More pixs
A UNO stick made with the rancidbacon reference circuit. The USB-Serial converter is fitted to the board for programming via the Arduino GUI and then removed. Alternately, the uC could be removed and flashed with any ISP burner (generally overwrites bootloader, however.)
The strip of protoboard was from Radio Shack... old stock: 910-3804 DIP-Small
The USB-serial adapter is from eBay. I have cut the 3.3V line and the Reset line (not an Arduino reset.) One adapter can be used with many sticks... no reason to throw $2.20 U.S. to the wind to dedicate a serial-USB since the HID connector will provide for serial output. Yes, you could run both USB ports simultaneously (but only use HID +5 and do not connect the CP21xx +5... only Ground reference, Tx, and Rx. Such a configuration could be used to use the Com-USB port for eeprom configuration, customization menu, sensor offsets, one-time keyboard input, etc. and all the pertinent user output could come over HID. Or, the Com serial could be used for diagnostics, etc.
The key takeaway is that USB-Com requires an INF and driver for Windows but HID keyboard is accepted without user driver installation... the OS will load native drivers automatically under Windows, Linux, iOS... even some tablets with USB support.
I did cover the bottom of the hand-soldering of parts with HFT quick setting epoxy to allow the stick to be handled without fear of being overly gentle.
- Ray
