Thursday 19 July 2012

Prototype Hardware

The rats nest to the right is the prototype for the NRI832 hardware. Nor running actual code yet, just a testing program that takes a key from the keypad and displays its ASCII value on the LEDs (00110010 == $32, or character '2').

Despite the mess it is relatively simple. It is an Arduino Duemanolive (sic ?) - i.e. a Mega328 based Arduino. Ontop of that is a prototyping shield with a breadboard.

The LEDs are connected to ground via 8 1k Resistors and are connected to pins 10,9,A5,A4,A3,A2,A1,A0 respectively (left to right).

The keypad is a standard 3x4 keypad (almost everywhere sells them) and it is connected to 8,7,6,5,4,3,2 (left to right).

Pins 1 and 0 are NC because I used Serial Debugging at one point.

Unfortunately it is upside down. On all these trainer-type constructs the display is always above the keyboard. I used a pin strip (6 pins) and a wire to fit the keyboard (the wire because of the gap between pins 7 and 8 on an Arduino).

Most of the code is written now - the 'C' code simulates the Arduinos operation, providing functions to isolate the actual physical I/O, so I just need to glue it to this code and hopefully it should work. The C code link on the right has been updated with this new code. Not that it's very interesting :)

No comments:

Post a Comment