Generic IoT backend with a smart contract

IoT vendor smart contract interface

# check if device is present i.e. has ever pushed any data
function is_device_present (address device_id) public constant returns (bool result);
# get total device count
function get_device_count() public constant returns (uint count);
# enumerate device id's
function get_device_at_index (uint index) public constant returns (address device_address);
# get timestamp values containing data (for a specific device)
function get_device_timestamps (address device_id) public constant returns (uint[] timestamp);
# get stored file hashes (handles) with certain timestamp (for a specific device)
function get_device_data (address device_id, uint timestamp) public constant returns (string hash);
# push file hashes (handles) into the chain
function set_device_data (address device_id, string filehash) public returns (uint index, uint timestamp);
# event to log action
event log_action (address indexed device_id, uint index, uint timestamp, string filehash);

Deploying vendor smart contract

Deploy vendor smart contract (and event listener) to Ethereum network

> personal.unlockAccount(eth.coinbase);
Unlock account 0x55ac737cc9bc16ffd1af42e53ee1515e56b6a188
Passphrase: 
true
> 
> loadScript('vendor.js');
INFO [09-15|22:30:39] Submitted contract creation              fullhash=0xe1cac4360ae2e03708d5b56857432a8352ba362a62aca1e8b643da6a2a38837e contract=0x353ef87ff272733c0acd23540d2b2c8e4a9c0d63
null [object Object]
true
> 
INFO [09-15|22:31:09] Imported new chain segment               blocks=1 txs=1 mgas=1.312 elapsed=6.243ms  mgasps=210.146 number=88029 hash=4e28ea…092106
null [object Object]
Contract mined! address: 0x353ef87ff272733c0acd23540d2b2c8e4a9c0d63 transactionHash: 0xe1cac4360ae2e03708d5b56857432a8352ba362a62aca1e8b643da6a2a38837e
>
> loadScript('event.js');
true

Check if any IoT device is registered or ever pushed data

> browser_vendor_sol_vendor.get_device_count();
0

Sending IoT data to Swarm

Start sending data to Swarm filesystem and get file hashes (handles). In this IoT backend scenario Swarm system will be used as file storage and Ethereum blockchain as a file explorer

$ curl -H "Content-Type: text/plain" --data-binary '{ "timestamp": "1505477559", "payload": "hello from IoT device!" }' http://localhost:8500/bzz:/
44309aed2f2be69a23fa4747a950c266a79d0444efe7f74d8f358646f6ad8894
$ curl -H "Content-Type: text/plain" --data-binary '{ "timestamp": "1505477600", "payload": "lets throw another IoT device in the mix" }' http://localhost:8500/bzz:/
07db3c1a5ec6bb5eebc7f0f85bc7061db15305f8845a19b59286c9b4cc225551
$ curl -H "Content-Type: text/plain" --data-binary '{ "timestamp": "1505477700", "payload": "IoT device talking still" }' http://localhost:8500/bzz:/
9beba93cfa7c97d64b81c9a459e59c457794385006c2a71a1b41a6c3a64875f8
$ curl -H "Content-Type: text/plain" --data-binary '{ "timestamp": "1505477750", "payload": "IoT device end of talk!" }' http://localhost:8500/bzz:/
0e1b17b6c63d2b49e715d3ea8858506d2e079ac97d18663c7ca35b0b5512ace9
$ curl -H "Content-Type: text/plain" --data-binary '{ "timestamp": "1505477820", "payload": "bye from other IoT device" }' http://localhost:8500/bzz:/
a56c2b63d830363c18dbaae7388387511d96e3e129f6693a280ef7efb6265a51 

Tracking data via Ethereum blockchain

Send Swarm file hashes (handles) of uploaded files to Ethereum via smart contract

