Sensors Simple API

What are Sensors?

Sensors are small electronic devices used measure an enviornmental quantity (for eg: temperature, pressure..)

List of features implemented in Shunya stack

With Shunya stack you can Measure these enviornmental Changes

1. Voltage
2. Light Intensity
3. Distance
4. Heart Rate
5. Liquid Flow
6. Motion Thershold
7. Proximity Threshold
8. Touch Threshold
9. Light Thershold
10. Tilt Thereshold
11. Generic Digital pin

List of Sensors supported by Shunya stack

Class	Sensor	Image	Sensor ID
Voltage
	PCF8591		6
	ADS1115		18
Light Intensity
	BH1750		7
Distance
	HCSR04		8
Heart Rate
	SEN11574		9
Liquid Flow
	YFS201		10
Motion Thershold
	PIR		11
Proximity Threshold
	IR Proximity sensor		12
Touch Threshold
	Touch Sensor		13
Light Thershold
	Light Blocking Sensor		14
Tilt Thereshold
	KY_017		15
	KY_025		16
	BALL_SWITCH		17
Generic Digital pin
	Any GPIO sensor	--	--

Using Sensors with Shunya stack

Requirements to use Sensors with Shunya stack

1. Shunya OS installed (supported Arm devices)
2. Respective Sensors connected to the supported Arm device

Steps to use Sensors with Shunya stack

1. Connect Sensors to your board.
2. Set Sensor settings in Shunya.
3. Read from sensor to get the desired value.

note

Run the steps given below inside Shunya OS installed (supported Arm devices)

Step 1: Connect Sensors to your board

1. A quick search on Google will lead to images of the connection daigrams for each sensor.
2. Note down which Sensor pin is connected to pin on the Device.

Step 2: Set Sensor settings in Shunya.

Set Sensor settings, by editing the config file /etc/shunya/interfaces/config.yaml inside Shunya OS.

A simple configuration should Tells Shunya OS your hardware connections.

Sensor ID's and Connection ID's

You tell all your Hardware connections to Shunya OS via Sensor ID's and Connection ID's.

note

There is no need to tell Shunya OS the Power connections i.e Vcc and GND. Shunya OS assumes that those are connected to the respective Pins for sensor to work.

Each Sensor is given a special ID which the Shunya OS library recognizes. And each Hardware pin on the Sensor is given a Connection ID.

So when we write pin 1: 1.1 Shunya OS understands it as <Sensor 1>.<Sensor pin 1> connected to pin 1 of Raspberry Pi(or your chosen device).

For Example: Let's say we have connected 2 devices to the Raspberry Pi (BME280 and PCF8591) to pin 3 (SDA) & pin 5 (SCL) respectively.

The Config file will look like this.

pin 3: [1.1, 6.1]
pin 4: null
pin 5: [1.2, 6.2]

tip

The configuration file allows you to quickly change the Sensors whithout changing the code.

Step 3: Read from sensor to get the desired value.

1. Start with an ready to use template for building with shunya stack

   git clone https://gitlab.iotiot.in/repo-public/examples.git
   cd examples/template

2. Open the main.cpp in an text editor and modify as per your use case.

   Example main.cpp file:

   /* --- Standard Includes --- */
   #include <iostream>
   #include <cstdlib>
   #include <stdint.h>
   #include <time.h> 
   #include <unistd.h>
   
   /* --- RapidJSON Includes --- */
   /* MANDATORY: Allows to parse Shunya AI binaries output */
   #include "rapidjson/document.h"
   #include "rapidjson/writer.h"
   #include "rapidjson/istreamwrapper.h"
   #include "rapidjson/stringbuffer.h"
   #include "rapidjson/ostreamwrapper.h"
   #include "rapidjson/filereadstream.h"
   
   #include "subprocess.hpp" /* MANDATORY: Allows to run Shunya AI binaries */
   #include "exutils.h" /* MANDATORY: Allows to parse Shunya AI binaries output */
   
   /* --- Shunya Interfaces Includes --- */
   #include <si/shunyaInterfaces.h> /* MANDATORY: Contains all IoT Functions */
   
   using namespace std;
   using namespace rapidjson;
   
   int main(void)
   {
       /* MANDATORY: Initializes the Shunya components */
       initLib();
   
       /* Write your code here */
   
   }      

3. Write code to read the value from the sensor.

   Voltage

   For reading data from Voltage sensor, write code

   int16_t voltage = getAdc(ADC_CHANNEL); /* ADC_CHANNEL is channel number i.e 0, 1, 2 ... */
   /* Replace ADC_CHANNEL with your connected channel */
   if (voltage < 0) {
       printf("Error unable to read Voltage. Error number %d= ", errNum);
   }

   Light Intensity

   For reading data from Light Intensity sensor, write code

   int16_t lightIntensity = getLux();
   if (lightIntensity < 0) {
       printf("Error unable to read lightIntensity. Error number %d= ", errNum);
   }

   Distance

   For reading data from Distance sensor, write code

   int16_t distance = getCm();
   if (distance < 0) {
       printf("Error unable to read distance. Error number %d= ", errNum);
   }

   Heart Rate

   For reading data from Heart Rate sensor, write code

   int16_t heartRate = getBpm();
   if (heartRate < 0) {
       printf("Error unable to read heartRate. Error number %d= ", errNum);
   }

   Liquid Flow

   For reading data from Liquid Flow sensor, write code

   int16_t waterflow = getLph();
   if (waterflow < 0) {
       printf("Error unable to read waterflow. Error number %d= ", errNum);
   }

4. Once you are done editing, save and compile the code , by running

   mkdir build && cd build
   cmake ../
   make 

5. Run the code

   sudo ./project-name

Facing errors with the component?