PHPoC - Monitor temperature and humidity via Samsung IoT Cloud

[Homer]

As you can see in other blogs, PHPoC devices can provide real-time monitoring via web or email. I just want to introduce another feature of PHPoC: monitoring via IoT cloud.

Samsung ARTIK Cloud is an open data exchange platform for the Internet of Things, which allows us to collect, store, visualize and analyze data from any device. For more information, you can visit https://artik.cloud.

This is a simple project that shows how to read temperature and humidity data from sensor, then send data to ARTIK cloud, by using PHPoC Blue. It's one more step to set up your own IoT system: monitoring temperature and humidity in your home via cloud server.

Demo

Hardware components:
PHPoC Blue × 1
Grove Temperature and Humidity Sensor (HDC1000) × 1
PHPoC Grove Expansion Board × 1

Wiring
- Stack Grove expansion board to PHPoC Blue
- Connect Grove Temperature and Humidity sensor (HDC1000) via I2C connector.




Setup ARTIK Cloud

First step is to create a new device type.
- Sign in to Developer Dashboard https://developer.artik.cloud/
- Select the tab Devices Types https://developer.artik.cloud/dashboard/devicetypes
- Click the "+ New Device Type"
- Set the device display name "HDC1000" and give it a unique name, for example, "com.phpoc.hdc1000"
- Click "Create Device Type" to create the device type

Create a new Manifest for the new device type
- Click "HDC1000" ==> "Set Up" ==> "Manifest" and then "New Manifest"
- Add two new data field, "temp" and "humid", with data type is Double, as below.



- Then "Next: Device Actions", and leave Actions as default
- Click "Activate Manifest" to finish creating new device type.



Go to MY ARTIK Cloud to create a new "HDC1000" device.

- Sign in to MY ARTIK Cloud https://www.artik.cloud/



- Choose Devices ==> select the "HDC1000" device type to add a new "HDC1000" device.



- Click "Add device", then set the name for this device (e.g. Temp and Humid Sensor)
- Select the newly created device. In the pop-up, click "GENERATE DEVICE TOKEN…".



After that, copy the Device ID and Device token. Set those values in your code (task0.php). Now the ARTIK setting up part is done.

$cur_device_id = "YOUR_DEVICE_ID";
$cur_device_token = "YOUR_DEVICE_TOKEN";

Sending data and monitoring on ARTIK Cloud

After the connection with ARTIK cloud has been set up, you can start sending data and visualize it on ARTIK.

- PHPoC will continuously read data from Temperature and Humidity Sensors, then it will send the message to ARTIK cloud using Web REST protocol.
- On MY ARTIK Cloud page, select Charts https://my.artik.cloud/data. From this window, you can monitor the visualized data.



Source code


hdc1000.php: Library for Temperature and Humidity Sensor HDC1000

<?php

if(_SERVER("REQUEST_METHOD"))
   exit; // avoid php execution via http request

include_once "/lib/sd_340.php";

define ("I2C_ID",   0);
define ("HDC1000_ADDR",      0x40);

define ("HDC1000_TEMP",      0x00);
define ("HDC1000_HUMID",      0x01);
define ("HDC1000_CONFIG",      0x02);

define ("HDC1000_SERID_1",      0xFB);
define ("HDC1000_SERID_2",      0xFC);
define ("HDC1000_SERID_3",      0xFD);
define ("HDC1000_MFID",         0xFE);
define ("HDC1000_DEVID",      0xFF);

define ("HDC1000_RST",         0x80);
define ("HDC1000_HEAT_ON",   0x20);
define ("HDC1000_HEAT_OFF",   0x00);
define ("HDC1000_BOTH_TEMP_HUMID",   0x10);
define ("HDC1000_SINGLE_MEASUR",      0x00);
define ("HDC1000_TEMP_HUMID_14BIT",   0x00);
define ("HDC1000_TEMP_11BIT",      0x40);
define ("HDC1000_HUMID_11BIT",   0x01);
define ("HDC1000_HUMID_8BIT",      0x02);

function set_register($reg)
{
   i2c_write(I2C_ID,($reg&0xff),1);
   usleep(20000);
}

function read_16bit()
{
   $data = 0;
   $LSB = 0x00;
   $MSB = 0x00;
   i2c_read(I2C_ID, $data, 2);
   $LSB = ($data>>8)&0xFF;
   $MSB = $data&0xFF;

   return (($MSB<<8)|$LSB);  
}

function read_config()
{
   set_register(HDC1000_CONFIG);
   return read_16bit();
}


function get_rawtemp()
{
   set_register(HDC1000_TEMP);
   return read_16bit();
}

function get_rawhumid()
{
   set_register(HDC1000_HUMID);
   return read_16bit();
}

function get_temp()
{
   $temp = (float)get_rawtemp();
   return ($temp/65536.0*165.0-40.0);
}

function get_humid()
{
   $humid = (float)get_rawhumid();
   return ($humid/65536.0*100.0);
}

function hdc_1000_init()
{
   i2c_setup(I2C_ID, HDC1000_ADDR, "sm");
}


?>

task0.php: Main program. Read temperature and humidity data from sensor, and then send to ARTIK cloud

<?php

if(_SERVER("REQUEST_METHOD"))
    exit; // avoid php execution via http request

include_once "/lib/sd_340.php";
include_once "/lib/sn_http_b1.php";
include_once "hdc_1000.php";

$cur_device_id = "YOUR_DEVICE_ID";
$cur_device_token = "YOUR_DEVICE_TOKEN";


function artik_post_msg($post_body, $device_token)
{
   $post_len = strlen($post_body);
   http_req_header("Content-Type: application/json");
   http_req_header("Authorization: Bearer $device_token");
   http_req_header("Content-Length: $post_len");
   $resp_head = http_request("POST", "https://api.artik.cloud/v1.1/messages", $post_body);

   if(!$resp_head)
   {
      echo "artik connection failed\r\n";
      return 0;
   }
   $http_status = (int)http_find_header($resp_head, "Status-Code");
   if($http_status != 200)
      echo "artik unexpected status $http_status\r\n";
   $resp_body = "";
   http_read_sync($resp_body);
   http_close();
   return $resp_body;
}


function gen_hdc_1000_msg($device_id, $temperature, $humidity)
{  
   $msg ="{ "sdid": "$device_id", "type": "message",\n "data": {"temp":$temperature, "humid":$humidity}}";
   return $msg;
}


hdc_1000_init();
while(1)
{
   $temp = get_temp();  
   $humid = get_humid();
   echo "Current temperature: $temp°C; humidity: $humid%\r\n";  

   $rest_body = gen_hdc_1000_msg($cur_device_id, $temp, $humid);  
   artik_post_msg($rest_body, $cur_device_token);  
   usleep(200000);
}

?>