WBRL Peephole Camera Protocol

This topic describes the communication protocol and data exchange for audio and video transmission between the peephole camera and the WBRL module.

Hardware description

Hardware connection

The following figure shows the connection between the WBRL module and the peephole hardware.

Pin definitions

Type	Pin	Description
SPI pins	PA28	Chip select
	PA30	Clock signal from the main, used by the sub to send and receive data.
	PA25	Main out, sub in.
	PA26	Main in, sub out.
Special pins	PA12	The wake-up pin, normally low. To wake up the peephole, pull up this pin for 250 milliseconds and then pull down it. When the peephole detects that this pin is high for 250 ms, it will wake up. Note: The peephole should not wake up upon detecting a single rising edge, which may occur due to a brief high signal from io_wakeup after the WBRL module restarts.
	PB21	Data request. This pin is normally low. When the WBRL module is ready to receive data, it pulls this pin up and then down. The main sends data only when detecting a rising edge change on this pin.
	PB20	Clock request. This pin is normally low. To send data, the WBRL module pulls this pin up and then down. When detecting a rising edge change, the main generates a clock on which the WBRL module sends data.

SPI parameters

Clock rate	Clock mode	Data transfer	Chip select	Data width	Main-sub setting
Up to 25 MHz (8 MHz recommended).	MODE0: Mode 0 [CPOL=0,CPHA=0]	MSB	Active low	8 bits	The peephole is the main while the module is the sub.

Notes

If possible, you can reserve one or two I/Os for future feature expansion.

How it works

Interaction

Data length

The WBRL module and the peephole communicate using a fixed-length data format of 3,872 bytes. If the packet length is less than 3,872 bytes, pad it with zeros after the payload.

Wake up

1. To wake up the peephole, the WBRL module pulls up PA12 for 500 milliseconds and then pulls it down. When the peephole detects that this pin is high for 500 ms, it will wake up. The WBRL module can wake up the peephole up to three times.

2. The WBRL module is the sub, while the peephole is the main. Therefore, the peephole cannot determine if the WBRL module is ready to read or write data. To avoid timing issues during data exchange, send data or clock signals only after the level on PB21 or PB20 changes.

   The WBRL module cannot detect the peephole wake-up state, so when the peephole wakes up, it notifies the WBRL module by sending 0x63.

3. After the peephole sends the command 0x63, if the WBRL module fails to send the clock pin change within the timeout, the peephole will resend 0x63 each time the WBRL module pulls up PB21.

Upload image, video, or audio

1. The WBRL module responds to the command 0x63 by pulling up PB20 to request image or video upload and reports its readiness.
2. The peephole operates based on the response to 0x63.
   • Not ready: The peephole continuously sends the command 0x63 to check the readiness of the WBRL module until it is ready.
   • Ready: Streaming is ready.
   • Failed: The peephole stops transmission and queries and then enters sleep mode.
3. After the peephole receives a ready status from the WBRL module, it will send the command 0x61 the next time PB21 is pulled up to transmit image or video data to the WBRL module. During this period, each time the WBRL module pulls up PB21, the peephole sends a data packet but cannot send data proactively.
4. After the image or video upload is completed, the WBRL module pulls up PB20 and sends the command 0x6F to notify the peephole of completion. After receiving this notification, the peephole does not respond to the WBRL module and can enter sleep mode directly.

Send audio

1. The mobile app sends audio to the device for two-way talk.
2. After the WBRL module establishes a stream, it will pull up PB20 and send the command 0x68 to the peephole before transmitting audio. During this period, each time the WBRL module pulls up PB20, the peephole sends a clock signal.

QR code pairing

1. After waking up, the peephole sends the command 0x63 to the module.
2. The WBRL module requests QR code information for pairing from the peephole, which waits for changes in the I/O pin.
3. After the WBRL module retrieves PB21, the peephole sends the QR code information using the command 0x6A without waiting for a response from the module.
4. After the WBRL module receives the QR code information, it pulls up PB20 and notifies the peephole of process completion with the command 0x6F. After receiving this notification, the peephole does not respond to the WBRL module and can enter sleep mode directly.

Protocol list

(Optional) Query product information (0x01)

The peephole sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x01
Data length	2	N
Data	N	Product information, for example, {"p":"vHXEcqntLpkAlOsy"}.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The module returns the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x01
Data length	2	0001
Data	1	0x00: Success. 0x01: Failure.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Get the PID

Initiate transmission (0x63)

The peephole only supports images and videos.

