RPi to BlockchainDB

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  VPN Fist Fight: Tunnelblick for Mac

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  VPN Fist Fight: OpenVPN for Raspberry Pi

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  BigChainDB node in a hashstaX workpace

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  Deploying the node with Docker on Mac OSX. What's a MESH Node Address? Oh, it's the second IPv4 address (the VPN one).

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  Posting and reading data with the swagger UI. Where do I get the passphrase? Oh, I can just type anything I want.

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  Time to add an Edge Device. RPi with SenseHAT: reads temp. press. humidity, orientation, acceleration.

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  Website hosted on Raspberry Pi with python/flask. Displays SenseHAT data.

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  REST in Javascript: Connecting the Lightbulb to the switch. Thank you stackoverflow!!

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  Look! Actual Code! Also see https://gitlab.com/LeoSalemann/iot110-leos/tree/master/Lab06

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  All that in seven commits (with a bunch more form earlier).

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  Try a GET via hashstaX/swag ...

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  IT WORKS! Data from a Raspberry Pi SeneHat, logged into a blockchain database, and hashstaX did all the hard stuff.

Inspiration

I started with a simple exploration of hashstax, figuring out what I could do with it. After a few fall starts, I homed in on a storage solution based on BigchainDB. Once I could post and read simple data with the Swagger REST GUI, I turned to my Raspberry Pi with its SenseHAT as s source of real data.

What it does

A Raspberry Pi with a SenseHat detects humidity, pressure, temperature, accelerometer and orientation data, streaming all of this to a BigchainDB node running as a couple docker containers on a MacBook pro. A bit of javascript on the Pi's web client makes the REST POST call to send the data to BigchainDB.

How I built it

The BigChainDB node was created and deployed with hashstax. I never had to deal with the blockchain directly. Using HashstaX's Swagger UI I tested the REST API functions for posting and getting data. Once I had that working, I turned to an a Raspberry Pi project from an IoT class I took through University of Washington Professional & Continuing Education. Which hosted a python web server on the Pi using Flask, pulling environmental data from a SenseHAT and presenting it to the client with a Boost/javascript/html/css front end. I ended up making an extra REST POST call in the javascript to send the sensor data to the BigchainDB node.

Challenges I ran into

1. Figuring out what VPN clients to use. Ended up with tunnelblick on MacBook; NordVPN on Raspberry Pi.

2. When it came time to deploy the BigChainDB node from hashstax, I was prompted to provide MESH Node address. Had no idea what it was; turned out to be the IPv4 address from the VPN.

3. Once I started testing on with SwaggerUI, I was asked for a passprhase. Which passphrase? Where do I get it from? Turns out I could type anything I want.

4. Figuring out how to translate a curl REST call into javascript was tricky, but that could be cured through routine googling and stackoverflow. The other problems needed in-person tech support. Thanks, T-Labs!

Accomplishments that I'm proud of

I had fully-intended to spend the entire weekend just learning and noodling around with technology. I had no product or business plan whatsover. It was very satisfying to pull together a full end-to-end solution that could be used to address many needs from many people.

What I learned

Good thing I had been exposed to Docker, REST API's, and basic web-dev (html/css/javascript/flask), or I would have been sunk. The main learnings from this project include hashstax, BigChainDB, and calling REST through javascripts.

What's next for Streaming data from RPI to BigChainDB with hashstax

I should really be doing the REST calls from the server side; probably through python. It would also be cool to deploy the hashstax containers to Azure, AWS, or Googcle Cloud Platform so they could run independent of my MacBook.

Built With

• blockchain
• hashtax
• html
• javascript
• python
• rest