HWT101 Protocol
HWT101 Protocol
Instructions for use：
The serial port sending command must be completed within 10S, otherwise it will be automatically locked. To avoid automatic locking, the following steps can be performed.
1. Enter the unlock command
2. Enter the command that needs to modify or read the data
3. Save the command
Register
ADDR (Hex) | ADDR (Dec) | REGISTER NAME | FUNCTION | SERIAL I/F | Bit15 | Bit14 | Bit13 | Bit12 | Bit11 | Bit10 | Bit9 | Bit8 | Bit7 | Bit6 | Bit5 | Bit4 | Bit3 | Bit2 | Bit1 | Bit0 |
00 | 00 | SAVE | save/rebbot/reset | R/W | SAVE[15:0] | |||||||||||||||
03 | 03 | RRATE | output rate | R/W | RRATE[3:0] | |||||||||||||||
04 | 04 | BAUD | Serial port baud rate | R/W | BAUD[3:0] | |||||||||||||||
1A | 26 | IICADDR | device address | R/W | IICADDR[7:0] | |||||||||||||||
1B | 27 | LEDOFF | turn off LED light | R/W | LEDOFF | |||||||||||||||
27 | 39 | READADDR | Read registers | R/W | READADDR[7:0] | |||||||||||||||
2E | 46 | VERSION | version number | R | VERSION[15:0] | |||||||||||||||
30 | 48 | YYMM | year/mouth | R/W | MOUTH[15:8] | YEAR[7:0] | ||||||||||||||
31 | 49 | DDHH | day/hour | R/W | HOUR[15:8] | DAY[7:0] | ||||||||||||||
32 | 50 | MMSS | minute/seconds | R/W | SECONDS[15:8] | MINUTE[7:0] | ||||||||||||||
33 | 51 | MS | millisecond | R/W | MS[15:0] | |||||||||||||||
38 | 56 | GY | Angular velocityY | R | GY[15:0] | |||||||||||||||
39 | 57 | GZ | Angular velocityZ | R | GZ[15:0] | |||||||||||||||
3F | 63 | Yaw | Heading angle | R | Yaw[15:0] | |||||||||||||||
41 | 65 | AUTOPTP | Automatically obtain zero bias peak-to-peak | R/W | AUTOPTP[15:0] | |||||||||||||||
43 | 67 | AUTOT | Automatically obtain zero bias time | R/W | AUTOT[15:0] | |||||||||||||||
44 | 68 | AUTOTH | Automatically obtain zero bias threshold | R/W | AUTOTH[15:0] | |||||||||||||||
48 | 72 | WORKMODE | working mode | R/W | WORKMODE[2:0] | |||||||||||||||
4A | 74 | GYROPTP | Z-axis static peak-to-peak | R/W | GYROPTP[15:0] | |||||||||||||||
4B | 75 | GPTPTIME | Z-axis peak-to-peak acquisition time | R/W | GPTPTIME[15:0] | |||||||||||||||
4C | 76 | GYROBAIS | Z-axis zero bias value | R/W | GYROBAIS[15:0] | |||||||||||||||
4D | 77 | GBAISTIME | Z-axis zero bias acquisition time | R/W | GYROBAIS[15:0] | |||||||||||||||
4E | 78 | GSTATICTHRE | Z-axis static threshold | R/W | GSTATICTHRE[15:0] | |||||||||||||||
4F | 79 | GSTATICTIME | Z-axis stabilization time | R/W | GSTATICTIME[15:0] | |||||||||||||||
50 | 80 | PGSCALE | Z-axis calibration factor P | R/W | PGSCALE[15:0] | |||||||||||||||
52 | 82 | GSCALERANGE | Z-axis calibration angle | R/W | GSCALERANGE[15:0] | |||||||||||||||
61 | 97 | GYROCALITHR | Static detection threshold | R/W | GYROCALITHR[15:0] | |||||||||||||||
63 | 99 | GYROCALTIME | Gyro auto calibration time | R/W | GYROCALTIME[15:0] | |||||||||||||||
6A | 106 | WERROR | Gyroscope change value | R/W | GYROPTP[15:0] | |||||||||||||||
6E | 110 | WZTIME | Angular velocity continuous rest time | R/W | WZTIME[15:0] | |||||||||||||||
6F | 111 | WZSTATIC | Angular velocity integral threshold | R/W | WZSTATIC[15:0] | |||||||||||||||
74 | 116 | MODDELAY | 485 data response delay | R/W | MODDELAY[15:0] | |||||||||||||||
76 | 118 | CALIYAW | Z axis angle to zero | R/W | CALIYAW[15:0] |
Read format
Data is sent in hexadecimal, not ASCII.
