HalNodes operate on data streams. Data streams are arbitrary sequences of 8 bit binary integers. Data streams end at HalNodes and originate at HalNodes. 4 mHz HalNodes can get new inputs in about 500 microseconds and put out a new datum in the same time interval.

This specification is addressed to those who build sensors of all kinds to sense the outside world and those who build actuators, motors and so on to act on the outside world.

For 8 bit (note 1)

Data streams are carried physically on standard 4 wire flat cable. 4 pin IDC plugs are positioned on the cable where required. These plug into 4 pin sockets on the HalNodes or on your nodes.

Pin Name   Function                 Headers
1   5V     6 to 4 volts for numeric 1 2
2   Ground ground for all           3 4
3   control   
4   Data

                             
Pin 1 orientation should be observed but boards will not be zapped if cables are reversed. Pin 1 is always toward top of board.

Use 4 conductor cables, plugs and sockets.
Each sensor and motor has a socket like this. Pins match numeric nodes where applicable.

Sensors Pin Name Function     header (top)
1 A5v Power 4 to 6 volts         1 2
2 Ground Ground from numeric     3 4
3 Signal 1 Signal voltage
4 Signal or ground

Motors H Pin Name Function (H-Bridge)
1 NC
2 NC
3 V1 Voltage 1
4 V2 Voltage 2

Motors S Pin Name Function (Servo)
1 A5V Power
2 Ground Ground
3 Signal Timed signal
4 NC

Comments, questions, suggestions will be appreciated. Hardware is
available.

Note 1: The same hardware accommodates 1, 2, 4, 8, 16, 32...,any power of 2 number. This is done in software and must hold system wide. That means to be careful of mixing multi base nodes. For now, everything is 8 bits, giving a base 256 number.

Copyright 2004, Harold L. Reed