 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Microcontroller and PC projects : help with power up on colour Maximite
  Page 2 of 4   |
|||||
| Author | Message | ||||
MicroBlocks Guru  Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Does this mean that a 10uF for VCAP is not enough capacity or is it that it was a tantalum and not a ceramic one? I use the 10uF ceramics all the time without problem. Microblocks. Build with logic. |
||||
| jeffj Regular Member  Joined: 04/02/2012 Location: AustraliaPosts: 80 |
Thanks for yr comments I installed all the caps permanently except for the osc caps and it runs ok I swapped the 12pF caps for the 22pF and it wont run I couldn't get it to kick start by shorting one out either I put 12pF back in and all hunky dory, regards Jeff |
||||
| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2794 |
Ditto MicroBlocks; I have also used 10uF ceramics on literally hundreds on MicroMites and NEVER had a single issue. They are available in SMD and in through hole. Through holes are either 2.54mm (0.1") lead pitch or 5.08mm (0.2") pitch. Ceramics are NOT polarised and hence will 'just work'. Maybe it is worth eliminating this type of scenario experienced by jeffj by simply changing the Manual to advising the use of a 10uF ceramic (and dropping any mention of 47uF tantalum altogether)? Not to mention, the ceramic has an all-round better spec than the tants, and are also cheaper (win-win-win!) 
WW For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
||||
| twofingers Guru Joined: 02/06/2014 Location: GermanyPosts: 1141 |
I doubt that we will ever get a new manual for MAXIMITES. AFAIK is the MAXIMITE at the end of his life cycle. 
For MICROmites I use 47µ ceramics (SMD, X5R-G1206 47/6) and tantals (Because I have hundreds in my experiments box.) with success. I would recommend the 47µ ceramics (for uM2). Michael |
||||
| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2794 |
Let me be clear, I am not saying that a 47uF tant vCap won't work, just that there is a risk of the MM not working IF you put them in the wrong way. Having stock, and inserting them correctly is fine!. But the fact that jeffj had to post goes to show that it is possible to make a mistake. This scenario would not have arisen if 10uF (or 47uF) ceramic had been specified. I think we can all agree that we should 'reduce' people's chances of making a mistake! when playing with a MM For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
||||
| twofingers Guru Joined: 02/06/2014 Location: GermanyPosts: 1141 |
@WW I completely agree! 
I just wanted to point out that there are higher values for ceramic caps available and applicable. Microchip manual for Pic32mx795 p.45 Moreover, I'm pretty sure that you are far more experienced in building Mites than I do. 
Michael |
||||
Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3167 |
I recommend 47uF tants because they work well and 10uF through hole ceramics are not that easy for the ordinary experimenter to find. Australian retailers (Altronics and Jaycar) do not stock them and last time I looked even Element14 charged silly prices or did not have them in stock. SMD ceramics are another story so I recommend them whenever SMDs are used. Geoff Geoff Graham - http://geoffg.net |
||||
| jeffj Regular Member Joined: 04/02/2012 Location: AustraliaPosts: 80 |
I have just been swatting up on tantalums . If you put one in backwards and I am sure I could have done, it could be damaged ,also likely to overheat and catch fire if not protected.Some tantalums have long and short legs the ones I bought from Jaycar had the same lengths On a related topic I have never seen any blogs on how to get these 100 pin devices out without damaging them. For what its worth I will describe what I did I fixed a hot air gun in the vice pointing up .I the held the card with the heat directly on the back of the card and chip .As soon as the solder melted I tipped the card over and the chip fell out (That was when I lost the ceramic cap that was originally there). No damage to pcb Jeff. . |
||||
bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2870 |
Hi Jeff, All, I am glad you have it up and going, Phil aka WhiteWizard, has been trying to convince me into the 10uf ceramic cap path for a long time now.. My story was similar to yours.. My original Maximite had similar issues, it was a 10uf tantalum. It was a friend of mine and fellow TBS member Stuart Smith who worked out, accidentally, I think from an accidental probe short, that a 22uf Cap in parallel to the 10uf made all the difference between total failure and perfectly working.. Then I had the UBW32 boards of which I made my adapter to turn it into a Colour Maximite and I discovered similar issues with the 10uf tantalum they used. I have ever since (and still do) use 47uf 6v3 Low ESR tantalums for my boards.. Why have I not taken Phil's, well founded, advice? Well I cannot really answer that except to say that since using 47uf Tants I have never seen any problems at all with reliability and something deep inside me says that 10uf is not quite enough... Given, the 47uf caps are considerably more expensive and are also polarity conscious but they work and work very well (provided they are not reversed) The bar for +ve is a confusing convention as most people would see that that should be the GND side.. Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
