Next in our series of articles about analogue/digital signal conversion comes another great project from the Fritzing showcase. User 'itead' has made an effective 8-bit digital to analogue converter once again using the R/2R resistor ladder method. By using 1% tolerance or less resistors the results can be quite accurate, for example:
From a software perspective the designer has created an array of values from 0 to 254 which when converted to binary can match the digital outputs used to create the particular output voltage from the DAC. These values are then sent using port manipulation to set the respective digital output pins HIGH or LOW. For more information including sketch and design, check out the project page. And we're on twitter and Google+, so follow us for news and product updates as well.
As we always say, when making your own DAC, you'll need a protoshield to mount the external circuitry. In doing so, consider our range of ProtoShields. From the tiny LeoStick to the Mega range, we offer a complete range for you to work with.