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53 lines
1.6 KiB
C++
53 lines
1.6 KiB
C++
/*
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Running shell commands using Process class.
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This sketch demonstrate how to run linux shell commands
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using a YunShield/Yún. It runs the wifiCheck script on the Linux side
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of the Yún, then uses grep to get just the signal strength line.
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Then it uses parseInt() to read the wifi signal strength as an integer,
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and finally uses that number to fade an LED using analogWrite().
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The circuit:
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* YunShield/Yún with LED connected to pin 9
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created 12 Jun 2013
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by Cristian Maglie
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modified 25 June 2013
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by Tom Igoe
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This example code is in the public domain.
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http://www.arduino.cc/en/Tutorial/ShellCommands
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*/
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#include <Process.h>
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void setup() {
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Bridge.begin(); // Initialize the Bridge
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SerialUSB.begin(9600); // Initialize the Serial
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// Wait until a Serial Monitor is connected.
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while (!SerialUSB);
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}
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void loop() {
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Process p;
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// This command line runs the WifiStatus script, (/usr/bin/pretty-wifi-info.lua), then
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// sends the result to the grep command to look for a line containing the word
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// "Signal:" the result is passed to this sketch:
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p.runShellCommand("/usr/bin/pretty-wifi-info.lua | grep Signal");
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// do nothing until the process finishes, so you get the whole output:
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while (p.running());
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// Read command output. runShellCommand() should have passed "Signal: xx&":
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while (p.available()) {
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int result = p.parseInt(); // look for an integer
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int signal = map(result, 0, 100, 0, 255); // map result from 0-100 range to 0-255
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analogWrite(9, signal); // set the brightness of LED on pin 9
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SerialUSB.println(result); // print the number as well
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}
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delay(5000); // wait 5 seconds before you do it again
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}
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