||||
| twofingers Guru Joined: 02/06/2014 Location: GermanyPosts: 1141 |
Thanks Jeff, it's always good to know. So far I only knew the cutter method. Regards Michael |
||||
| paceman Guru Joined: 07/10/2011 Location: AustraliaPosts: 1329 |
I think it's a bit "six versus half-a-dozen". I've used 10uF SMD ceramics for the last four or five I've made up but of course they do have to be X5R's not X7R's. Either way the user has to be careful what he/she does - i.e. if your preference is to use ceramics and not have to worry about polarity then do worry that you buy the X5R type not the more common X7R type. If you intend to use a tantalum, you have to make sure your Ta is soldered in the correct way. Greg |
||||
| Lightrock Newbie  Joined: 19/05/2014 Location: AustraliaPosts: 26 |
bigmik's comment about capacitor marking solved the problems I had with bigmik's SMD Backpack 170 board and also Z-Cards 44 LCD Prototype Board. Now able to program both boards! Ceramics only for me in future. Roy |
||||
| jeffj Regular Member Joined: 04/02/2012 Location: AustraliaPosts: 80 |
Hi folks sorry to be a pain after all the help you have given me The maximite is working ok screen ok keyboard ok sd card reads ok but i just cannot get the MM to communicate with the computer I have checked all conns and cable all seems ok I understand that the mm should show up in device manager under "other devices" There is no "other devices" showing up . I assume this is only displayed when something is found . I put the scope on pins 56 and 57 and there are no pulses pin 54 has 5 volts on it. The computer doesn't ding when plugging in or out the usb plug. The computer was working ok before I changed the chip and ports work ok . Yr help would be appreciated |
||||
TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 5923 |
What version of Windows are you running? Assuming that you are NOT running W10, If the board worked previously, you must have installed the Silicon Chip drivers. If so, the maximite would appear under "ports (COM & LPT)" If there is a problem, there will be a device with a yellow exclamation mark, either ports or other devices. If you ARE running Windows 10, it might appear as a Microsoft serial port. The usual first step is to reboot your computer with the maximite unplugged. Jim VK7JH MMedit  MMBasic Help |
||||
| twofingers Guru Joined: 02/06/2014 Location: GermanyPosts: 1141 |
Hmm, can you confirm a installed Silicon Chips COM port driver? 
Michael EDIT Jim just beat me to it! |
||||
| jeffj Regular Member Joined: 04/02/2012 Location: AustraliaPosts: 80 |
Thanks for those posts I have tried rebooting the computer no effect I am running windows7 on my laptop "Ports and (com and LPT)" does not appear "Other devices" also absent I down loaded the silicon chip serial port program into my desktop running XP and I have three yellow entries 1 PCI simple comm controller 2 Unknown device 3 ditto Jeff |
||||
| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2294 |
this may help: 1. right-click on the unknown device and delete it. 2. unplug the USB connection between maximite and computer. 3. re-connect the USB. 4. when prompted for drivers, navigate to the silicon chip drivers you downloaded. i've not followed the thread too closely, but if windows marks a device as 'unknown' it can often be quite determined about not installing any drivers for it until the 'unknown' entry has been deleted. this is why many printers and scanners come with a label stuck over the USB socket telling you to NOT plug in the USB cable until AFTER you have installed the supplied drivers. cheers, rob :-) |
||||
| TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 5923 |
On the XP machine, look at devices before and after inserting the maximite. That will tell you if the PC sees any changes. The maximite will hopefully be the unknown device. If so, you can right click and update/install driver as per the Silicon Chip instructions. A different USB cable and different port on the PC is always worth trying. Jim VK7JH MMedit  MMBasic Help |
||||
| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2794 |
One thing that has worked for me on several occasions (when totally stuck) was to begin the re-install of Windows. Initially it will go through the process of 'setting things up for the install'. But then you can back-out at the last minute and the 'problem' then sometimes goes away. This has helped me out when I have had issues installing other hardware. I am not saying this will sort your issue out - but it maybe one worth knowing about for future!! WW For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
||||
| jeffj Regular Member Joined: 04/02/2012 Location: AustraliaPosts: 80 |
Thanks for yr posts none helped unfortunately I think there is a problem with the chip as no pulses on the scope. Unfortunately I don't know what to expect. I had my computer repaired last year and I didn't get the instal disk back so couldn't pursue that avenue Jeff |
||||
| Page 2 of 4 |
|||||
 Print this page |
