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WhiteWizzard
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Joined: 05/04/2013
Location: United Kingdom
Posts: 2932

Posted: 03:09am 03 Feb 2015

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Also - have you set Terra Term to 38,400 baud? (Doesn't sound like this is your issue from what you mention about the Rx LED BUT you need to set it to this value).

WhiteWizzard
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Joined: 05/04/2013
Location: United Kingdom
Posts: 2932

Posted: 03:13am 03 Feb 2015

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As mentioned previously; you need to remove the Rx-Tx short (used to test the USB module) BEFORE you hook up the MicroMite.

If not, then you can potentially end up with 'corrupt' firmware; the only recovery being to reload it (such as with a PicKit3 programmer).

Lets hope you're not in this position . . . .

bigmik

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Joined: 20/06/2011
Location: Australia
Posts: 2949

Posted: 03:23am 03 Feb 2015

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Benzol,

You also need to make sure that pin 1 of the Pic is pulled high to 3v3 (a short will probably be ok but I would always use 4k7 to 10k ohm). The Cap that WW mentioned is + to pin 20 and -Ve to GND (pin 19) if it is a tantalum the + side will have a line if it is ceramic there is no polarity to worry about.

Perth is a long way from me in Melbourne but if you are really stuck, PM me your address and I can send a guaranteed working Pic to you pre programmed. It may be that your chip is not flashed with MMBasic.

Restating items to check.

Cap (10-47uf) across pin 19 and 20
Pin 1 pulled HIGH
Supply voltage between 2.3-3.6v

It is possible that the TTL adapter you have doesnt like 3v3 level signals if it is a 5v TTL level unit but this is unlikely.

Regards,

Mick

PS. Putting a plug in for some of my options I have available please check out this link.

Micks Shameless Plug

Mik

Edited by bigmik 2015-02-04

Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<

Benzol
Regular Member

Joined: 07/01/2015
Location: Australia
Posts: 64

Posted: 03:26am 03 Feb 2015

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47uF across 19 & 20. i disconnected everything else a long time ago. Something has changed, the RX LED in not light any more. i think i will pull it apart a 10th time and rebuild. i'm not a big fan of breadboards and those crappy little pin connectors so i will quad check everything again. TT is set to 38,400 as is the usb port. figured out how to save the config so it comes up right every time. get back to the forum when i have rebuilt again. thanks you for all your help. cheers.

WhiteWizzard
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Joined: 05/04/2013
Location: United Kingdom
Posts: 2932

Posted: 03:33am 03 Feb 2015

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OK - my money is on a breadboard / wire issue!

YES; these do go wrong and I have seen more than five times this type of issue.

What sometimes happens with 'cheap' breadboards is that the 'connecting' strips built in are mounted too low down. End result is you plug in a cable, assume its connecting, but reality is it doesn't make contact with the connecting strip (which is too low). TRY relocating the MicroMite to one ends of the BreadBoard to eliminate a faulty strip.

Also, those cheap breadboard cables that you can buy on ebay often have cables that are faulty resulting in an open circuit. So you can look at your circuit convincing yourself it is connected ok but in fact you have a faulty cable (I lost about 5 hours the other day at a customers house because he had purchase 100 cheap cables for �1!!). TEST each lead with a MultiMeter if you have one. If not, build a simple test circuit with an LED & resistor, using each 'lead under test' one at a time to complete the LED circuit.

WW

Benzol
Regular Member

Joined: 07/01/2015
Location: Australia
Posts: 64

Posted: 04:07am 03 Feb 2015

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Success! A big thanks to WW, BigMik, Jim and Grogster. I think you were right about those cheap connectors. double checked everything and i am now on line. get down to the real purpose of my project. Thank you.

WhiteWizzard
Guru

Joined: 05/04/2013
Location: United Kingdom
Posts: 2932

Posted: 04:19am 03 Feb 2015

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Great News

Don't hesitate to get in touch if you need any help with your project. . . .

bigmik

Guru

Joined: 20/06/2011
Location: Australia
Posts: 2949

Posted: 01:03pm 03 Feb 2015

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Fantastic!

Good luck and above all Have FUN

Regards,

Mick

Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<

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