SensorTag to Blynk Using Node-RED

How to merge different IoT devices and services? Node-RED provides an elegant solution.

Node-RED provides an elegant solution to merge different IoT devices and services.

• The SensorTag acquires weather data and sends them to the Raspberry Pi through BLE (Bluetooth Low Energy).
• The Node-RED flow runs on the Raspberry Pi, processes the weather data and sends to the Blynk server, either on the cloud or locally, through WiFi.
• An iOS- or Android-based phone or tablet connects to the same Blynk server, either on the cloud or locally, and displays the measures on a beautiful way.

The RedBear IoT pHAT provides BLE and WiFi to the Raspberry Pi Zero.

General Preparation

Download the Debian Jessie Lite image and prepare a microSD-card. On macOS, I’m using ApplePi-Baker to prepare the microSD-card.

In order to enjoy SSH through USB, update the microSD-card on the main computer with

$ 
nano config.txt 

At the very bottom, add

dtoverlay=dwc2 

Press ctrl-O ctrl-X to save and close. Then launch

$ 
nano cmdline.txt 

After rootwait, add a space then

modules-load=dwc2,g_ether 

Press ctrl-O ctrl-X to save and close. Power-cycle the Raspberry Pi.

Connect to the Raspberry Pi, with an USB cable on USB port. On the main computer,

$ 
ssh [email protected] 

Default password is raspberry.

To proceed with the update and upgrade, launch on the Raspberry Pi

$ 
sudo apt-get update 
sudo apt-get upgrade 

Set the timezone. Launch on the Raspberry Pi

$ 
sudo raspi-config 

Install and run rpi-update. Launch on the Raspberry Pi

$ 
sudo apt-get install rpi-update 
sudo rpi-update 

Install RedBear IoT pHAT

Power the Raspberry Pi off, plug the RedBear IoT pHAT on the Raspberry Pi, power the Raspberry Pi on, connect to it and launch

$  
cat /proc/device-tree/hat/product 

If the answer is IoT pHAT w/eep_v0.3, the board is ready. Proceed to next section. Otherwise, the EEPROM needs to be updated. Just follow this procedure.

To confiture WiFi, launch on the Raspberry Pi

$ 
ifconfig 
sudo nano /etc/wpa_supplicant/wpa_supplicant.conf 

Add at the end

network={ 
   ssid="SSID" 
   psk="passwork" 
   key_mgmt=WPA-PSK 
} 

Press ctrl-O ctrl-X to save and close. Finally, reboot.

$ 
sudo reboot 

Connect using Ethernet over USB or WiFi and launch on the main computer

$ 
ssh [email protected] 

Default password is raspberry.

To check Bluetooth is running, launch on the Raspberry Pi

$ 
hciconfig 
hci0:	Type: BR/EDR  Bus: UART 
	BD Address: E0:76:D0:CF:2F:A4  ACL MTU: 1021:8  SCO MTU: 64:1 
	UP RUNNING  
	RX bytes:717 acl:0 sco:0 events:42 errors:0 
	TX bytes:1532 acl:0 sco:0 commands:42 errors:0 

To scan Bluetooth devices, launch on the Raspberry Pi

$ 
bluetoothd -v 
5.23 
sudo bluetoothctl 
[bluetooth]# 
scan on 
[NEW] Device B0:B4:48:ED:B4:84 CC2650 SensorTag 
[bluetooth]#  
connect B0:B4:48:ED:B4:84 
Attempting to connect to B0:B4:48:ED:B4:84 
[CHG] Device B0:B4:48:ED:B4:84 Connected: yes 
Connection successful 
[bluetooth]#  
trust B0:B4:48:ED:B4:84 
[CHG] Device B0:B4:48:ED:B4:84 Trusted: yes 
[bluetooth]#  
quit 

The SensorTag Node-RED requires Bluetooth, as well as an Ethernet over USB connection or a WiFi connection.

Install node, npm and Node-RED

Launch on the Raspberry Pi

$ 
sudo apt-get update 
sudo apt-get install node 
sudo apt-get install nodered 
sudo apt-get install npm 

Check

$  
node -v 
v0.10.29 
npm -v 
1.4.21 

To obtain release 0.12 of node, launch on the Raspberry Pi

$ 
wget https://s3-eu-west-1.amazonaws.com/conoroneill.net/wp-content/uploads/2015/02/node-v0.12.0-linux-arm-pi.tar.gz  
tar -zxvf node-v0.12.0-linux-arm-pi.tar.gz 
cd node-v0.12.0-linux-arm-pi 
sudo cp -R * /usr/local/ 
cd .. 
sudo rm -R node-v0.12.0-linux-arm-pi 
node -v 
v0.12.0  

To install Node-RED

$ 
sudo apt-get install nodered 

To install npm to manage additional nodes,

$ 
sudo apt-get install npm 

To obtain release 2.15 of npm, launch on the Raspberry Pi

$ 
sudo npm install -g [email protected] 
npm -v 
2.15.11 

Install Additional Nodes

There are two releases for the SensorTag, node-red-contrib-sensortag and node-red-node-sensortag. I managed to get the first one to work.

$ 
sudo apt-get install libbluetooth-dev libudev-dev pi-bluetooth 
sudo setcap cap_net_raw+eip $(eval readlink -f `which node`) 
cd ~/.node-red 
npm install node-red-contrib-sensortag 

List the installed nodes

npm list 
└─┬ [email protected] 
 └─┬ [email protected] 
   └─┬ [email protected] 
     └─┬ [email protected] 
       ├── [email protected] 
       └─┬ [email protected] 
         └── [email protected] 

To install the Blynk node, launch on the Raspberry Pi Zero

$ 
hash -r 
cd ~/.node-red 
npm install node-red-contrib-blynk-websockets 

Launch the Blynk app

On the iOS- or Android-based phone or tablet, install the Blynk app and launch it. Enter your credentials, either to Blynk cloud or a local server.

Source: SensorTag to Blynk Using Node-RED