Difference between revisions of "Example mcp4922 test"

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(Using mcp4922_test)
(Using mcp4922_test)
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  ./mcp4922_test
 
  ./mcp4922_test
  
Regard the HDR8 ANALOG I/O HEADER on your EMAC SoM-150ES carrier board.  
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Regard the EMAC SoM-150ES carrier board. Locate the HDR8 ANALOG I/O HEADER (circled).
  
<pic of header>
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[[File:hdr8_analog_io_header_location.jpg]]
  
 
Pin 15 is analog out 0 and pin 16 is analog out 1. Pins 1, 2, 17 and 18 are all ground.  
 
Pin 15 is analog out 0 and pin 16 is analog out 1. Pins 1, 2, 17 and 18 are all ground.  

Revision as of 11:42, 31 December 2013

TODO: {{#todo:InProgress(11.14.13-15:09->JG+)|Jgreene|oe 4,oe 5,jg,md,InProgress}}

This is a guide to the mcp4922_test C example project included in the EMAC OE SDK.

This is an example application for accessing the EMAC interface for the on-board DtoA of the SoM-150ES. This interface uses the EMAC ioex class to provide a GPIO-like interface (see also the egpc project). This application outputs a sine wave on channel 0 and a cosine wave on channel 1.

The mcp4922_test project builds one executable: mcp4922_test.

Opening, Building and Uploading the Project Files

1. Open the C/C++ editing perspective.

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2. Open the project files.

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3. Build the project.

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4. Upload the executables to the target system.

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Usage and Behavior

mcp4922_test outputs a sine wave on channel 0 and a cosine wave on channel 1.

Hardware Requirements

The mcp4922_test C example project requires an EMAC SoM-150ES carrier board.

Using mcp4922_test

Run it from the console...

./mcp4922_test

Regard the EMAC SoM-150ES carrier board. Locate the HDR8 ANALOG I/O HEADER (circled).

Hdr8 analog io header location.jpg

Pin 15 is analog out 0 and pin 16 is analog out 1. Pins 1, 2, 17 and 18 are all ground.

Hdr8 analog io header detail.jpg

When we execute mcp4922_test we get a 5v sine signal on pin 15 and a cosine on pin 16. We can watch the signals on an oscilloscope or listen to them on a speaker.