Enviro-Pi

LAMP and BLE-based environmental monitoring system for the Raspberry Pi and Arduino.

Supplies Needed

1. Computer w/ USB cable to run Arduino IDE
2. Central device: Raspberry Pi Zero W or Raspberry Pi B or Raspberry Pi B+ w/ optional screen and/or external wifi antenna
3. For each desired sensor: 1) Adafruit Feather 32u4 Bluefruit (with pre-soldered pins if desired) 2) Adafruit Si7021 sensor 3) LiPo or AA or AAA battery pack with JST connector and 4) jumper cables, solder, and header pins to connect sensor

Arduino Device(s) Setup

Setup Arduino IDE per the Adafruit instructions at https://learn.adafruit.com/adafruit-feather-32u4-bluefruit-le/setup

Follow the assembly steps for the Adafruit Si7021 sensor, detailed at https://learn.adafruit.com/adafruit-si7021-temperature-plus-humidity-sensor

Connect the Feather to the Si7021:

Feather	Si7021
3V	3V
GND	GND
SDA	SDA
SCL	SCL
-	VIN

Within the Arduino IDE, install the libraries: SparkFun_Si7021_Breakout_Library.h (instructions at https://github.com/sparkfun/SparkFun_Si701_Breakout_Arduino_Library) and LowPower.h ((https://github.com/rocketscream/Low-Power)

Open the Arduino file at https://github.com/prattpi/Enviro-Pi/tree/master/Arduino/environ_monitor_si7021_lp connect your device to the computer's USB cable, and select the appropriate board and port from the IDE Tools dropdown. Compile and then upload the code to the Arduino. The serial monitor will output the device's setup actions for debugging if needed.

Repeat the setup instructions for any additional Arduino sensors desired. You will also need the hw addresses of each sensor to set up the Pi configuration in the next step. A quick way to gather the addresses is to let the Pi scan for them using the hcitool command, e.g.:

pi@raspberrypi_ble:~ $ sudo hcitool lescan
LE Scan ...
F8:04:2E:87:52:2F (unknown)
46:0E:A3:3D:5A:6A (unknown)
46:0E:A3:3D:5A:6A (unknown)
C8:69:CD:50:7A:0F (unknown)
E4:6B:FA:9C:C0:A6 Bluefruit ES
E6:BF:8E:87:53:19 (unknown)

Here you can see one of the sensor devices at the address E4:6B:FA:9C:C0:A6. Note these addresses for the next steps.

Raspberry Pi Installation

Download and install to SD card the latest full version of Raspbian from https://www.raspberrypi.org/downloads/raspbian/

Create an empty file named SSH and add your wireless credentials to a wpa_supplicant.conf file containing the following:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
ssid="*your ssid*"
psk="*your password*"
key_mgmt=WPA-PSK
}

Copy both files into the /boot directory of the SD card.

Put SD card in Pi and plug in power to boot up. The Pi should automatically connect to your wireless network.

Log in to the Pi over SSH using the pi user and enter the default password raspberry.

First, run an update and upgrade:

sudo apt-get update && sudo apt-get -y upgrade  

Next, run:

sudo raspi-config 

And 1) choose "Change User Password", following the prompts to add your new password and then 2) set the Pi to boot to command line (choose "#3 Boot Options" -> B1 Desktop/CLI -> B1 Console) and 3) Choose localization options to select your timezone, and then save and reboot as prompted.

Now download and unzip the files into a new enviropi directory:

cd ~pi && wget https://github.com/prattpi/Enviro-Pi/archive/master.zip && unzip master.zip -d /home/pi/ && mv /home/pi/Enviro-Pi-master /home/pi/enviropi && cd enviropi

Then run the installation file (you will need your sensors' hw addresses or you can manually edit the ini file later):

chmod +x install.sh
./install.sh 

The final output of the install script will give you the URL to the dashboard interface, i.e. http://yourpiipaddress Once data has had time to accumulate the dashboard will look something like this:

Additional Notes

Data storage

Each Arduino sensor generates about 28.8 KB of data on in the Pi's disk per day. At that rate, a small-ish SD Card capacity such as 16GB is plenty, even with multiple sensors.

Adafruit.io dashboard

Adafruit.io offers an IoT data service (currently in beta) that can easily be integrated into the pygatt script. More info at https://learn.adafruit.com/welcome-to-adafruit-io

source /home/pi/enviropi/env/bin/activate pip install adafruit-io

Optionally may add external antenna and/or screen

For screen, such as the Waveshare 3.5inch RPi LCD (B), need to install the GUI (if installed Raspbian Lite version):

sudo apt install raspberrypi-ui-mods

Then follow instructions here: https://www.waveshare.com/wiki/3.5inch_RPi_LCD_(B)#Method_1._Driver_installation

For wifi adapter for better range, to get it to use that as wlan0 you need to disable the built-in wifi by doing the following:

sudo nano /etc/modprobe.d/brcmfmac.conf

And add the single line to the file:

blacklist brcmfmac

Reboot and the Pi will come up again with the external wifi adapter as wlan0.

For screen GUI:

source /home/pi/enviropi/env/bin/activate sudo apt-get install python3-tk

Screen file is:

/home/pi/enviropi/screen.py

With .desktop file to run it:

(env) pi@raspberrypi_ble:~/enviropi $ more ../Desktop/GUI.desktop

[Desktop Entry]
Name=EnviroPi Control
Icon=/usr/share/pixmaps/debian-logo.png
Terminal=true
Type=Application
Exec=/home/pi/enviropi/env/bin/python /home/pi/enviropi/screen.py

To start at boot time:

nano .config/lxsession/LXDE-pi/autostart

@/home/pi/enviropi/env/bin/python /home/pi/enviropi/screen.py