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Diffstat (limited to 'libraries/Bridge/examples/WifiSignalStrengthIndicator')
-rw-r--r-- | libraries/Bridge/examples/WifiSignalStrengthIndicator/WifiSignalStrengthIndicator.ino | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/libraries/Bridge/examples/WifiSignalStrengthIndicator/WifiSignalStrengthIndicator.ino b/libraries/Bridge/examples/WifiSignalStrengthIndicator/WifiSignalStrengthIndicator.ino new file mode 100644 index 0000000..e0b2d1f --- /dev/null +++ b/libraries/Bridge/examples/WifiSignalStrengthIndicator/WifiSignalStrengthIndicator.ino @@ -0,0 +1,112 @@ +/* + Wifi Signal Strength Indicator + + This example demonstrates the use of the bridge and process libraries + to communicate between the Arduino side and the linux side of the Arduino Yun. + + The Linux script returns the strength of the wifi signal. + + The Arduino sketch uses LEDs to indicate whether the current value of + the signal strength is above, below, or the same as the last value + + The circuit: + * LEDs on pins 8, 9, and 10 + * Built-in LED on pin 13 + + The script: + The following one line script must exist in the /root directory of the + linux file system, in a file named "wifiStrength.sh", and it must be executable: + + tail -1 /proc/net/wireless | cut -c22-23 + + created 06 June 2013 + by Michael Shiloh + modified 08 June 2013 + by Tom Igoe + + This example code is in the public domain + + */ + + +#include <Process.h> + +// global variable to store the last value of the signal strength +int lastValue; + +void setup() { + // set up LED pins as outputs: + pinMode(8, OUTPUT); + pinMode(9, OUTPUT); + pinMode(10, OUTPUT); + pinMode(13,OUTPUT); + + // Indicate that you're ready by flashing pin 13 LED twice + for (int flash = 0; flash < 3; flash++) { + digitalWrite(13,HIGH); + delay(200); + digitalWrite(13,LOW); + delay(800); + } + // initialize Serial and Bridge: + Serial.begin(9600); + Bridge.begin(); + + // Indicate that setup is finished + digitalWrite(13,HIGH); +} + +void loop() { + int value = 0; // the signal strength as an integer + String result; // the result of the process as a String + Process wifiCheck; // the process itself + + + // Run the script on the linux side. Note that any word + //or text separated by a tab or space is considered + //an additional parameter: + wifiCheck.begin("ash"); + wifiCheck.addParameter("/root/wifiStrength.sh"); + wifiCheck.run(); + + // If the process has sent any characters: + while (wifiCheck.available()>0) { + result = wifiCheck.readString(); // read the result into a string + value = result.toInt(); // parse the string as an int + } + + // for debugging + Serial.print("previous strength:"); + Serial.print(lastValue); + Serial.print("\tcurrent strength:"); + Serial.println(value); + + // indicate the relative string by lighting the appropriate LED + allOff(); // turn off all the LEDS + + if (value > lastValue) { // if the signal's getting stronger + digitalWrite(10, HIGH); + } + else if (value < lastValue){ // if the signal's getting weaker + digitalWrite(8, HIGH); + } + else { // if the signal's stayed steady + digitalWrite(9, HIGH); + } + + lastValue = value; // record this value for next time + delay(10); // small delay before next time through the loop +} + + +void allOff() { + digitalWrite(8, LOW); + digitalWrite(9, LOW); + digitalWrite(10, LOW); +} + + + + + + |