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Forum Index : Microcontroller and PC projects : *** COMM *** New Mick PCBs now Available
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
All, TassyJim, Has kindly added manuals for MuP-Security and IO Panel on his site. They are here MuP-Security IO Panel Thank you once again Jim, Kind Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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halldave![]() Senior Member ![]() Joined: 04/05/2014 Location: AustraliaPosts: 121 |
Security MuP alpha code slowly coming together.. eta around 2 weeks Please check at the following site for code updates http://mmreference.com/product/mup-security/ |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Hi All, I have had a few people ask me where to get the PCF8574 chip so I will put some links here. Element14/Farnell Currently have a promotion on the PCF8574 at $1.10ea, the thing to consider is $12.50 freight for orders under $35. RS Components $2.53ea in lots of 5 but free next day delivery if ordered online. (I bought my first 5 from them had them 2 days later -- I ordered after 6pm) Both the above are exGST prices (10% extra for GST). It is possible to buy them cheaply on eBay About $4.60AUS for 10 (46cents each) but the ones I got from them, whilst they work look like they have been sitting in an open box and the legs are a bit oxidised, not excessively, but they are obviously not `firsts' Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Hi All, It was mentioned somewhere (I am blowed if I can find the source on TBS now to give credit to the person who brought it to my attention) that the INT line of the IO Panel when pulled to 5V (as is the case when it is used to drive a 4x4 keypad) INT2 in this case needs to be 3v3 max when used to an Interrupt Pin on the uMite. As I have provided, on MuP-Security an Interrupt input to Pin(14) this is not 5V tolerant.. An 18k resistor to GND from the INT line (on the IO Panel) will stop this line from rising above about 3.2V I will look at adding these in a Ver 2 but in the mean time if any of the INT lines are to be used for a uMite an 18k resistor to GND will need to be added. FYI I did a test and risked my uMite and the internal clamping diodes brought the voltage down to about 3.7V, probably not enough to immediatley cause any harm but in the long run it may cause grief and is best addressed now. I will provide pictures of suitable locations for these resistors when I have time to look into them. Regards, Mick EDIT *** Of course this is only relevant when the IO Panel is supplied by 5V, if supplied by 3v3 there is no issue but 5V is needed to drive most LCD Modules. Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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f1fco Senior Member ![]() Joined: 18/03/2012 Location: FrancePosts: 155 |
hello Mick, I am interested by yours PCBs can you send it in France ? the PCB of the Video Terminal is it available ? desciption here : http://www.thebackshed.com/forum/forum_posts.asp?TID=6799&PN =4 than you for answer Pierre 73s de F1FCO |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Hi f1fco, I should have no problems with France, I have sent to UK with no drama so I see no problem with that. As for the MuP-VT, I had, what turned out to be a serious flaw in the layout of the board, coupled with getting caught by the bug in Ver1 of the software where there is no USB comms when PAL is selected. (That made me think I had many more issues than I first thought.) The fault in the tracking was that I added, at the last minute, a 2 pin jumper block to disable/enable 5V from the Mini-USB connector and I inadvertently connected it to 3v3 instead of 5v. It cooked my uMite and coupled with the software bug in ver 1 I pulled out my hair follicles (no hair left) and cut several tracks and rejoined looking for more faults... Well suffice to say it was fun ... NOT!! The bottom line is that if the header is NOT installed and a short 2mm solder link between two adjacent pads the MuP-VT works flawlessly, I actually love it.. I have decided that what I am going to do is cut the track on the header that causes the problem and add a note about it and show where to link two pads and it can be a saleable item. (but the 2 pin header will not be functional) If you are interested the price I have put on it is $4ea (Aus$). Now postage to France should be $3 if I can send just PCBs in an envelope and the total weight is 50Gm or less.. Over 50Gm or over 5mm thick the price jumps to $6.45(Aus) but I can get around 200Gm for that.. If interested let me know via PM or my email is: bigmick58@bigpond.com and I can give you am idea if I can `envelope' it or if it has to be a package. Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Hi All, Further to the Pull-Down issue with the Interrupts on the IO Panel, here is a picture to show suitable locations for the Resistor(s) to be added. 2014-08-25_083258_Pull-Downs.pdf NOTE 1! Pulldowns are not necessary, indeed should not be added, if the IO Panel is powered by 3v3 instead of 5V (LCD Modules usually need 5V) NOTE 2! Only the INTx pin that you are going to use needs this pulldown resistor, I have shown the one for INT2 which is needed for the 4x4 keypad module. NOTE 3! A suitable GND connection is any one of the 3 lower pads of J4 (I have used the Right hand pad) and the 4 possible INTx lines are noted by text, just link your resistor to the appropriate INTx Pin.. Further information will be added to the manual in the next couple of days.. Regards, Mick EDIT *** Before any smarty pants notices, YES I have used a 22k instead of 18k as I am currently out of 18k resistors (probably never had any as its not a value I use often). The 22k was put there as an example of where to fit one.. In actual fact the measured voltage on my INT2 pin with 22k installed (and not fitted to my uMIte) was 3.4V so I would be happy to leave it there anyway. Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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Geoffg![]() Guru ![]() Joined: 06/06/2011 Location: AustraliaPosts: 3272 |
