1 | /*
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2 | Running shell commands using Process class.
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3 |
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4 | This sketch demonstrate how to run linux shell commands
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5 | using an Arduino Y炭n. It runs the wifiCheck script on the Linux side
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6 | of the Y炭n, then uses grep to get just the signal strength line.
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7 | Then it uses parseInt() to read the wifi signal strength as an integer,
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8 | and finally uses that number to fade an LED using analogWrite().
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9 |
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10 | The circuit:
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11 | * Arduino Y炭n with LED connected to pin 9
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12 |
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13 | created 12 Jun 2013
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14 | by Cristian Maglie
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15 | modified 25 June 2013
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16 | by Tom Igoe
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17 |
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18 | This example code is in the public domain.
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19 |
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20 | http://arduino.cc/en/Tutorial/ShellCommands
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21 |
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22 | */
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23 |
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24 | #include <Process.h>
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25 |
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26 | void setup() {
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27 | Bridge.begin(); // Initialize the Bridge
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28 | Serial.begin(9600); // Initialize the Serial
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29 |
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30 | // Wait until a Serial Monitor is connected.
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31 | while (!Serial);
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32 | }
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33 |
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34 | void loop() {
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35 | Process p;
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36 | // This command line runs the WifiStatus script, (/usr/bin/pretty-wifi-info.lua), then
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37 | // sends the result to the grep command to look for a line containing the word
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38 | // "Signal:" the result is passed to this sketch:
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39 | p.runShellCommand("/usr/bin/pretty-wifi-info.lua | grep Signal");
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40 |
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41 | // do nothing until the process finishes, so you get the whole output:
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42 | while (p.running());
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43 |
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44 | // Read command output. runShellCommand() should have passed "Signal: xx&":
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45 | while (p.available()) {
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46 | int result = p.parseInt(); // look for an integer
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47 | int signal = map(result, 0, 100, 0, 255); // map result from 0-100 range to 0-255
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48 | analogWrite(9, signal); // set the brightness of LED on pin 9
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49 | Serial.println(result); // print the number as well
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50 | }
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51 | delay(5000); // wait 5 seconds before you do it again
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52 | }
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53 |
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54 |
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55 |
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