Build the Tool You Need - Serial Utility Board

Awhile back I modified a USB-to-Serial converter to be more of a USB-to-UART converter. While it was useful for a little while, I still found it to be a little clumsy to use. I wanted to make something a bit more usable.

Now there are plenty of FTDI chips out there, but I went with Microchip's MCP2200. It's a USB-to-UART device, but it also has some programmable GPIO pins that can be controlled from the PC.

For this board I wanted to address a couple needs: easy connectivity to a breadboard, serial communication at 3.3V or 5V, and providing power to my test circuits.

I combined the first and last items in the PCB layout. I designed it such that the board would span a typical breadboard's power rails, and plug directly into them. I provided jumpers to select which pins ground and power were output on so that I could also plug in along a power rail (I'll show in photos below). I also added a switch to choose between 3.3V or 5V, which is then supplied to the power output pin.

I also put in a female header to make it easy to jumper all the GPIO and TX and RX signals. The header also has dedicated 3.3V and 5V pins so that both voltages are always available to use, regardless of which is selected.

A simple enough board, but now I pretty much just leave it plugged into my breadboard all the time.  More often than not, it's providing whatever voltage I need, and I just have to connect two wires and I'm talking with the PC.