From Fred Parrett - USB-12 bit DAC project
Using Visual Basic or C# for PC control of USB I2C adaptor connected to 12 bit DAC breakout board.
Stage 1 of project - send increasing 12 bit value (0 to 4095 - equiv to 0-5v) to DAC breakout board every second until stopped by mechanical switch connected to the I2C Adpator. Hold at voltage when stopped.
Components - these would be supplied by post free of charge
USB-ISS adaptor (from [url removed, login to view])
- this enables I2C control via SDA/ SCL and also has 2 digital I/O ports.
MCP4725- 12 bit I2C DAC breakout board (from [url removed, login to view])
- or UK distributor
Simple tactile momentary on switch
Programming to be done in Visual Basic Express 2010 - or Visual C# express 2010.
1. Drop down box to Select COM port (show in label box)
2. Start Voltage increase ( show 12 bit number & voltage output in lable boxes)
3. Stop and hold Voltage (note: voltage can also be stopped by external mechanical switch)
Note: there are a number of example C# programs on the robot-electronics web site, but not much of help on the sparkfun web site.