Mick, You should not worry too much over the voltage used for the pullup on the INT pin. I am not sure what value of resistor you are using for the pullup but the clamping diode on the PIC32 3.3V I/O pins can take up to 5mA (if I remember correctly). That means that a pullup of 330 ohms or greater (I would use 10K) to 5V would be OK without a pulldown resistor. Geoff Geoff Graham - http://geoffg.net |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Hi Geoff, All, I used a 10k Pullup. As you suggested the in-built Clamping diodes did work and the actual measured voltage was 3.72V with just a 10k Pullup. I looked at the PIC32MX150 chip specs and they mentioned that too much overdrive of the clamping can cause lockups. I couldn't get any data on the PCF8574 that stated drive current when HIGH (It stated 1.6mA when LOW). I wasn't sure that the current came solely from the Pullup (MUCH less than 1mA) or if the PCF8574 would drive current through as well. When Peter, (aka G8JCF) mentioned the non-5v tolerant status I was a bit concerned. Regards, Mick PS. Geoff are you back in AUS yet? Mick PPS. I might just add it into the manual as a notation and state not to worry about it. Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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Geoffg![]() Guru ![]() Joined: 06/06/2011 Location: AustraliaPosts: 3272 |
Yes, for a while anyway. I have a lot of work built up so MMBasic updates may be initially slow in coming. Geoff Geoff Graham - http://geoffg.net |
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G8JCF![]() Guru ![]() Joined: 15/05/2014 Location: United KingdomPosts: 676 |
PS The I/O Panel has wider use than with only PIC32's, so it would be really great if the Int line was made truly 3V3 compliant so that for example one could use such a useful board with other PIC, Atmel, STM chips etc - not to mention of course the huge increase in the potential market which would then become available! Peter The only Konstant is Change |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Hi All, To complement my range of PCBs I now have some PIC32MX170 chips available.. I have priced these at $8each (Chip only) or $7ea if bought along with a MuP PCB in any option. I also have my MuP-VT which is designed to plug into MuP and provide VT100 comms. I just havent yet completed a proper manual due to family priorities.. These will be priced at $4ea and a programmed VT100 (PIC32MX250) chip will be $8each I will update when I have finished the manual. Photos of MuP-VT plugged into MuP follow ![]() ![]() ![]() Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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mindrobots Newbie ![]() Joined: 21/05/2014 Location: United StatesPosts: 32 |
Darn you! I just ordered a batch of Geoff's terminal PCBs this weekend and now you have these cute little MuPcessory! I will send you an email so we can arrange a trip for a few of them to visit the States! Thanks again for helping me spend my money!! ![]() Rick |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Sorry Rick, I had previously mentioned that I had these boards but there was an issue with one of the PCB traces on it. I have addressed this issue by partially drilling away a pad and when the board is built it requires a short 3mm (1/8") link between 2 adjacent pads. Not the best arrangement but quite workable, I believe.. All in all I personally believe that despite this small error the MuP-VT is a worthwhile addition to MuP.. I know that a picture tells a thousand words but I hope to have a manual soon that explains this issue. I normally wouldn't release a board without a manual, but I have been under the pump a bit with family matters and haven't had much time to put into addressing the problem then creating a manual. Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Hi All, Finally I am in a position to Offer MuP-VT as a PCB. Note, that a medium level of soldering competency is required and I strongly suggest reading through the Manual for the best order to solder the components in as it does get a little tricky due to the component density on this board. There is ONE Surface mount component (mini-USB) that may cause some people a bit of grief, I will be offering an Option 2 that has this pre-soldered but I am still waiting for the banana boat from China to arrive with my order. At this stage I am offering the PCB only for $4ea. If you are desperate, and need a pre-soldered USB, contact me via PM or bigmick58@bigpond.com and we can work out something, I can probably steal a connector from an old board I have lying around.. Tassy Jim is going to host the manual for me, but he is away from his PC till tomorrow evening so in the mean time a temporary location for the manual is Here but that will cease after Jims gets his copy on-line. Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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WhiteWizzard Guru ![]() Joined: 05/04/2013 Location: United KingdomPosts: 2927 |
@bigmik, As promised, I have downloaded your MuP-VT User Manual to MicroMite.org so that it is available for everyone to view online. Very shortly I will be able to supply people this side of the pond with this excellent little module (note: only one in stock currently - more on the way!) I have also downloaded the MuP User Manual; and added the MuP-Test PCB & Manual too. Mick's I/O board and Security boards are next . . . . WW |
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bigmik![]() Guru ![]() Joined: 20/06/2011 Location: AustraliaPosts: 2946 |
Thanks Phil, I appreciate your support. Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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