1.0 Introduction

The IO8 module provides eight  selectable input/output ports each of which can be independently configured. The port pins can be digital input, digital output, or analog input. The analog input pins can measure up to 10 bits resolution between 0 and 5 volts.  

This module is an ideal solution for robot bump sensors and IR sensors.  Bump sensors would use ports configured as digital inputs while the IR sensors could use ports configured as either digital or analog inputs.  A port configured as a digital output can be used to light LEDs or to signal another device to begin or stop operation. 

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 revision numbers will be documented.

Rev C  - Rev C changed the physical position of the eight I/O ports. 

3.0 Hookup Details

While the pin assignments for each of the eight Input/Outputs ports are identical each port can be independently configured as a digital input, digital output or analog input.  The pinout for a typical port is shown below: 

3.1  Managing Unused Ports:

There may be times when an IO8 port will not be used.  If that occurs, there are two alternatives for managing the unused port: 1) leave it unconnected i.e. let it "float" or 2) tie it either to ground or a + 5 volt source using a 1K ohm pull-down or pull-up resistor.  The easiest solution is to let the port "float" but, in this condition,  if the pin is configured as a "input" the IO8 will return unreliable values for the port's status.  The returned values can easily be masked off in software however.  While not the most elegant solution, the "float" method is preferred because it eliminates the chance that an unused pin was accidentally tied high or low without including the current limiting resistor.      

4.0 Assigned Address

The IO8 has an assigned address of "0x08" but the user can reassign a different address using the Address_Set command  so long as the user assigned address is not being used by any other module connected to the CAN bus (see RoboBricks2 - General Information and/or Common Protocol ).

5.0 Default Settings

The IO8's default configuration sets all eight ports to the digital input mode.

6.0 Operational Notes

The IO8 ports can be configured as either a digitial input or output or as an analog input.  selecting a port config; setting port direction; how the analog function works. etc. 

7.0  Programming Hints

• IO8 Programming Command Table