Data Logging Part 2 - A User Interface

My first attempt at a micro controller user interface -

I am pretty happy with it, its a thousand times better than the horrible interfaces you get on your average Electronic Speed Controller. Take the example of a Tamiya TEU104BK, the user interface consists of a single 1*2 mm grey button hidden in a 4mm recess in the case. The button and indicator light are in highlighted area in the pic below, a 10mm push button is included for size comparison.

While I have used a great big bright red 10mm push button, I haven't completely broken away from tradition, the interface still relies on the users ability to count and interpret a sequence of flashing lights. The reason for this is that mirco controllers provide a limited number of inputs and outputs. Each of these inputs/outputs can be extremely powerful so using them up with indicators, displays and multiple push buttons is an unacceptable waste of resources.

The data logger user interface


1 Big Red 10mm Push Button
1 Bright Red LED to signal 'Recording'
1 Bright Green LED to signal 'Sending recorded data over the serial interface'

The system has 5 states -

State	Meaning	Record Indicator	Serial Indicator
Idle	Not currently doing anything	Brief flash every 2 seconds	As Record
Record	Recording Data to SD Card	On	Off
Serial	Reading SD Data and writing to serial	Off	On
Memory Full	No more data can be recorded	On 1 Second/Off 1 Second	As Record
Error	Something is wrong	Rapid Alternate with Serial	Rapid Alternate with Record

To move between states the push button must be held for 1 second or more. To enter record from idle 1 Second, to enter Serial from idle 4 Seconds, to exit either record or idle 1 second.

All I need now is a Micro SD Card and the data logger is up and running.