Pebble IoT Prototyping board is an interesting example of a Blockchain "Hardware Oracle": it's designed by IoTeX in partnership with Nordic Semiconductors and works in combination with the IoTeX Blockchain by providing a "trusted, verifiable view" of it's surrounding environment:

It provides:

- Temperature, Humidity, Barometric Pressure
- Air Quality (VOCs)
- GPS location
- 3-Axis accelerometer data
- 3-Axis gyroscope data
- Ambient light measurement

it signs and sends the signed data to either an MQTT server or to the blockchain directly, such that both the data and the data source can be verified by anyone through the signature.

As it's equipped with secure hardware onboard to securely generate and hold the private key, this represents a valid, innovative design for building "Trusted Oracles".

There is also an idea-thon going on! (you can win prizes up to 200$ or a Ucam (another blockchain-enabled product available on Amazon!)