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Forum Index : Microcontroller and PC projects : Colour Maximite and Arduino Boards
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| multilec Newbie  Joined: 01/11/2018 Location: New ZealandPosts: 5 |
Hello Group, As a Nube to the forum and also to the MM I have an issue which I don't seem to be able to resolve. I assembled my CMM kit from Altronics and had it up and running in an hour or so and all seems to be running just fine. Upgraded the very old F/W to V4.5C no problems. Whilst re adjusting my brain back to Basic from some 40 years ago I decided to have a go with the Arduino connector. I purchased this board from my local Jaycar shop to do some experimenting just today. https://www.jaycar.com.au/arduino-compatible-mini-prototype-board-shield/p/XC4480 When I had plugged the board into the CMM and switched it on the CMM would not boot. But if I hot plugged it after booting it was fine. Bearing in mind that really this is just a standard proto board which looks to be able to be used for a standard 2x16 LCD and the Nokia LCD. There are no added components soldered by me apart from what is already there i.e power LED and pin 13 LED. I checked online to see if there were any gotchyas but nothing. I then decided to try an old sensor breakout shield and again nothing on it but breakouts with the same result. Am I missing some crucial step here?? Ooops, also found this which I would think was the original Chinese board that Duinotech re badge https://www.auselectronicsdirect.com.au/assets/files/TA0041%20Mini%20Prototyping%20Board%20Shield.pdf Regards Nigel |
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Turbo46 Guru  Joined: 24/12/2017 Location: AustraliaPosts: 1642 |
Maybe your power supply capacity is just marginal or the wiring from it to your Maximite is too thin and causing voltage drop? Bill Keep safe. Live long and prosper. |
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| multilec Newbie Joined: 01/11/2018 Location: New ZealandPosts: 5 |
Thanks Bill, I did check that. Im running a 9v 600ma power adaptor from an old wifi router. I changed from a 12v as I think the 5v regulator was running a tad too warm. Voltage checks around the board reveal nothing unusual plus dont forget I mentioned hot plugging the shield had no effect on the CMM. Nigel |
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| Turbo46 Guru Joined: 24/12/2017 Location: AustraliaPosts: 1642 |
OK, I thought that a slow rise time on the processor might cause it to not start up properly. Do you use the front panel switch to turn it on? Have you tried the USB input to power it? I did not fit the connectors for the Arduino shields on mine but I know at least one other has used them with success. Bill Keep safe. Live long and prosper. |
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Chopperp Guru Joined: 03/01/2018 Location: AustraliaPosts: 1097 |
Hi multilec I have a board on my CMM no problems. Bit different to yours. It does have a reset switch on it. Just wondering if yours might be stuck on or something silly like that. BTW, there is an icon, 4th from the left (next to the Underline icon) which enables you to post a link to the URL. It will first ask for a link name eg Link Here, & then the URL itself which you can copy then paste in. Then do a Preview Post & click the link to see if it works. Link Here ChopperP |
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| multilec Newbie Joined: 01/11/2018 Location: New ZealandPosts: 5 |
Thank you guys for your input. Today I isolated the fault to the row of pins on the shield to the D8-D13 row. Since the only thing connected to this row is D13 for the obligatory blink test I cut the track to the LED on the shield. There was no difference in the boot i.e no boot. I then studied the shield closely and did some continuity checks all ok. I studied the underside of the CMM for any problems under the headers all ok. I then re applied power without the shield and nothing, the darn thing gone died on me. All voltages check out, I have voltage on the power LED but no sparklies. All I can assume from this is the PIC has gone, was going bad which is a bummer since I was half way through my space game  Just to put my mind at rest, usually a micro has all pins set as inputs by default unless a user changed them. Is this the case here or are they left floating? Ive not studied the chip so I cant comment if there is internal pull up/downs or not. Anyhow, it looks like a new chip is required. I dont have a pic3 prog so I will try SC for a programmed one. I think I saw some on their website. Cheers all, Nigel |
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| Turbo46 Guru Joined: 24/12/2017 Location: AustraliaPosts: 1642 |
multilec, My CMM died once also. See this link here I was able to reload MMBasic OK. Maybe you have the same problem? I don't know what caused it maybe a power surge? I have had no problem since but I use it infrequently. Try reloading MMBasic as per the SC article or on Geoff's site. Good luck Bill Keep safe. Live long and prosper. |
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panky Guru Joined: 02/10/2012 Location: AustraliaPosts: 1114 |
Nigel, Before you go berserk with a new PIC, they are remarkably tough so I would be surprised if the actual PIC has gone legs up! Short of reverse power, they really are tough as old boots. Do, and then re-do, all the old standards - check for solder shorts, check for opens, check power and power regulators. What is the no-shield current to the CMM with correct 3.3V power applied? My CMM pulls about 140mA using the USB as power. If you see somewhere between 120 and 150mA then almost certainly the PIC is OK. panky ... almost all of the Maximites, the MicromMites, the MM Extremes, the ArmMites, the PicoMite and loving it! |
