 to turn on the tric.  Pin 18 on the pic 2.6 VDC(can't remember but it's close) is off, 0VDC is on. You have two different types of power on this board AC and DC your reference ground should be here for the DC (pic voltages). Skip to the end of the thread.
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I'm with combustionmark check your com port setup, I used Bill's how to video You are not allowed to view links. Register or Login    very helpfull.
If your going to jump in neck deep with this stuff then I would get the  pickit 3 with the J1sys adapter boards   

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You can program with just the pickit 3 through the on board  ICSP header but for me I like the zif boards.

 

[naztrain]

Alright, the picKit3 arrived, I reprogrammed the thing and the LE ran the test sequence perfectly.

However, it still has some concerns about communicating through DMX.  It seems to hang at various sporadic times and light values, sometimes remaining stuck on, other times remaining stuck off, or at half power or anywhere inbetween.

The LEDs seem to accurately reflect the same output as on the 120V lines, so my problem is happening somewhere between the LEDs and the computer.

I'm going to reflash the pic again and see if that helps for some reason... but if anyone has any suggestions in the mean time, do tell!

Thanks!

[naztrain]

More info:

After erasing the pic and doing a blank check, it says the blank check failed.  I'm wondering if that means the pic itself is bad.  It has no problems erasing, writing, or verifying.

The DMX light turns on when expected, and the signal is passed when other controllers (SSR4s) are put inline afterwards. 

Would any of the other chips cause this to happen?  If so, which?

Thanks!

[jess_her]

read down this thread  last two or three posts might have your answer.

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check for these resistors right above the pic
Yellow, Violet, Red, Gold

It's hard to get a feel for whats wrong,
we know its passing DMX on  but it may not be getting good data to the LE
1) is the wireless jumper in?
2) good solder joints at the RS485 socket between the DMX in and the termination jumper?
3) good 5v power? checked with a meter? but I think you said you have display digits.
4) check the thread for the resistor value.
let me know


2) check the solder joints at the termination jumper

[naztrain]

Those symptoms seem to match mine, though I don't have access to the board right now to do any kind of further testing.

The jumpers are correctly placed (I even tried various combinations just to be sure something weird wasn't happening, though admittedly the board doesn't seem to do anything differently with or without the termination jumper, so I'll go back and re-solder it just to be sure.)

I'll re-solder the sockets as well, just to be sure.


I don't recall anything fishy about the 4.7 resistor, but I do recall that the blue (120 ohm) resistor's color code was not the same as the description in the wiki, though it matched the picture in the wiki so I assumed it should work.  Could that cause this kind of issue?

I didn't test it with a meter, but the 5v LED is lit.

I'll look into that as soon as I can (later this afternoon).  Thanks!

[jess_her]

 on item 2) I meant to say solder on the wireless jumper.

The termination resistor colors called out  brown, red, brown, black
the resistor are brown, red, black, black,  brown

It sound like you have a DC volt meter. Just for fun can you check the 5V.
This is the power for your rs485.
Don't mean to hover here but this is  for your DMX data.
The green  5V led is on but for me I'd check it with a meter.
ground side of your meter to bottom (4 hole) left side of your wireless module thought hole.
plus side of your meter to the right side third down of your wireless module thought hole.
 
4.7 K ohm resistor at the top of the pic   Yellow, Violet, Red, Gold
47     ohm resistor, if installed at the same place will cause a programming issue  Yellow, Violet, black, Gold.

Last thing for now  are you programing through the ICSP header or do you have an adapter board?    Some adapter boards need jumpers installed.

Go to go to work I'll check in tonight 11 pm.

[naztrain]

Preliminary update:

The resistors all seem to be outputting the value mentioned in the wiki.

My 5V reading is accurate.

I'm using the ICSP header.  However, I did feel a bit lost while actually programming the PIC.  I'm using the software provided with the PicKit3.  Is there a download of a specific programmer software I can use?  The one I'm using looks absolutely nothing like the one in the Wiki.  Could I simply have programmed it incorrectly after it had been flashed incorrectly the first time?

I have 2 new PICs I ordered today just in case I do need a replacement.  I also picked up two RS485 's from my Electrical engineering supply room at my university in case one of them is dead, though I'm hesitant to use them because they are printed differently from the ones on the Mouser list.  These have "MM238E   DS751768M" printed on top.

The shop lists them as follows: 
"IC-DS75176    $2.00    IC-Transciver Mult. RS485/422, $2.00"

Are these valid replacements (assuming I need to use them)?

[naztrain]

Well, I resoldered most of the pre-pic components (including the pic socket itself) and now the test program runs fine until the end, where LED2 no longer lights up and now there is no response from the express AT ALL from the computer end (whereas previously it had some erratic responses).  I tried re-flashing the pic again and this time it said there was an error:

"Address: 000015f2 Expected Value: 00ffffff Received Value: 00fffffe"

I then tried it again with the same result, and a third time and it programmed correctly, but with the same result (test works, but LED 2 does not remain lit and there is no communication with the computer).  The DMX light does remain lit.

I'm lost.