vevor-heater-ble 0.1.3

A simple API for BLE-enabled Vevor independent heaters

vevor-heater-ble

Communication protocol

The BLE communication protocol for the heater is rather convoluted. Instead of requesting an authentication passkey, the heater expects the client to write the passkey to a predefined characteristic to authenticate itself. The heater then responds with a single notification providing the values. Any other attempts to retrieve the value of the characreristic will result in an empty response.

The service and the characteristic are identified by the following UUIDs respectively: 0000ffe0-0000-1000-8000-00805f9b34fb and 0000ffe1-0000-1000-8000-00805f9b34fb. The latter is also used to subscribe to the response notifications.

Request format

Offset	Value	Description
0	0xAA	Magic version constant
1	0x55	Magic version constant
2	0x0C	Two most significant decimal password digits (12)
3	0x22	Two least significant decimal password digits (34)
4	0x01-0x04	Command to run (see below for more details)
5	depends	Value to send alongside the command.
6	0x00	??? (padding, always zero)
7	any	Checksum, sum of values at offset 2-6 modulo 256

Request commands

Value	Accepted Data Values	Description
1	0	Ping, readonly device status request
2	1, 2	Operational mode. 1 - manual power level, 2 - automatic temperature-based control
3	0, 1	Turn the heater off / on
4	[1, 10] for op. mode 1, [8, 36] for op. mode 2	The desired temperature / power level

Response format

All values are unsigned, little endian encoded integers, unless specified otherwise.

Offset	Length	Values	Description
0	1	0xAA	Magic version constant
1	1	0x55	Magic version constant
2	1	0x01-0x04	Command this message is a response to (see above for details)
3	1	0x00, 0x01	Heater power status (on / off)
4	1	0x00-0x0A	Error code (range taken from printed manual)
5	1	0x00-0x04	Running state Warmup Self test running Ignition Heating Shutting down
6	2	any	Altitude
8	1	0x01, 0x02	Operational mode
9	1	[1, 10] for op. mode 1, [8, 36] for op. mode 2	Target temperature / power level
10	1	[0, 9], only for for op. mode 2	Current power level. Offset by one when compared to the power level operation mode.
11	2	any, typ. [90, 180]	Voltage of the power supply, in decivolts (0.1 V)
13	2	any	Temperature of the heating element, in degrees Celsius.
15	2	any	Temperature of the room, in degrees Celsius.
17	1	0x01-0x0A	Display error code (should correspond with the error code on the heater display)
18	1	0x00	??? (padding, always zero)
19	1	any	Checksum, sum of values at offsets [3;(last-1)] modulo 256