The peephole sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x63
Data length	2	0x0006
Get time type	1	0x00: Local time 0x01: GMT
Video resolution (defaulting to 0 for images)	1	0x00: 320 × 240 0x01: 640 × 480 0x02: 1280 × 720 0x03: 1920 × 1080 0x04: 2304 × 1296
Video type (defaulting to 0 for images)	1	0x00: MPEG-4 (not supported currently) 0x01: H.263 (not supported currently) 0x02: H.264 0x03: MJPEG 0x04: H.265
Video frame rate (defaulting to 0 for images)	1	Set the actual frame rate of your peephole. 10 to 20 fps are supported.
Video bitrate (defaulting to 0 for images)	2	The following parameters are supported: 64: 64 kbit/s 128: 128 kbit/s 256: 256 kbit/s 512: 512 kbit/s 768: 768 kbit/s 1024: 1 Mbit/s 1536: 1.5 Mbit/s 2048: 2 Mbit/s
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The peephole supports images, videos, and audio.

The peephole sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x63
Data length	2	0x0010
Get time type	1	0x00: Local time 0x01: GMT
Video resolution (defaulting to 0 for images)	1	0x00: 320 × 240 0x01: 640 × 480 0x02: 1280 × 720 0x03: 1920 × 1080 0x04: 2304 × 1296
Video type (defaulting to 0 for images)	1	0x00: MPEG-4 (not supported currently) 0x01: H.263 (not supported currently) 0x02: H.264 0x03: MJPEG 0x04: H.265
Video frame rate (defaulting to 0 for images)	1	Set the actual frame rate of your peephole. 10 to 20 fps are supported.
Video bitrate (defaulting to 0 for images)	2	The following parameters are supported: 64: 64 kbit/s 128: 128 kbit/s 256: 256 kbit/s 512: 512 kbit/s 768: 768 kbit/s 1024: 1 Mbit/s 1536: 1.5 Mbit/s 2048: 2 Mbit/s
Audio type	1	0x65 (101): PCM (not supported currently) 0x6A (106): G711A
Audio frame rate	1	Set the actual frame rate of your peephole. 10 to 20 fps are supported.
Audio sampling rate	4	8000: 8 kbit/s 11000: 11 kbit/s 12000: 12 kbit/s 16000: 16 kbit/s 22000: 22 kbit/s 24000: 24 kbit/s 32000: 32 kbit/s 44000: 44 kbit/s 48000: 48 kbit/s
Audio bit depth	1	0x08: 8 bits 0x10: 16 bits
Audio channel	1	Default to 0 (not in use yet)
The angle of rotation.	1	0x00: 0 (default) 0x01: 0° 0x02: 90° 0x03: 180° 0x04: 270°
Weather schedule	1	Bit 7: 0: Disable. 1: Enable. Bits 0 to 3: The specified time period, in hours. Bits 4 to 6: Reserved.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The WBRL module returns the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x63
Data length	2	0x000e
Current status	1	0x00: Not ready. 0x01: Connecting to the network. 0x02: Ready. The peephole can transmit data via 0x61 after receiving this status. 0x03: Uploading data. 0x04: Operation failed. Stop transmission and query. 0x05: Data is too large. 0x06: Device testing mode.
Event type	1	0x01: Capture an image. 0x02: Enable live video. 0x03: Request QR code information. 0x04: Request PID information. 0x07: Request weather.
Maximum transmission unit	4	The maximum size of an image packet. If exceeded, the data will be fragmented for transmission.
Time data	8	The data length is eight bytes. Data[0] indicates whether the time is obtained successfully. 0: Failure. 1: Success. Data[1] indicates the year. 0x00 indicates the year 2000. Data[2] indicates the month, ranging from 1 to 12. Data[3] indicates the day, ranging from 1 to 31. Data[4] indicates the hour, ranging from 0 to 23. Data[5] indicates the minute, ranging from 0 to 59. Data[6] indicates the second, ranging from 0 to 59. Data[7] indicates the day of the week, ranging from 1 to 7, with Monday as 1. If the time is in GMT, the day of the week is invalid.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Upload audio and video (0x61)

The peephole sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x61
Data length	2	N + 5
Image sequence number	2	Default to 0. When transferring multiple images, the sequence number increments from 0 with each transfer and resets to zero after completion.
Fragmentation flag	1	0: Fragmentation not used. 1: Fragmentation starts. 2: Fragmentation content. 3: Fragmentation ends.
Fragmentation sequence number	1	The sequence number starts at 0 and increments sequentially.
Frame format	1	0x00: P-frames or B-frames. 0x01: I-frames or MJPEG. 0x03: Audio frames.
Data	N	Data
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Send audio (0x68)

The module sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x68
Data length	2	N + 9
Audio type	1	0x00: G.711 A-law 0x01: PCM (not supported currently)
Reserved fields	8	The field must be set to 0.
Data	N	Audio data
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Complete transmission (0x6F)

After the audio and video transmission is complete, the module will notify the peephole of entering sleep mode with the command 0x6F to conserve power.

