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