'Detecting authorized boarding is extremely important for us from a safety standpoint. It even works when there is no cellular or WiFi connectivity on the bus.

This improves the passenger experience and reduces the workload for bus conductors.

Passengers can easily show that they have a valid ticket by sending a chirp signal from their phone to the conductor, instead of having manually present a ticket. But with ‘chirping’ capability built into the home monitor it’s possible to have the customer simply hold their phone near the device and the support technician could query the status of the home monitor through chirp sound signals. What happens when the customer is trying to install it is having problems as it can’t connect to the WiFi network? It’s difficult for a remote technician to troubleshoot the device as they can’t check the status of the device. It isn’t designed for mission critical IoT applications with large data payloads such as industrial gear.Ĭonsumer applications Consider a home monitor that’s designed to connect through a home WiFi network. It’s ideal for small, dynamic payloads such as a network of sensors and gateways.The information to be transmitted is encoded and decoded in real-time, without any external resources that might require a network connection.The data to be transmitted is encoded by generating a new signal whose properties are determined by the data to be transmitted, and does not require an existing audio signal.Chirping handles these constraints, and also has other benefits: They have to communicate with other sensors and devices that are installed later without requiring reconfiguration. IoT sensors have to conserve power so they can work for extended periods without recharging. Devices don’t even need a prior ‘handshake process’ before they can exchange data.

It’s ideal for broadcasting data in a ‘one to many’ network configuration to devices as sound travels in all directions. Chirps maybe audible, or silent (ultrasound) to minimize noise pollution.Ĭhirping is peer-to-peer that doesn’t require connections to ‘the cloud’. The data is encoded into a series of pitches and tones on the sending device, and then decoded on the receiving device. Data is encoded through modulation/demodulation. BackgroundĪ chirp is a signal in which the frequency increases (up-chirp) or decreases (down-chirp) with time. The amount of data that can be transmitted with audio signals, however, is much less than with Bluetooth and WiFi. Audio signals can traverse over 500 feet using simple speakers and microphones that require very little power. Audio signals work at much lower frequencies around 20 to 20,000 Hz. Bluetooth operates at 2.4 GHz with a range of under 33 feet while WiFi works at 2.4 GHz and has a range of around 60 feet depending on obstructions.

Download chirp sdk for android