Microcontroller User Interfaces
The intent of this page is to document different styles of user interfaces for microcontrollers together with code ( any language ) to drive them. We could use some contributions, can you help?
Contents
Input
Momentary Button
- Pro Cheap, simple, uses only 1 bit port
- Con If you use a bunch uses a lot of port bits
Rotary Switch
- Pro
- Con
Can be self decoding: position of switch indicates state of microcontroller.
Rotary Encoder
- Pro
- Con
Potentiometer
Use to feed a voltage to an analog to digitial converter. You sould be able to get quite a few discrete values out of this while still having it easy to use. Instead of a pot you can use a rotary switch with fixed resistors switched.
- Pro Uses only 1 pin if using an AtoD converter.
- Con Readint takes a AtoD converter ( or standard io port(s) with software. Takes a bit of time.
Keypad
- Pro
- Con
Output
Single Led
In its simplest form either on or off, slightly harder to read are various patterns of blinks.
- Pro
- Con
Multiple Led
- Pro Cheap, simple, easy to drive. One port bit per led ( untill you get to large numbers where ticks kick in ) Match with a pushbutton and state of the microcontroller and means to change it is simple.
- Con Can use more port bits than you have.
A shift register can make driving a large number easier.
7 Segment Led
- Pro
- Con
LCD
In the nibble mode mode needs a total of 7 port bits. Some displays are backlit, others are not.
- Pro Can have lots of characters, small displays are often 2 x 16. Cost is about 10 bucks.
- Con Cost is about 10 bucks. You may not have the 7 port bits available.
PC on Serial Port
Control with a terminal program or a custom application. PC provides both input and output.
- Pro 2 bit only. Can have very fancy smart interface. Can be very useful for debugging.
- Con Needs PC. May need custom application. For good flexibility needs a uart on the chip.
