This week we focused on output devices. An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world.
In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world. Inputs are the signals or data sent to the system, and outputs are the signals or data sent by the system to the outside.
I worked with the boards Neil provided for us. It was really exciting for these to work - hopefully next time I can tackle my own designs. Milling with the fab modules on the Modela went really well so I milled three boards.
Charlieplexing is a technique proposed in early 1995 by Charlie Allen at Maxim Integrated Products for driving a multiplexed display in which relatively few I/O pins on a microcontroller are used to drive an array of LEDs. The method utilizes the tri-state logic capabilities of microcontrollers in order to gain efficiency over traditional multiplexing. Although it is more efficient in its use of IO, there are issues that cause it to be more complicated to design and render it impractical for larger displays. These issues include duty cycle, current requirements and the forward voltages of the LEDs.
This was the first board I milled and stuffed - soldering is getting easier. This board working inspired me to give the Charlieplexed board a shot.
I hope to stuff this boad on Monday... then figure out how to use it... (Update, I ripped up a trace while soldering, I'm going to try to fix it, doesn't look good though...)