The module sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x6F
Data length	2	0x0001
Status	1	0x00: Streaming ends and the peephole enters sleep mode.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The peephole returns the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x6F
Data length	0	0x0000
Data	None
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

QR code pairing (0x6A)

The peephole sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x6A
Data length	2	N
Data	N	{"p":"12345678","s":"ydc","t":"AZJ5zpswTfpr_0"}
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The module returns the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x6A
Data length	2	0x0001
Data	1	0x00: Success. 0x01: Failure. 0x02: Connected to the router.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Device testing (0x6E)

The module sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x6E
Data length	2	4 + N
Subcommand	1	0x00 (reserved)
Wi-Fi scanning results	1	0x00: Success. 0x01: Failure.
rssi	1	The signal strength percentage of the scanned router, ranging from 0 to 100.
Length of firmware version number	1	The byte size of the firmware version number.
Firmware version number	N	A variable-length string, such as 1.0.0.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The peephole returns the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x6E
Data length	2	0x0000
Data	0	None
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Testing process

1. The door lock PCB initiates a test with the command 0xF0.
2. After receiving 0xF0, the module performs a test, wakes up the peephole, and notifies it to enter testing mode with the command 0x63 via SPI.
3. Upon receiving 0x63, the peephole performs the specified test.
4. After the module completes testing, it notifies the peephole of the results via SPI using 0x6e, which then displays relevant information including the module’s firmware version and Wi-Fi signal strength. The module then enters deep sleep mode, enabling you to monitor the overall power consumption.

Get weather service (0x85)

1. The peephole requests weather information using the command 0x85.
2. Upon receiving the command, the module verifies the weather parameters and then sends the weather data to the peephole using the command 0x86.

The peephole sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x85
Data length	2	0x0005
Get weather type	4	See Appendix 2.
Number of forecast days	1	The number of forecast days, ranging from one to seven.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The module returns the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x85
Data length	2	0x0001
Data	1	0x00: The request parameters are correct. 0x01: The request parameters are incorrect.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Send weather data (0x86)

The module sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x86
Data length	2	N (KDTLD + KDTLD +…)
Data	N	Response in the KDTLD format.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Field description:

• K (4 bytes): The name of the request parameter. See Appendix 1.
• D (1 byte): The number of forecast days.
• T (1 byte): The parameter type.
• L (2 bytes): The length of one KDTLD.
• D: The payload.

Switch video mode (0x88)

Switch between camera views on the mobile app. See Appendix 5 for details.

The module sends the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x88
Data length	2	N
Data	N	Data[0]: 0x00 to 0xFF. 0x00: The default main frame. 0x01 to 0xFE: The frame ID. 0xFF: Query from the app panel.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

The peephole returns the following data.

Field	Length (byte)	Description
Header	2	0x55aa
Version	1	0x00
Command	1	0x88
Data length	2	N
Data	N	Data[0]: Status. 0x00: Success. 0x01: Failure. Data[1 to N-1]: The full data. Data 1, Data 2 … Data n on success or failure if the position label is included. See the following for the data format. Data is a fixed 2-byte value of 0xFFFF if no position label is included.
Checksum	1	Start from the header, add up all the bytes, and then divide the sum by 256 to get the remainder.

Field description:

When switching to another screen, users tap the target sub frame, which will be swapped with the current main frame. Consequently, the RN panel and miniapp send the ID of the sub frame to the device.

The full data supports N channels, defined as follows:

Main frame (1 + 1 byte)	Sub frame 1 (1 + 1 byte)	…	Sub frame n (1 + 1 byte)
ID + Location type	ID + Location type		ID + Location type

The code for location type is defined as follows:

• 0x01: Main
• 0x02: Sub
• 0x03: Front
• 0x04: Back
• 0x05: Up
• 0x06: Down
• 0x07: Left
• 0x08: Right

Appendix

Appendix 1: Weather parameters

Parameter	Code	Type	Weather forecast
Temperature	1 << 0	Integer	No
High temperature	1 << 1	Integer	Yes
Low temperature	1 << 2	Integer	Yes
Humidity	1 << 3	Integer	Yes
Weather condition	1 << 4	A string. See Appendix 3.	Yes
Pressure	1 << 5	Integer	Yes
Sensible temperature	1 << 6	Integer	No
Ultraviolet (UV) index	1 << 7	Integer	Yes
Sunrise	1 << 8	String (format example: 2017-04-24 05:24)	Yes
Sunset	1 << 9	String (format example: 2017-04-24 18:32)	Yes
Wind speed	1 << 12	String (format example: 0.9)	Yes
Wind direction	1 << 13	A string. See Appendix 4.	Yes
Wind speed scale/level	1 << 14	Integer	No
Air quality index	1 << 15	Integer	No
PM10 (inhalable particulate matter)	1 << 16	Integer	No
PM2.5 (fine particulate matter)	1 << 17	Integer	No
Ozone level	1 << 18	Integer	No
Nitrogen dioxide level	1 << 19	Integer	No
Carbon monoxide level	1 << 20	Integer	No
Sulfur dioxide level	1 << 21	Integer	No

