Hello, I’m following the guide here at http://itp.nyu.edu/physcomp/Tutorials/ArduinoBreadboard in order to add USB functionality to my stand-alone arduino and it doesn’t work. First, I thought it might have been the 18.43 Mhz crystal I was using since it wasn’t 16 Mhz, so I bought the only 16 Mhz anything I could find and it was a “canned oscillator” which has 4 pins. After arduously looking for the datasheets(for the chip and the crystal), I finally hooked it up and the circuit ran like it’s supposed to but the USB doesn’t work! Anyways, here’s their picture and mine afterwards.
(Right click and select “view picture” or some equivalent to view it fully.)
Sorry for the mess, but it was originally that way. It’s used to run an electric scooter, so it’s kind of complex. Just ignore all the other wires that don’t connect the crystal and sparkfun FT232R breakout board to the arduino chip and you’ll be fine.
I plugged it in, made sure I had the correct port by checking the device manager, tried to upload the program and… nothing. Well, actually, the USB device’s Red TX LED will blink 3 times with half second pulses, and then there’s a 7-9 second wait, and it’ll blink once more and then I get the inevitable error message:
avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51
Which seems synonymous with, “There’s a problem”. It seems that this error message can correspond to many different types of problems, so I don’t find it particularly helpful(Well, basically, if the arduino doesn’t receive the signals in the way it’s supposed to, it’ll get this message so I’ve found. I’ve accidentally inserted the chip backwards into the IC socket on the arduino dev board and I got the same error message.)
So, any ideas? The circuit seems to work like it originally designed, so it appears the canned oscillator is working and I can’t help but think it’s reliably sending a 16mHz clock signal, so I thought it was the breakout board. After comparing the two pictures above for many times, I arrived to the conclusion: They’re identical. I even went back to the drawing board and physically compared datasheets just to make sure the tutorial had it correct! Anyways, the circuit’s positive rail is indeed 5 volts so no problems there. And it appears I soldered the header pins correctly since it’s conducting. Suspecting the breakout board might have been bad, I soldered another one together and kept a hawk eye on the temperature of the chip using a thermometer I had and it had the same problems. Interestingly, if I disconnected all the wires from the breakout board but leave the USB cord attached, the LEDs light up in the same sequence, so it doesn’t seem the TX/RX leds are particularly helpful.