> browser_vendor_sol_vendor.set_device_data(eth.coinbase, '44309aed2f2be69a23fa4747a950c266a79d0444efe7f74d8f358646f6ad8894', {from: eth.coinbase, gas: 500000});
INFO [09-15|22:31:39] Submitted transaction                    fullhash=0x7f17070b6c129af55bc1f6f2e5db01a7a74bc143f09b41dc349ff9e5ab485cfb recipient=0x353ef87ff272733c0acd23540d2b2c8e4a9c0d63
"0x7f17070b6c129af55bc1f6f2e5db01a7a74bc143f09b41dc349ff9e5ab485cfb"
> 
> browser_vendor_sol_vendor.set_device_data('0xffecc801c6eed3fbc45d69e3e12ad4d9660f0d30', '07db3c1a5ec6bb5eebc7f0f85bc7061db15305f8845a19b59286c9b4cc225551', {from: eth.coinbase, gas: 500000});
INFO [09-15|22:32:00] Submitted transaction                    fullhash=0xce55e21ebd613fc64571e34cfe76cf026e2d99d1ead9246daacc11b7ac932bae recipient=0x353ef87ff272733c0acd23540d2b2c8e4a9c0d63
"0xce55e21ebd613fc64571e34cfe76cf026e2d99d1ead9246daacc11b7ac932bae"
> 
INFO [09-15|22:32:05] Imported new chain segment               blocks=1 txs=1 mgas=0.180 elapsed=6.345ms  mgasps=28.302  number=88035 hash=fba085…e51ca3
DEV[0x55ac737cc9bc16ffd1af42e53ee1515e56b6a188] INDEX[0] TIME[1505503913] HASH[44309aed2f2be69a23fa4747a950c266a79d0444efe7f74d8f358646f6ad8894]
INFO [09-15|22:32:36] Imported new chain segment               blocks=1 txs=1 mgas=0.180 elapsed=6.616ms  mgasps=27.270  number=88037 hash=28aeb0…f0a9a2
DEV[0xffecc801c6eed3fbc45d69e3e12ad4d9660f0d30] INDEX[1] TIME[1505503925] HASH[07db3c1a5ec6bb5eebc7f0f85bc7061db15305f8845a19b59286c9b4cc225551]

Force two transactions to push multiple file hashes into a single block (same block.timestamp or now)

> browser_vendor_sol_vendor.set_device_data(eth.coinbase, '9beba93cfa7c97d64b81c9a459e59c457794385006c2a71a1b41a6c3a64875f8', {from: eth.coinbase, gas: 500000});
INFO [09-15|22:32:43] Submitted transaction                    fullhash=0x1dc54a9fa237691943f5d1c457fbfc6886be0032c7ba54cb2777d9e4c849eff8 recipient=0x353ef87ff272733c0acd23540d2b2c8e4a9c0d63
"0x1dc54a9fa237691943f5d1c457fbfc6886be0032c7ba54cb2777d9e4c849eff8"
> browser_vendor_sol_vendor.set_device_data(eth.coinbase, '0e1b17b6c63d2b49e715d3ea8858506d2e079ac97d18663c7ca35b0b5512ace9', {from: eth.coinbase, gas: 500000});
INFO [09-15|22:32:44] Submitted transaction                    fullhash=0xd361ce246a3d956030898f1bd1e51d94ab62c4a59deabd27470a53d7eca41a64 recipient=0x353ef87ff272733c0acd23540d2b2c8e4a9c0d63
"0xd361ce246a3d956030898f1bd1e51d94ab62c4a59deabd27470a53d7eca41a64"
> 
INFO [09-15|22:33:21] Imported new chain segment               blocks=1 txs=2 mgas=0.264 elapsed=10.692ms mgasps=24.651  number=88041 hash=d8242d…2b8e78
DEV[0x55ac737cc9bc16ffd1af42e53ee1515e56b6a188] INDEX[0] TIME[1505503986] HASH[9beba93cfa7c97d64b81c9a459e59c457794385006c2a71a1b41a6c3a64875f8]
DEV[0x55ac737cc9bc16ffd1af42e53ee1515e56b6a188] INDEX[0] TIME[1505503986] HASH[0e1b17b6c63d2b49e715d3ea8858506d2e079ac97d18663c7ca35b0b5512ace9]

