Atlas Scientific makes an amazing suite of scientific grade environmental monitoring sensors that have a perfect synergy with the Plotly data visualization platform.
This Instructable will show you how to hook up an Atlas Dissolved Oxygen sensor and a Raspberry Pi to Plotly's real-time graphing platform. You will view your data in real-time in your web-browser! Here is our final product: A graph of our dissolved oxygen sensor in our Montr al office: http://plot.ly/~streaming-demos/52/!
You can also use Atlas's pH, ORP, and EC sensors simply by swapping out the appropriate circuit and probe. Calibration functions will vary for each sensor. This will work with the Arduino Yun, Beaglebone Black, or any other embedded linux platform.
Step 1: Hardware You Will Need
Step 2: Setup Raspberry Pi
Open the /etc/inittab file:
Add a '#' at the beginning of the following line so that it looks like this:#T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt10
sudo apt-get install python-serial sudo apt-get install git-core sudo apt-get install python-pip sudo pip install rpi.gpio sudo pip install plotly
Run the following commands in your Pi's terminal:
Reboot the Pi:
Step 3: Sign Up With Plotly
Step 4: Clone the Atlas-Scientific Repository
Clone the Repository from Github:git clone https://github.com/plotly/atlas-scientific.git
Open the Directory:
Or just copy the code from the files here: https://github.com/plotly/atlas-scientific
Step 5: Add Username, API Key, and Streaming Token
Open atlas-pi.pyvi atlas-pi.py
Fill in your Username, API Key, and Streaming Token.
Here is an example of what it should look like in the file:token = '5jpi07w226' username = 'arkeon' api_key = 'u6jlwbypiq'
Step 6: Wire It Up
Note: You could connect the Atlas circuit directly to the Raspberry Pi GPIOs using male-to-female jumper wires. Using the Pi Cobbler is good if you want to easily prototype with other sensors/devices.
Step 7: Calibrate the Sensor
Calibration should be done the first time the circuit is used. Dip your probe in water, just to get it wet. Let it sit in the air for 5 minutes. Do not leave it in water, it must calibrate to the oxygen level in the surrounding atmosphere. After 5 minutes, run the DOcalibrate.py file located in the /Calibrate/Pi folder in the atlas-scientific repository.sudo python DOcalibrate.py
You should see "Your Dissolved Oxygen Sensor is now Calibrated." in your terminal.
Step 8: See It In Action
You're ready to go now!
Run the atlas-pi.py file with this command:sudo python atlas-pi.py
If all goes well you should see the values spitting out in your terminal!
Step 9: Check the Plot
Now go to your Plotly account and you should see a graph called "Atlas Real-Time dOxy". Open the graph and see those beautiful values live streaming!!
Note that the plot above has had the Traces, Layout, and Axes all styled. Try out some customization of your own once you've created your plot. Have fun with it!
Step 10: Experiment!
The dissolved oxygen sensor is great for hydroponics, aquaculture, or any type of aerobic ferment, like a compost tea brewer. Wastewater treatment is another one. And if you decide to experiment with Atlas' other sensors, the sky is the limit. Do an experiment, stream your data, learn something awesome, and share what you find!