ISP or Serial programming an Arduino
February 27, 2011
I am the proud owner of an uBotino board by Robot-x. I do not own a USB-to-Arduino cable (FTDI with auto-reset). However, I do own computers with good old fashioned serial ports.
So I think I'm gonna build a serial programming circuit. Would the classic "Picaxe" level-correcting schematic work in this case?
* a voltage divider to shift down the signal from my PC from ca 11V to 5V;
* a series resistor in both data lines to limit current;
And what about the auto reset? Is that just a matter of connecting Arduino's RST to PC's DTR? Should I protect that current as well?
Update 16 March 2011.
So I designed, built and failed. Or rather, lost patience. I learned a lot though, so I am calling it a victory. A victory over my problem (I know it now, I know how to solve it, I now know my board fabricating is crap.) but also a victory over my own stubbornness.
So I caved, big deal! Here are three boards that should be able to program a uBotino. Or any Arduino that has no on board ftdi.
Two of which actually work....
From top, clockwise round:
- Home built level converter using a PNP-NPN pair of BJT's plus another PNP for auto reset feature.
- Same thing designed by professionals, soldered by me. No auto reset though.
- USB serial converter with FTDI, with auto reset feature. Requires special drivers in my OS. Comes ready made. Is tiny.
They all feature data traffic indicating LEDs.