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Forum Index : Microcontroller and PC projects : CMM interesting issue ?
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| 00WReX Newbie  Joined: 24/10/2014 Location: AustraliaPosts: 13 |
Thanks for the info Geoff. OK, so this is what I did.... mode 3:cls:savebmp "screen.bmp" dots are present (Blue as they always are on initial startup). mode 2:cls:loadbmp "screen.bmp" dots are present (green this time due to being in mode 2 I assume). So I think from what you have indicated Geoff, it is looking more like a RAM issue. Sorry, I don't have a scope for any further analysis . 
Cheers, Shane |
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BobD Guru  Joined: 07/12/2011 Location: AustraliaPosts: 935 |
Have you tried loading MMBasic again. If not then it may be worth a try. Bob |
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| 00WReX Newbie Joined: 24/10/2014 Location: AustraliaPosts: 13 |
Hi Bob, The CMM came with MMBasic 4.4B and the issue was present. I then upgraded to 4.5 and no change to the issue. Cheers, Shane |
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bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2870 |
Hi Shane, Thinking about this it really has to be something faulty in your cpu .. Whatever is causing the original dots is 'written' into ram ( no doubt faulty ram that can't actually be changed) and when the screen scrolls it is read out and written into 'good' areas of ram.. As can be seen when you scroll past the bottom of the screen .. Looking at your soldering, I feel that you should be capable of soldering in a new pic32. Removing the old one without damage will be difficult without a heat gun though.. Have a read on Geoffs site Re surface mount... I was scared off till I read that article. Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
You could remove the old by using some solderwick to take out most of the solder then cut the feet of the chip body with a sharp blade, then remove the feet one by one. It requires patience but is doable. Microblocks. Build with logic. |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2294 |
hi, there are a few further things you can do: 1. take a fine sewing needle and in a quiet place drag the point of the needle gently (at a 45 degree angle) across each of the 4 rows of pins on the PIC while listening to the sound produced. you should hear the needle as is goes from pin to pin making a musical ringing. this may take a bit of practice. you are listening for any tone that is 'dead', varying significantly from the others in the row. do each row in both directions. a 'dead' tone indicates an unsoldered pin. in the past i have used this method to check for pins that look perfect yet have not soldered down. under closer inspection with a microscope these pins reveal themselves as unsoldered. a single unsoldered earth or Vcc pin may cause glitches within the CPU that match up with what you are seeing. 2. look very closely at C10, the 10uF SMD ceramic capacitor, and the soldering around it. make sure you are 100% sure that both ends are soldered to the pads, and that the capacitor has not been cracked when soldered in place. use a multimeter and two sewing needles to check for continuity between each of the capacitor end contacts (on top) and the corresponding pin on the PIC. now check C10 again. if damaged or not securely soldered at both ends this will cause problems with the functioning of the PIC. if you have some flux, apply it to C10 and reflow the solder at both ends of the capacitor. 3. try starting up the maximite with no keyboard attached - people have seen strange behaviour on occasion that seems to follow certain keyboards. as an observer, i have never seen a complete and exhaustive explanation. 4. try a different power supply. cheers, rob :-) |
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Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3167 |
I presume by this you mean that you examined "screen.bmp" on your PC and the dots were in the image. Could you also please zip up the BMP file and post it to this thread. If the dots are in the image then that definitely proves that it is the chip that is faulty. Amazing as I always thought that any defect like this in a semiconductor chip would prove fatal as the memory is in constant use by the interpreter. I would take it back to Altronics. They are reasonably good at making good a defect and so they should at the price that they charge. It would be best to first phone their kit manager in Perth and explain the steps yhat you have taken including the BMP image and this interchange. He should then organise for you to get it back to him. I don't know what their policy is on this - you might be given another kit to build again or they might replace the chip. Geoff Geoff Graham - http://geoffg.net |
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| 00WReX Newbie Joined: 24/10/2014 Location: AustraliaPosts: 13 |
Thanks all for the continued responses and suggestions. Hi Geoff, Actually, no I had not viewed it on my PC. What I did was went to mode 2 on the CMM and viewed the file. In mode 2 I do not see the dots, but when i viewed the file I did see them. So I assumed that also proved they were in the file. So I just put the SD card into my laptop and sure enough the dots are in the .bmp file. At the PC resolution they are not easy to see, but at the maximite resolution are quite prominent. File attached... 2014-10-26_112218_SCREEN.zip Something I only just observed. The number of dots is not always consistent (in the row). They appear to range between 9 and 11 dots at different boot ups. The attached capture has 9, I have just gone back over the previous screenshots I have posted and the 1st lot had 10 and the second lot had 11... Cheers, Shane |
