What's in your blockchain powered IoT sensor?

Here's what's in mine :)

Made from off-the-shelf components (except for the firmware) and costing about $280 CAD. This price includes fully custom firmware written by yours truly - to which I give a value of $30 in the BOM - about the same cost as the LORA-E5-MINI board that hosts it. It takes me about a day to make one of these, and I've made 2 so far. You can see the data from this very unit pictured above here: https://www.measurement.earth/pages/data/index.html?station=a11111d.meas&chain=testnet

What makes this device so special? Most sensors are focused on sending raw measurements to a 'cloud server' where it goes into a private database somewhere (like AWS or Azure or Datacake, etc.). My sensor, however, sends its raw data to a public database - a blockchain. In particular, a blockchain called TELOS based on the EOS technology (from 2018 fame). To send data to a blockchain requires that the data is specially formatted and signed - yes digitally signed with the sensor's own private key - proving the sensor measurements came from this device and nowhere else - immutable and unmodifiable.

The really neat thing about all this is that it does everything including the blockchain transaction generation and signing on a 3x3 mm STM32 microcontroller - a veritable grain of silicon rice!

For now this has been mostly a cool thing I can put on my resume with little commercial value. Air quality is one thing, yes it's useful to know but around here (Calgary CA) the air is wonderful and people take it for granted and don't really care. Blockchain is another thing - people have heard of it - "bitcoin you say?" but that's it. So why blockchain? Can't say I can answer this clearly otherwise I'd be making a lot more than two. But there are some possibilities hanging around in the aether - small groups, some well funded, are exploring these ideas - like building data models on large scale environmental phenomena where data authenticity is important. Blockchain is perfect for these applications. Remember, my sensors produce data that is provably guaranteed to have come from the device it claims to have come from and no one can alter or dispute that. That's the power of blockchain!

As this project slowly evolves I want to get the costs down and especially the assembly time. Custom hardware is the answer to both, and for that, however, I will need a sponsor or interested party to help fund that. Did I mention this sensor also uses the LoRaWAN/Helium network to send the blockchain transaction data? It's 195 bytes and requires SF7, a little larger than what most people think about when considering LoRaWAN, but it works fine. Helium charges me $0.01 per 24 bytes, or about 8 cents per uplink. I send these every 15 minutes so the operational costs are quite low. The blockchain itself requires me only to stake a small amount of tokens (< 1 "TLOS") to enable the devices to transact freely without a fee-per-transaction model (like Ethereum). This is what drew me to EOS technology in the first place - along with the standardized security model (essentially the same as bitcoin) that could be trusted as well as implemented in firmware with standard libraries.

Until next time, thanks for reading.