Author Topic: ATTINY85 and Micronucleus - Digispark  (Read 3242 times)

nunocostal

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ATTINY85 and Micronucleus - Digispark
« on: May 16, 2015, 10:12:27 am »
Hi,
I bought digispark board, and designed all my code and validated it with my peripherals. All good! Perfect devide for the purpose.

Now... This is a custom solution, and need to fit inside a box, etc... so I had to design my own schematic.

For now.. it is ALL the same as Digispark, since I did nto connect yet any other device. Using a breadboard for now.

Using AVRDUDE/AVRDDSS2.4. I am flashing code image micronucleus-1.11.hex
Fuses are E1, DD, FE.
Do I need to send a command to set clock also?
AVRDUDE seems not to get fuse settings from HEX file, so maybe not there.

Result is: ALL OK from the programming perspective. I program and verify all ok. when I connect to a usb port, using similar circuit as Digispark, I get nothing.
Also tried the HEX with PB1 having LED to signal bootlaoder, but still nothing happens...

Ideas?

edit:
do I need to run any OSCCAL before? there is code on github, but nothing referencing if we need to do it. It must run in overdrive to allow 16.5MHz... so not sure need any action.
« Last Edit: May 16, 2015, 03:51:56 pm by nunocostal »

nunocostal

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Re: ATTINY85 and Micronucleus - Digispark
« Reply #1 on: May 16, 2015, 07:44:25 pm »
Solved.
Explanation:
I don't like the zener diode solution and my system will work at 3.3V atually. So I was powering my tiny with 3V3.
All good. It means that I do not need zeners.. (sure for 5V use the must be there! no argue)
BUT i forgot the pullups...causing the problem.

So if your system is 3V3, you get rid of a few components.

Also, SoftwareSerial needs some adjustments for 115k baud rates. (my system scrolls baud from 115k to 1k2 baud.

Littlewire is awesome.

Cheers
Nuno