Flashing the digispark with the oneTesla MIDI interrupter code

[profdc9]

Hello,

I managed to modify and flash the digispark with the oneTesla interrupter code.   Here's how to do it:

1.  Buy a Digispark (usually $5 to $10).
2.  Get an Arduino Uno to use as a programmer.
3.  Follow these instructions to plug in the Arduino as the ArduinoISP avrisp programmer:

http://www.instructables.com/id/How-to-Program-an-ATtiny-85-Digispark/

In particular, connect the following pins together

Uno 5V : Digispark Terminal VCC
Uno GND:  Digispark Terminal GND
Uno pin 13:  Digispark P2
Uno pin 12:  Digispark P1
Uno pin 11:  Digispark P0
Uno pin 10:  Digispark P5

4.  Install Arduino software to get avrdude

5.  Flash the Digispark with new code:
avrdude -C"C:\Program Files (x86)\Arduino\hardware\tools\avr\etc\avrdude.conf" -v -pattiny85 -cavrisp -PCOM5 -b19200 -D -e -Uflash:w:main.hex:i make

using the main.hex file from the attached distribution, change the paths and the com port to match your configuration.

6.  Disconnect and plug in the digispark; it should be recognized as a OneTesla MIDI controller.

A single pole-single throw switch is attached to P0, the LED is attached to P2 through a 100 ohm resistor.

Dan

[Mads Barnkob]

Thanks for the guide.

What are the advantages of the digispark over just a arduino uno? Is it just that its much smaller and cheaper?

[profdc9]

It's smaller and cheaper.  I bought mine for $5 on ebay, but you can get Chinese ones for $2 if you want to wait for them.   There's no wiring to do except to add the LED for the fiber optic cable, so it's basically ready to go, it is essentially the same circuit as OneTesla's USB with the pins exchanged.   Also, you don't need a USB to MIDI interface for it, you just connect the USB directly to it.  The disadvantage is that it doesn't use the SD cards, which I wasn't going to use anyways.

I added a spot for the OneTesla USB midi interrupter to one of my interrupters so that it can share the same output LED and save some money there as well, as well as integrate both the test interrupter and the music interrupter into a single board.

Dan

[futurist]

Arduino boards will work the same, it depends on which one are you more comfortable using. Nano boards cost under 3$ delivered and if you use internal FTDI you also don't need MIDI-USB cable