I want gather the nerdkit parts for a friend who wants to start with microcontrollers the same way I did. I can purchase everything I need except the USB cable. Since we can't purchase through nerdkits.com anymore, I tried to buy one that was based on the Prolific PL2303 chipset, but it never worked.

Where can I get a USB cable that I can use to program my ATMEGA328p?

You can use most any USB / Serial cable. I know the FTDI 5v cable that sparkfun sells, works ( Sparkfun Link ) you just have to make sure it's wired properly. With that cable, you would use the black (Ground), red(5V DC), orange(TX - connect to RX of microcontroller), and yellow (RX - connect to TX of microcontroller).

Other cables would work as well, just make sure they are 5V, and hook the TX of the cable to the RX of the micro, and RX of the cable to the TX of the micro.

While you can get these cables through ebay, you have to be careful because the FTDI chips have been counterfeited and those cables will not work. FTDI drivers will disable non-genuine chips. Sparkfun's cables are genuine and will work. I've recommended them before with success.

Rick

Per nerdkits.com:

"To allow you to program and talk to your USB NerdKit microcontroller over USB, we make use of a USB to Serial adapter (included with the kit). This adapter is based on the Prolific PL2303 chipset. This page summarizes driver compatibility for various operating systems."

Then the members download page has a link to download the "PL2303 USB-serial drivers." Will this driver work with the Sparkfun cable you recommended? If not, do you have a link to Windows (and even MAC OS X) drivers you'd recommend?

Sparkfun has a link to FTDI for drivers for windows, mac, and linux in many flavors. You don't need a PL2303 to communicate to the "Nerdkit". Keep in mind, the Nerdkit is nothing more than an Atmel microcontroller with a generic serial bootloader installed. The microcontroller doesn't care what brand chipset is on the USB to serial converter. I've used FTDI, CP2102, and prolific chipsets all with success.

Rick

Excellent, thank you so much, Rick!

I got the one you recommended from Sparkfun. Sparkfun also provides a doc for downloading and installing the driver. When I plugged in the cable, it showed up as COM11 and avrdude couldn't open it. I found a post online that said to view the COM11 port in the Windows device manager (I'm on Win7) and go to the advanced settings to change the port from COM11 to COM1. I did it and it worked perfectly.

Again, I appreciate the help!

Also, thanks for the wire assignments above also. Just for anyone reading this later, the MCU's pin 2 is Rx and pin3 is Tx. So, putting that together with what Rick spells out above:

BLACK = GND,
RED = +5V
ORANGE = MCU Rx (Pin 2)
YELLOW = MCU Tx (Pin 3)