I would need to be able to reprogram the butterfly and talk back and forth with it over serial.
I don't want to wander aound in a swamp though so I wonder if anyone has done this. The butterfly expects to be programmed over RS232 serial which I don't have and it runs at 3V. I was thinking of using ICSP to program it but my pololu usb programmer won't work down that low.
I assume that, if i can program it, I can load soft serial in it so i just ignore its rs232 pins. I don't think level shifting from the arduino to 3.3 would be too bad, probably only needed on the butterfly's input.
so, just throwing this out there looking for hints while I look at my avr dragon doc and see if it will program a 3v target.
The butterfly expects to be programmed over RS232 serial which I don't have and it runs at 3V. I was thinking of using ICSP to program it but my pololu usb programmer won't work down that low.
I've been programming an ATtiny13 running off 2 AA batteries using my Uno. I use a pair of voltage dividers for SCK and MOSI. For MISO, I use two transistors to raise the voltage (there is very likely a way to do it with one transistor). For RESET, a simple (but very important) modification to Arduino ISP makes it float or sink rather than source or sink.
Ok thank you. I find that the dragon will work down to 3v and i found a tutorial on using its JTAG with the butterfly on the atmel site - another bunch of stuff i don't normally use.
At the moment I'm trying to see if it will work with a cheap USB serial converter.
this is probably more trouble than it's worth. I can get the serial working somewhat but the bootloader doesn't seem to want to play. I'll go with my own lcd and a couple of buttons. It won't be as pretty but I'll know what I'm doing!
I am thinking to do the same.
I have one Butterfly programmed with the GCC -compiled port and I want to use it as LCD output /Joystick Input for my Arduino Mega.
I am also planning the communication via serial.
Did you finally made it?
According programming, I have an STK500 so I can program the butterfly through the ISP connectors.