1.0 Introduction

The Controller28 module is the master module and controls the activities of the other (slave) modules connected to the CAN bus.  Many of the 28 pin PIC microchips and Atmel microprocessors will work with this module but in most of this section the PIC18F2620 will be the microcontroller of choice.  Code and other examples are easily ported between PICs.

2.0 Revision Details

The historical detail of the revisions between subsequent versions of this brick will be detailed here.  Only revisions that create differences in the operation, programming or hookup of two modules with different revison numbers will be documented.

Rev C to Rev D - Rev D versions allow for use of either the Atmel Microprocessor or the Microchip PIC.  Earlier versions accommodate only the PIC microcontroller.

3.0 Hookup Details

The photo below labels the various headers and switches which are detailed on the Controller28 (Rev D) circuit diagram. 

4.0 Selection of Power Source:

4.1 Bus Power

Bus Power (+6 to +14 volts dc) is connected to the CAN bus cable at (N5).  This provides unregulated power for use by high current devices such as servos and IR detectors..  The Bus Power voltage is isolated from the Digital Power that runs the RoboBricks2 logic (some devices such as Servo4 also provide for on-brick isolation of the Digital and Bus power supplies so that operation of the device will not interfere with the brick's logic functions).  

The Servo4 module is a case in point because the power needed to drive the servos is not supplied by the digital power used to power the Servo4 logic.   In this case, attaching a +6 volt battery to N5 on the Controller28 module will provide an unregulated and isolated power source via the CAN bus to drive the servos attached to the Servo4 module.

4.2Digital Power

The Digital Power (+5.25 to +12 Volts dc) is connected to the brick via N4.  The Controller28 conditions this power to provide a regulated +5 volts source for the logic circuits of all of the RoboBrick2s connected to the CAN.  When using power greater than 10 volts, a heat sink should be affixed to the voltage regulator to improve heat dissipation.