Example io demo

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TODO: {{#todo:InProgress(11.19.13-15:28->JG+)|Jgreene|oe 4,oe 5,jg,md,Review}}

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

IO is an acronym standing for Input Output. It refers to data going in and data coming out. In and out of what you ask? Why your machine of course. In this case your machine is the SOM-150ES carrier board.

Input is data going into your machine. Your machine is receiving data, via a port or header, from an external piece of hardware. Mouses, joysticks, keyboards, electronic rain-guages, digital telescopes, burglar alarms and the internet: these all produce streams of data that your machine can store, process, fold, weave and/or otherwise react to. What your machine does with the data, specifically, depends what software you've got running. The io demo is an example of such software.

Output is data coming out of your machine. Your machine is sending data, via a port or header, to an external piece of hardware. It's telling that piece of hardware to do something: store some bytes of data, blink an LED, wiggle a robotic tentacle... The data sent depends on what software you have running. The io demo is an example of such software.

Combined, that's IO. It's how your machine converses with the world outside it's solipsistic silicon village. Without it your spendy machine is little more than a sexy paperweight.

The io demo gives us four nice demonstrations of SOM-150ES carrier board IO. We keep it simple. As you might imagine there are some extremely sophisticated IO technologies out there (USB, Ethernet...) but that's a discussion for another time. Here we're just going to work with our general-purpose input-output header: a double row of 50 pins that can read or render a binary value. It's straightforward stuff. Understanding the principals outlined here will equip you to hold meaningful digital conversations with anything from a toaster to a space shuttle.

Opening, Building and Uploading the Project Files

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

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2. Open the io demo project files.

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3. Build the io demo project.

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4. Upload the io demo binary to the target machine.

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Description, Usage and Expected Behaviour

This is a demo program illustrating how to access different SOM-150ES carrier board io. To use this program you will need a SOM-150ES carrier board.

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SOM-150ES carrier board

Usage for io_demo

io_demo

Running the program brings up a menu of demos.
i2c menu
Press a,c,i or r to run a demo. Press x to exit.

A/D Demo

File:Io demo terminal session sample 0.png

Count Demo

Refer to the SOM-150ES carrier board surface mount LEDs LD1-LD8 for output.

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The board counts from 0 to 15 in binary, reflecting the steps of this operation in the LEDs. When it's finished LD1 and LD6 are lit.

Input to Output Demo

Refer to the SOM-150ES carrier board surface mount LEDs LD1-LD8 for output.

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The board lights all 8 LEDs.

Ring Demo

Refer to the SOM-150ES carrier board surface mount LEDs LD1-LD8 for output.

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The board lights the LEDs in numeric sequence, 1-8, then repeats; looping until a key is pressed.