Objective

Learn how to create digitally controlled devices using the LogoChip and then interface these devices to the Handy Cricket using its Bus protocol.

Design

For the LogoChip lab I decided to implement a driver for the DevanTech sonars that are part of the  Botball kit.  The driver will have the LogoChip indicate distance to target in a standard unit of time.  The sonar data will be communicated to the cricket over the bus line, which the cricket is in control of.  Based on how close the target is to the sonar sensor, the cricket will emit a beep from its piezo commensurate with the target proximity.

 The LogoChip Logo code for the sonar, also known as the sonar driver is in the file sonar.txt.  This code sits quietly in the LogoChip until a request is made over the bus line, connected to pin B0 of the LogoChip, by the cricket.  The sonar is connected to pins B6 and B7 of the LogoChip.  The wiring diagram for the LogoChip  is found here.
 

The cricket code is found in the file son.txt.  It continuously sends a command over its bus to the LogoChip.  The LogoChip waits for this command and upon receiving it, it calls the sonar driver, which returns a value representative of the distance of the target from the sonars.  The LogoChip sends this value over the bus to the cricket.  The cricket emits beeps from its piezo to indicate how close the target is.
 

The resolution of the sonar data returned from the LogoChip was not very good due to the large timer values(1 ms), relatively speaking.  In the future the resolution could be improved by utilizing no-op operations.