userial
Index ¶
Description ¶
userial is a project building a free USB to I2C/SPI/GPIO bridge, using the Atmel AT90USB647 chip. Hardware and Software are released under an Open Source licence. It supports the following interfaces:
- 1 × USB interface (serial emulation)
- 1 × JTAG interface
- 1 × I2C (TWI)
- 1 × SPI
- 8 × General purpose digital I/O
- 4 × Analog to Digital converters
The board communicates with the host computer using a CDC (USB communications device class). This makes it easy to use userial without installing a device driver or special libraries. Due to the ASCII based command interface it is easy to control devices manually with just a terminal emulation. This makes it easy to obtain quick results, to configure devices on-the-fly or to control prototyping boards in a straight-forward way.
Schematics and firmware are available to the public. The firmware is released under the terms of the MIT license and the hardware is released under the terms of the Creative Commons Attribution-Share Alike 3.0 Unported License.
Documentation ¶
Download ¶
- Firmware (v1.9, compatible with userial hardware v1.0 and the Bumble-B board)
- Schematic as PDF (v1.0)
- Schematic as PNG (v1.0)
- Eagle source files (v1.0)
- Gerber files (v1.0)
If you don't want to build your own hardware, then you might find the Bumble-B board from Fletchtronics worth a look. It is a rather inexpensive board based on the AT90USB162 chip and is supported by userial firmware as of version 1.9.
News ¶
Firmware v1.9 (25 March 2010)userial firmware v1.9 released. The changes in this version are:
- Updated LUFA to version 100219.
- Added support for bumble-b board.
- The actual SPI clock divider was never written to the clock divider. Thanks to Erik Schönewerk.
- Fixed a bug in the GPIO driver: the GPIO read command returned the value of PORTx but not PINx. Thanks to Dave Fletcher.
Firmware v1.8 (31 October 2009)
userial firmware v1.8 released. The changes in this version are:
- Fixed a bug in the calculation of the SPI frequency divider. Thanks to Zoran Stojkovic.
Firmware v1.7 (26 September 2009)
userial firmware v1.7 released. The changes in this version are:
- Updated LUFA to version 090924.
- Added ADC support. Many thanks to Zoran Stojkovic.
- Added compile switches to selectively turn off features.
Bumble-B (12 September 2009)
fletchtronics.net sells a board called Bumble-B and has ported userial to the the AT90USB162 processor.
Firmware v1.6 (28 February 2009)
userial firmware v1.6 released. The changes in this version are:
- Added new command 'IX' for a I2C bus clear.
- Fixes a bug in the USB transmit task: when userial was transmitting 16 bytes on the USB bus, the data was kept in the transmit buffer until the next command.
All news can be read in the userial news archive.