Send another file handle

> browser_vendor_sol_vendor.set_device_data('0xffecc801c6eed3fbc45d69e3e12ad4d9660f0d30', 'a56c2b63d830363c18dbaae7388387511d96e3e129f6693a280ef7efb6265a51', {from: eth.coinbase, gas: 500000});
INFO [09-15|22:33:26] Submitted transaction                    fullhash=0xcbdb05266990420962b7eec5ad327f759380396cfee6f5d163e4c70cd7e22c99 recipient=0x353ef87ff272733c0acd23540d2b2c8e4a9c0d63
"0xcbdb05266990420962b7eec5ad327f759380396cfee6f5d163e4c70cd7e22c99"
> 
INFO [09-15|22:33:56] Imported new chain segment               blocks=1 txs=1 mgas=0.121 elapsed=5.731ms  mgasps=21.069  number=88044 hash=ea2e8d…8f30bf
DEV[0xffecc801c6eed3fbc45d69e3e12ad4d9660f0d30] INDEX[1] TIME[1505504010] HASH[a56c2b63d830363c18dbaae7388387511d96e3e129f6693a280ef7efb6265a51]

Check how many devices are registered

> browser_vendor_sol_vendor.get_device_count();
2

Querying IoT backend and reaching stored data via Ethereum

Check timestamps and contents of received data (first device)

> browser_vendor_sol_vendor.get_device_timestamps(eth.coinbase);
[1505503913, 1505503986]
> 
> browser_vendor_sol_vendor.get_device_data(eth.coinbase, 1505503913);
"44309aed2f2be69a23fa4747a950c266a79d0444efe7f74d8f358646f6ad8894"
> 
> browser_vendor_sol_vendor.get_device_data(eth.coinbase, 1505503986);
"9beba93cfa7c97d64b81c9a459e59c457794385006c2a71a1b41a6c3a64875f8,0e1b17b6c63d2b49e715d3ea8858506d2e079ac97d18663c7ca35b0b5512ace9"

Check timestamps and contents of received data (second device)

> browser_vendor_sol_vendor.get_device_timestamps('0xffecc801c6eed3fbc45d69e3e12ad4d9660f0d30');
[1505503925, 1505504010]
> 
> browser_vendor_sol_vendor.get_device_data('0xffecc801c6eed3fbc45d69e3e12ad4d9660f0d30',1505503925);
"07db3c1a5ec6bb5eebc7f0f85bc7061db15305f8845a19b59286c9b4cc225551"
> 
> browser_vendor_sol_vendor.get_device_data('0xffecc801c6eed3fbc45d69e3e12ad4d9660f0d30',1505504010);
"a56c2b63d830363c18dbaae7388387511d96e3e129f6693a280ef7efb6265a51"

Look into Swarm handles received via Ethereum blockchain

$ curl -s http://localhost:8500/bzz:/44309aed2f2be69a23fa4747a950c266a79d0444efe7f74d8f358646f6ad8894
{ "timestamp": "1505477559", "payload": "hello from IoT device!" }
$ curl -s http://localhost:8500/bzz:/9beba93cfa7c97d64b81c9a459e59c457794385006c2a71a1b41a6c3a64875f8
{ "timestamp": "1505477700", "payload": "IoT device talking still" }
$ curl -s http://localhost:8500/bzz:/0e1b17b6c63d2b49e715d3ea8858506d2e079ac97d18663c7ca35b0b5512ace9
{ "timestamp": "1505477750", "payload": "IoT device end of talk!" }
$ curl -s http://localhost:8500/bzz:/07db3c1a5ec6bb5eebc7f0f85bc7061db15305f8845a19b59286c9b4cc225551
{ "timestamp": "1505477600", "payload": "lets throw another IoT device in the mix" }
$ curl -s http://localhost:8500/bzz:/a56c2b63d830363c18dbaae7388387511d96e3e129f6693a280ef7efb6265a51
{ "timestamp": "1505477600", "payload": "bye from other IoT device" }