USB motion sensor (PIR) to wake up screen
vendredi 20 juin 2014 à 10:13I have an always on net-book for weather forecast (yeah, when paragliding, you need it)
It basically displays a full screen custom web-page with time and date.
Its always on, not really good for the back-light and energy consumption.
So I got the idea of plugging a PIR sensor to wake up the screen when someone approach it.
Take an Arduino Micro Pro (8€ for the Chinese version), a PIR sensor from eBay (2€), a Hammond case (1€) and an USB A male from scrap (0€).
Let’s give a try, with a basic wiring, and this sketch to emulate keyboard thanks to it’s USB HID, the Arduino Micro Pro is a must.
int sensorPin = 10; void setup() { pinMode(sensorPin, INPUT); Serial.begin(9600); } void sendWakeUp(void); void loop() { if (digitalRead(sensorPin) == 1) { sendWakeUp(); while (digitalRead(sensorPin) == 1) { delay(1000); } } delay(1000); } void sendWakeUp(void) { Keyboard.press(KEY_LEFT_CTRL); delay(1); Keyboard.release(KEY_LEFT_CTRL); }
And voila!
Quite nice, discrete and works very well, for about 10€/$.
Note: if someone has an idea to send a key other than LEFT_CTRL (as it can be disruptive on a workstation), I’m looking for a solution.
