08m2+ not progaming above 3.01v

[dennis shubert]

I put together a 08m2+ download circuit (as I have before with success , however I can only get a good download using a regulated power supply from 2.5v to 3.01v. Anything above or below this voltage causes a reset, and or a download error.Do they make an 08m2+ that uses only 3.5v maximum. Or my cirtcuit has flawes in it. Any help would be appreciated. Thanks DCS from Colorado USA.

 

[Goeytex]

Probably a circuit error. However you have not given us very much to go on.

1) Are you using an AXE027 for programming or something else? If something else, what ?
2) Are the 22K and 10K resistors fitted properly ? See images below
3) Is the 100nf capacitor fitted?
4) Is anything other than the AXE027 attached to either the serin or serout pin?
5) What type of regulated supply ?
6) Are all the grounds tied together ? Power supply ground, picaxe ground and AXE027 ground must all be tied together
7) If on a breadboard, take a clear close-up photo and post it here so we can see.

 

[AllyCat]

Hi,

Yes , all of the above are good points to check. But 2.5v is indeed the minimum programming supply voltage (Brown-Out Detector Reset Level of the 08M2) and a maximum of 3.0x volts strongly suggests a Programming Interface voltage level error. Either the > 3v Output voltage Logic level (from c.0) is too high, or it's the Input threshold of > approximately1.2 volts (on c.5), particularly caused by point 2) above.

Cheers, Alan.

 

[hippy]

It is odd. In relativistic terms, reducing the PICAXE supply voltage increases the voltage supplied into Serial In which could point to an issue with the in-line 22K resistor of the download interface, perhaps an issue with the AXE027 cable, or an issue with the wiring of the download interface.