ft232 breakout board (newbie)

I took the chip (atmega168) and put it on a breadboard and wired it up according to the tutorial at ITP Physical computing. I added on an FT232 breakout board and kind of hoped when I plugged it into my computer it would allow me to upload sketches just as I do when the chip is in my Duemilanove board. But I get the following meassage:

avrdude: stk500_getsync(): not in sync: resp=0x30 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

I've read there isn't an obvious fix when you get this message. But can anyone help. I've checked all my wiring fifty times. I am using a 16Mhz resonator rather than the crystal and capacitors but I don't see what difference that would make. The chip is bootloaded as it's the one out of my original arduino board. And the sketch already on the chip works fine.

Sorry if this is really basic but I tried everything I can think of.

Its probably because your FT232 board and/or breadboard setup haven't implement the auto reset feature of the standard Adruinos. It requires the DTR signal from the RS232 chip and a capacitor / resistor arrangement on the reset of the AVR. Lacking this you need a reset button on your breadboard which you press at an appropriate time whilst uploading a sketch. Never needed to do it, but apparently timing is critical............

When properly wired an external USB board and a DIY arduino behave exactly as the pucca item when uploading sketches.


So can anyone tell me about the timing. I have the reset button on pin one of the 168.

Something of a lost art, the old arduinos needed to be done manually with the reset, but they had a long timeout so the timing wasn't critical. Modern ones have short timeouts so the sketch starts quicker but they have automatic reset. I've never done it myself (I wire up the reset circuit) but I beleive pressing reset just after the IDE reports the sketch size at the beginning of the upload process is about right. Somebody may have done it with a modern Arduino who knows better.

Can you tell me where I can see a copy of the reset circuit?


Assuming you already have a switch and 10k pullup resistor for the reset circuit on your breadboard, its just a matter of a 0.1uF (100nF or 104) ceramic capacitor between the DTR line on your USB board and the reset pin on the AVR chip. Couldn't be simpler really, but its a pain if your board doen't bring out the DTR line.

When the DTR line goes low, it drags the reset line line low briefly against the pullup resistor and resets the Arduino which then starts the upload of the sketch.

It worked! Thank you so much. This has been driving me nuts. Thank you thank you thank you.