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9078 |
I blew up the image on my PC, and I can clearly see the blue dots. Not a happy PIC32 chip then, I would expect. This is a first. I have never known ANY CMM to have this issue - please, someone, correct me if I am wrong. Smoke makes things work. When the smoke gets out, it stops! |
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| Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3167 |
Amazing, the SAVEBMP command reads the section of RAM that holds the image and writes it to the file. There are dots in the image so they must have come from the RAM, and that is after CLS cleared the RAM. Random bits being turned on would cause havoc with the interpreter and it makes me wonder why you are not seeing any other symptoms. Anyway, you do seem to have a faulty chip in your kit. If you have a DMM it would be worth measuring the voltage on pin 85 (it should be 1.8V) and pin 86 (it should be 3.3V). It is a long shot but low supply voltages could be the cause. Geoff Geoff Graham - http://geoffg.net |
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| 00WReX Newbie Joined: 24/10/2014 Location: AustraliaPosts: 13 |
Just measured the voltage on Pins 85 & 86 as suggested. Pin 85 = 1.848v (+2.67%) Pin 86 = 3.282v (-0.55%) Well within spec from what I could see on the PIC32 datasheet. Cheers, Shane |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2294 |
have you perchance done the checks i suggested above? in terms of probabilities my money would still be on an earth or Vcc pin that appears to be securely soldered but is not. 2nd place to a similarly hidden problem around C10. cheers, rob :-) |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2294 |
Shane: have you managed to get the maximite up and running yet? or returned to altronics for repair? cheers, rob :-) |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9078 |
Yes, I too would love to know how you are getting on with it.(if I may hop on the back of Rob's question) Smoke makes things work. When the smoke gets out, it stops! |
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| bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2870 |
Yes me too Shane.. If altronics won't come to the party PM me.. My busy with time at work finishes on the weekend. Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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| 00WReX Newbie Joined: 24/10/2014 Location: AustraliaPosts: 13 |
Hi guys, thanks for the ongoing concern over my Colour Maximite. Firstly must say, extremely friendly bunch around here. 
OK, I probably should have, but have not returned it or even contacted Altronics about it. Honestly I have been extremely busy with work lately so after putting the kit together have not had as much time as I would have liked to 'tinker' with it. And I also wanted to explore fixing it myself if possible or at least narrow it down. So I have probably missed the boat with returning it...and to be honest I'm sure they could say I must have damaged it with poor handling (static) etc. I have no proof that I have not, but I am conscious of grounding myself prior to working on such things and not being overly 'touchy' when handling boards. It's obviously not impossible though, but it would be a 1st for me. But, I did go over Rob's suggestions the best I could over the weekend (when I was not being called for work related stuff). In the order Rob mentioned above... 1. I tried the needle thing across the pins of the PIC...did not notice anything ?? 2. Checked C10 again and confirmed it is soldered inplace and connection seems good. 3. Booted with no keyboard (I tried this pretty much before I had even posted my issue on the forum...but did try it again). 4. Found another power supply and tried that. So I have used 2 different power supplies and also powered from the USB socket. I also did some point to point continuity tests with my DMM. All as expected. So it still has the same issue with the dots on the screen in mode 3 only but appears to do everything else correctly. The dot's do annoy me a bit though so via autorun.bas I have it booting into mode 1. Cheers, Shane |
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| BobD Guru Joined: 07/12/2011 Location: AustraliaPosts: 935 |
This is Altronics terms regarding warranty on their kits. http://www.altronics.com.au/warranty/ [quote]Warranty on Kits All components supplied in Altronics kits are of high quality and are covered by our standard warranty. However we cannot guarantee components that have been used nor can we guarantee the constructors workmanship. Once a kit has been commenced all warranty claims are void. Should you open a kit and find any damaged or faulty components please contact us immediately to arrange replacements. Similarly, if you open a kit to find it beyond your skill level please contact us within 14 days to arrange a return for credit or exchange. If you have any doubts regarding the difficulty of a kit please contact us for more information.[/quote] Jaycar's policy is nearly identical. They probably use the same lawyer. |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9078 |
I have three or four spare CG CMM units(Circuit Gizmos colour maximite 2's), so if Mick can't help, flick me a PM and I will send you one of these. They were brand new when I got them, but my projects have taken a new path since then, and I now design my boards integrating the PIC32 QFP on the layout, so these boards are surplus to requirements. Smoke makes things work. When the smoke gets out, it stops! |
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