Get tutorials Raspberry Pi Sensor Kit V2.0 for Raspberry Pi B+

Lesson 7 Tilt-Switch Module

Introduction

The tilt-switch module (as shown below) in this kit is a ball tilt-switch with a metal ball inside. It is used to detect inclinations of a small angle.


 


Components

- 1 * Raspberry Pi

- 1 * Breadboard

- 4 * Jumper wires (Male to Male, 2 red and 2 black)

- 1 * Network cable (or USB wireless network adapter)

- 1 * Dual-color LED module

- 1 * Tilt-switch module

- 2 * 3-Pin anti-reverse cable

 

Experimental Principle

The principle is very simple. The ball in the tilt-switch changes with different angle of inclination to trigger the circuit. When the ball in tilt switch runs from one end to the other end due to shaking caused by external force, the tilt switch will conduct and the LED will emit red light, otherwise it will break and the LED will emit green light. The schematic diagram of the module is as shown below:


 


Experimental Procedures

Step 1: Build the circuit


Raspberry Pi

T-Cobbler

Tilt Switch Module

GPIO0

GPIO17

SIG

5V

5V0

VCC

GND

GND

GND

 

Raspberry Pi

T-Cobbler

Dual-Color LED Module

GPIO1

GPIO18

R

GND

GND

GND

GPIO2

GPIO27

G

 

 

For C language users:

Step 2: Change directory

 cd /home/pi/SunFounder_SensorKit_for_RPi2/C/07_tilt_switch/

Step 3: Compile

gcc tilt_switch.c –lwiringPi

 

Step 4: Run

sudo ./a.out


For Python users:

Step 2: Change directory

 cd /home/pi/SunFounder_SensorKit_for_RPi2/Python/

Step 3: Run

sudo python 07_tilt_switch.py


Place the tilt switch module horizontally, and the LED will flash green. If you tilt it, "Tilt!" will be printed on the screen and the LED will change to red. Place it horizontally again, and the LED will flash green again.



C Code


#include <wiringPi.h>
#include <stdio.h>

#define TiltPin		0
#define Gpin		1
#define Rpin		2

void LED(char* color)
{
	pinMode(Gpin, OUTPUT);
	pinMode(Rpin, OUTPUT);
	if (color == "RED")
	{
		digitalWrite(Rpin, HIGH);
		digitalWrite(Gpin, LOW);
	}
	else if (color == "GREEN")
	{
		digitalWrite(Rpin, LOW);
		digitalWrite(Gpin, HIGH);
	}
	else
		printf("LED Error");
}

int main(void)
{
	if(wiringPiSetup() == -1){ //when initialize wiring failed,print messageto screen
		printf("setup wiringPi failed !");
		return 1; 
	}

	pinMode(TiltPin, INPUT);
	LED("GREEN");
	
	while(1){
		if(0 == digitalRead(TiltPin)){
			delay(10);
			if(0 == digitalRead(TiltPin)){
				LED("RED");
				printf("Tilt!\n");
			}
		}
		else if(1 == digitalRead(TiltPin)){
			delay(10);
			if(1 == digitalRead(TiltPin)){
				while(!digitalRead(TiltPin));
				LED("GREEN");
			}
		}
	}
	return 0;
}



Python Code


#!/usr/bin/env python
import RPi.GPIO as GPIO

TiltPin = 11
Gpin   = 12
Rpin   = 13

def setup():
	GPIO.setmode(GPIO.BOARD)       # Numbers GPIOs by physical location
	GPIO.setup(Gpin, GPIO.OUT)     # Set Green Led Pin mode to output
	GPIO.setup(Rpin, GPIO.OUT)     # Set Red Led Pin mode to output
	GPIO.setup(TiltPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)    # Set BtnPin's mode is input, and pull up to high level(3.3V)
	GPIO.add_event_detect(TiltPin, GPIO.BOTH, callback=detect, bouncetime=200)

def Led(x):
	if x == 0:
		GPIO.output(Rpin, 1)
		GPIO.output(Gpin, 0)
	if x == 1:
		GPIO.output(Rpin, 0)
		GPIO.output(Gpin, 1)

def Print(x):
	if x == 0:
		print '    *************'
		print '    *   Tilt!   *'
		print '    *************'

def detect(chn):
	Led(GPIO.input(TiltPin))
	Print(GPIO.input(TiltPin))

def loop():
	while True:
		pass

def destroy():
	GPIO.output(Gpin, GPIO.HIGH)       # Green led off
	GPIO.output(Rpin, GPIO.HIGH)       # Red led off
	GPIO.cleanup()                     # Release resource

if __name__ == '__main__':     # Program start from here
	setup()
	try:
		loop()
	except KeyboardInterrupt:  # When 'Ctrl+C' is pressed, the child program destroy() will be  executed.
		destroy()







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Next chapter: Lesson 8 Vibration Switch

SunFounder
Apr 14 2017 at 08:58 am



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