Appendix 2: Weather parameter types

WKT_TEMP        = (1 << 0),     /**< temperature. */
WKT_THIHG       = (1 << 1),     /**< high temperature. */
WKT_TLOW        = (1 << 2),     /**< low temperature. */
WKT_HUMIDITY    = (1 << 3),     /**< humidity. */
WKT_CONDITIONNUM   = (1 << 4),     /**< weather condition. */
WKT_PRESSURE    = (1 << 5),     /**< pressure. */
WKT_REALFEEL    = (1 << 6),     /**< sensible temperature. */
WKT_UVI         = (1 << 7),     /**< uvi. */
WKT_SUNRISE     = (1 << 8),     /**< sunrise. */
WKT_SUNSET      = (1 << 9),     /**< sunset. */
WKT_UNIX        = (1 << 10),    /**< unix time, used with sunrise and sunset. */
WKT_LOCAL       = (1 << 11),    /**< local time, used with sunrise and sunset. */
WKT_WINDSPEED   = (1 << 12),    /**< wind speed. */
WKT_WINDDIR     = (1 << 13),    /**< wind direction. */
WKT_WINDLEVEL   = (1 << 14),    /**< wind speed scale/level. */
WKT_AQI         = (1 << 15),    /**< aqi. */
WKT_PM10        = (1 << 16),    /**< pm10. */
WKT_PM25        = (1 << 17),    /**< pm2.5. */
WKT_O3          = (1 << 18),    /**< o3. */
WKT_NO2         = (1 << 19),    /**< no2. */
WKT_CO          = (1 << 20),    /**< co. */
WKT_SO2         = (1 << 21),    /**< so2. */

Appendix 3: Weather conditions

ASCII code w.conditionNum	Hexadecimal value	Weather conditions
120	31 32 30	Sunny
101	31 30 31	Heavy rain
102	31 30 32	Thunderstorm
103	31 30 33	Sandstorm
104	31 30 34	Light snow
105	31 30 35	Snow
106	31 30 36	Freezing fog
107	31 30 37	Rainstorm
108	31 30 38	Isolated shower
109	31 30 39	Dust
110	31 31 30	Thunder and lightning
111	31 31 31	Light shower
112	31 31 32	Rain
113	31 31 33	Sleet
114	31 31 34	Dust devil
115	31 31 35	Ice pellets
116	31 31 36	Strong sandstorm
117	31 31 37	Sand blowing
118	31 31 38	Light to moderate rain
119	31 31 39	Mostly clear
121	31 32 31	Fog
122	31 32 32	Shower
123	31 32 33	Heavy shower
124	31 32 34	Heavy snow
125	31 32 35	Extreme rainstorm
126	31 32 36	Blizzard
127	31 32 37	Hail
128	31 32 38	Light to moderate snow
129	31 32 39	Partly cloudy
130	31 33 30	Light snow shower
131	31 33 31	Moderate snow
132	31 33 32	Overcast
133	31 33 33	Needle ice
134	31 33 34	Downpour
136	31 33 36	Thundershower and hail
137	31 33 37	Freezing rain
138	31 33 38	Snow shower
139	31 33 39	Light rain
140	31 34 30	Haze
141	31 34 31	Moderate rain
142	31 34 32	Cloudy
143	31 34 33	Thundershower
144	31 34 34	Moderate to heavy rain
145	31 34 35	Heavy rain to rainstorm
146	31 34 36	Clear

Appendix 4: Wind direction code

Code (string)	Hexadecimal value	Description
N	4e	North
NNE	4e 4e 45	Northeast by north
NE	4e 45	Northeast
ENE	45 4e 45	Northeast by east
E	45	East
ESE	45 53 45	Southeast by east
SE	53 45	Southeast
SSE	53 53 45	Southeast by south
S	53	South
SSW	53 53 57	Southwest by south
SW	53 57	Southwest
WSW	57 53 57	Southwest by west
W	57	West
WNW	57 4e 57	Northwest by west
NW	4e 57	Northwest
NNW	4e 4e 57	Northwest by north

Appendix 5: Multi-camera switching

Sub frame position

The configuration options will be available as a cloud feature in the future, enabling you to customize display positions.

No position labels displayed

Position labels displayed

Additionally, display the camera position, as shown in the small green box below.

The full data for switching between screens with position labels in the sequence shown in the image above.

Switch	Main frame-0	Sub frame-1	Sub frame-2	Sub frame-3	Full data in hex
Default	Front	Back	Up	Down	0003 0104 0205 0306
First switching	Back	Front	Up	Down	0004 0103 0205 0306
Second switching	Down	Front	Up	Back	0006 0103 0205 0304