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Device communication protocol

Each Solo device Receives and Transmits data. Here's how the communication flow is organized from a Solo device standpoint.

Basic concepts:

1. Each Solo device connected into a Chorus has its ID (order number), which is assigned dynamically upon initialization of the Chorus device from a communicating application. Normally enumeration starts with 0.
2. Each data chunk is a plain string terminated with "\n" character (ASCII=10) and having a predefined structure.
3. There are 3 types of data chunks:

• Requests
• Responses
• Pass-through data

4. Almost each Request produces a Response
5. Pass-through data is either a request to a different Solo device, or response which needs to pass through current device to reach the Bluetooth dongle and be transmitted to App.

Requests

There are 3 types of requests:

1. Device enumeration: (3 characters) "N" + <first_ID> + "\n". Example: "N0\n"
2. Command/Request: (4 characters) "R" + <device_ID> + <command> + "\n". Example: "R1T\n"
3. Calibration: (11 characters) "C" + <device_ID> + <time_long_HEX_value> + "\n". Example: "C00000010A\n"

In any "R" request: <device_ID> may be set to "*", which means the request is addressed to all devices (broadcast), and each should provide a response. Example: "R*A\n"

Note: for broadcast requests the order of responses from different devices is not defined. Example: "S1R1\nS0R1\nS2R1\n"

Responses

Response structure: "S" + <device_ID> + <response_type> + <data> + "\n" Each response type has its own predefined length depending on size of data to be transmitted.

Correspondence of Requests to Responses:

Description	Request	Response	Description	Example
Enumerate Devices	N	N	Number of Devices	N0\n -> N3\n (3 devices found)
Start Race	R	R	Race Status (1 = On, 0 = Off)	R*R\n -> S0R1\nS1R1\n...
End Race	r	R	Race Status (1 = On, 0 = Off)	R*r\n -> S0R0\nS1R0\n...
Increase Min Lap Time	M	M	Minimal Lap Time (1 byte, in seconds)	R*M\n -> S0M0A\n...
Decrease Min Lap Time	m	M	Minimal Lap Time (1 byte, in seconds)	R*m\n -> S0M0A\n...
Next Channel	C	C	Current Channel (1 byte)	R*C\n -> S0C05\n...
Previous Channel	c	C	Current Channel (1 byte)	R*c\n -> S0C04\n...