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Azure Guru Joined: 09/11/2017 Location: AustraliaPosts: 446 |
If you think it is dead, first check the following: Components and traces to C10 the internal voltage cap and R12 the pullup on MCLR; Make sure one side of R12 is pulled to 3.3v; Check SW1 (bootloader switch) is in correct position; Check C12/C13 and X1 look and meter ok. Take it back to bare minimum to check if it will startup - make sure everything else that can be removed is removed (SDCard, keyboard, display, and anything on Auduino and expansion connectors). Did you say the power LED (D7 which is driven by MM chip) lights up correctly? |
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| multilec Newbie Joined: 01/11/2018 Location: New ZealandPosts: 5 |
But I am going berserk lol. It wasn't much to ask, I just wanted to fit a shield. Any how back to the sleuthing. Thanks for the reality check Panky, I teach all my students the same thing. Ok, after I last disconnected the power I let it sit for a while to enable a coffee. Damn me it booted up again. Plugged unplugged booted every time. Put the shield on, it booted. Took the shield off. It didnt boot. Took the board out again and touched all the connections with the iron, reinstalled the board. Nothing. So before reaching for some more serious equipment I poked around the chip with my poky thing and she booted up. Looking at the chip through the magnifier everything looks good, there are a couple of places near the corners of the chip that look like an iron has been dragged but all in all good. Put another firmware on and back to square one. Prodded again and it booted. So, it seems more than likely the chip is good, but not on good. This maybe would explain why I had weird booting when I fitted the shield as it must be flexing the board to some extent. The board is drawing 126mA bare and 132mA with the shield on which would be the power LED. Nigel |
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| Azure Guru Joined: 09/11/2017 Location: AustraliaPosts: 446 |
Check for dry joints around the components I mentioned and their pins on the PIC, these are the minimum it needs to power up. Also check the voltage at the PIC when it does not boot up. An intermittent fault from a dry joint somewhere is waiting for you to find it. |
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| Turbo46 Guru Joined: 24/12/2017 Location: AustraliaPosts: 1642 |
Because you've had it working your construction is probably OK except for a suspected dry joint. Looking at the circuit there is not much that will prevent it from booting: Most of the I/O pins won't stop it from booting unless there is a short circuit which seems unlikely. Remove the SD card, the Arduino shield and the keyboard. Try booting again. Power supply - try a USB supply, that will eliminate part of the circuit. If it boots reliably then check the components to the left of D2. If it doesn't boot then use your 'pokey thing' (insulated I hope) to prod REG2 then all of the Vdd and Vss pins on the chip (I don't know the consequences if one of them is open circuit). Check the rest of the components in the power supply chain above the chip in the circuit diagram. Oscillator - check the joints around that part of the circuit. Tap the crystal gently with your pokey thing. Are the correct capacitors installed? Bill Keep safe. Live long and prosper. |
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| multilec Newbie Joined: 01/11/2018 Location: New ZealandPosts: 5 |
Gentlemen, We have a resolve, I managed to replicate the no boot scenario. Testing around the chip we have an area around C9 on the chip pin 85 86 where we should be getting 3.3v. Not sure if pin 86 is responsible for boot up or not but looking at the schematic this pin and many others are interconnected to 3,3v line, this area also feeds the 10uF SM cap which I know has a big role in boot up. This area on the corners of the chip as mentioned earlier look to have been touched up by hand. Probing the pin gently from the top revealed no 3.3v. This is very hard at this pitch since one look away and you have to count all over again from the corners. Probing from the side of the pins revealed my lost supply. This must be a very marginal contact since i've literally had this unit on for days since built. My interference with the board trying to smooch the shield on has obviously made things worse. A touch with the iron sorted this immediately and fixed the issue, and I can now use my shield  Thank you so much to all especially Azure,your clue around C10 was the first place I looked as I had read here somewhere that C10 could be a bit dodgy sometimes. Any how all good for now and I can carry on with my space game. Nigel |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 4044 |
Good job finding that! John |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 5091 |
Too late reply..... I had one of those exact same arduino experimenters boards, and it had a layout fault. On the arduino there is a pin that connects to Vref of the ADC s. On that experimenters board that pin was hard wired to 3.3 volt. I could not see any soldering problems on it, so i ended up removing the pin. Maybe you have a similar board, and i cause a problem on you cmm. PicomiteVGA PETSCII ROBOTS |
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| Azure Guru Joined: 09/11/2017 Location: AustraliaPosts: 446 |
Glad you found that elusive dry joint and have it working now. |
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