Each data is transmitted in sequence by low byte and high byte, and the two are combined into a signed short type of data. For example, for data DATA1, DATA1L is the low byte and DATA1H is the high byte. The conversion method is as follows:
Assuming that DATA1 is the actual data, DATA1H is the high byte part, and DATA1L is the low byte part, then: DATA1=(short)((short)DATA1H<<8|DATA1L). It must be noted here that DATA1H needs to be coerced into a signed short type of data before shifting, and the data type of DATA1 is also a signed short type, so that negative numbers can be represented.
protocol head | Data content | Data lower 8 bits | Data high 8 bits | Data lower 8 bits | Data high 8 bits | Data lower 8 bits | Data high 8 bits | Data lower 8 bits | Data high 8 bits | SUMCRC |
0x55 | TYPE【1】 | DATA1L[7:0] | DATA1H[15:8] | DATA2L[7:0] | DATA2H[15:8] | DATA3L[7:0] | DATA3H[15:8] | DATA4L[7:0] | DATA4H[15:8] | SUMCRC【2】 |
【1】TYPE(Data content):
TYPE | Remark |
0x52 | Angular velocity |
0x53 | Angle |
【2】SUMCRC(data and checksum)：
SUMCRC=0x55+TYPE+DATA1L+DATA1H+DATA2L+DATA2H+DATA3L+DATA3H+DATA4L+DATA4H
SUMCRC is a char type, taking the lower 8 bits of the checksum
Angular velocity
0x55 | 0x52 | 0x00 | 0x00 | WyL | WyH | WzL | WzH | 0x00 | 0x00 | SUM |
Name | Description | Remark | ||||||||
0x00 | meaningless | |||||||||
0x00 | meaningless | |||||||||
WzL | Angular velocity Z low 8 bits | Angular velocity Z=((WzH<<8)|WzL)/32768*2000°/s【1】 | ||||||||
WzH | Angular velocity Z high 8 bits | |||||||||
WzL | Angular velocity Z low 8 bits | Angular velocity Z=((WzH<<8)|WzL)/32768*2000°/s【2】 | ||||||||
WzH | Angular velocity Z high 8 bits | |||||||||
0x00 | meaningless | |||||||||
0x00 | meaningless | |||||||||
SUM | Checksum | SUM=0x55+0x52+WyL+WyH+WzL+WzH |
【1】Raw data of angular velocity Z
【2】 The angular velocity Z obtained after the original data of the angular velocity Z is calibrated
Angle output
0x55 | 0x53 | RollL | RollH | PitchL | PitchH | 0x00 | 0x00 | VL | VH | SUM |
Name | Description | Remark | ||||||||
0x00 | Meaningless | |||||||||
0x00 | Meaningless | |||||||||
0x00 | Meaningless | |||||||||
0x00 | Meaningless | |||||||||
YawL | Yaw angle Z low 8 bits | yaw angle Z=((YawH<<8)|YawL)/32768*180(°) | ||||||||
YawH | Yaw angle Z high 8 bits | |||||||||
VL | Version number lower 8 bits | Version number calculation formula: version number=(VH<<8)|VL | ||||||||
VH | Version number high 8 bits | |||||||||
SUM | checksum | SUM=0x55+0x53+YawH+YawL+VL+VH |
Read format
The following data, all using Hex code in hexadecimal
All settings need to operate the unlock register (KEY) first
protocol header | protocol header | register | Data lower 8 bits | Data high 8 bits |
0xFF | 0xAA | ADDR | DATAL[7:0] | DATAH[15:8] |
Data is sent in hexadecimal, not ASCII.
Each data is transmitted in sequence by low byte and high byte, and the two are combined into a signed short type of data. For example, data DATA, where DATAL is the low byte and DATAH is the high byte. The conversion method is as follows:
Assuming that DATA is the actual data, DATAH is its high-byte part, and DATAL is its low-byte part, then: DATA=(short)((short)DATAH<<8|DATAL). It must be noted here that DATAH needs to be coerced into a signed short type of data before shifting, and the data type of DATA is also a signed short type, so that negative numbers can be represented.
SAVE (save/reboot/reset)
Register Name: SAVE Register Address: 0 (0x00) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | SAVE[15:0] | Save: 0x0000 Reboot: 0x00FF Factory reset: 0x0001 |
Example: FF AA 00 FF 00 (reboot) |
RRATE（output rate）
Register Name: RRATE Register Address: 3 (0x03) Read and write direction: R/W Default: 0x0006 | ||
Bit | NAME | FUNCTION |
15:4 | ||
3:0 | RRATE[3:0] | set output rate： 0001(0x01): 0.2Hz 0010(0x02): 0.5Hz 0011(0x03): 1Hz 0100(0x04): 2Hz 0101(0x05): 5Hz 0110(0x06): 10Hz 0111(0x07): 20Hz 1000(0x08): 50Hz 1001(0x09): 100Hz 1011(0x0B): 200Hz 1011(0x0C): 500Hz |
Example: FF AA 03 03 00 (set 1Hz output) |
BAUD RATE（Serial port baud rate）
Register Name: BAUD Register Address: 4 (0x04) Read and write direction: R/W Default: 0x0002 | ||
Bit | NAME | FUNCTION |
15:4 | ||
3:0 | BAUD[3:0] | Set serial port baud rate： 0001(0x01): 4800bps 0010(0x02): 9600bps 0011(0x03): 19200bps 0100(0x04): 38400bps 0101(0x05): 57600bps 0110(0x06): 115200bps 0111(0x07): 230400bps |
Example: FF AA 04 06 00 (set serial port baud rate 115200) |
IIC ADDRESS（Device address）
Register Name: IICADDR Register Address: 26 (0x1A) Read and write direction: R/W Default: 0x0050 | ||
Bit | NAME | FUNCTION |
15:8 | ||
7:0 | IICADDR[7:0] | Set the device address for I2C use 0x01~0x7F |
Example: FF AA 1A 02 00 (set the device address to 0x02) |
LEDOFF（turn off LED light）
Register Name: LEDOFF Register Address: 27 (0x1B) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:1 | ||
0 | LEDOFF | 1: turn off LED light 0: open up LED light |
Example: FF AA 1B 01 00 (turn off the LED light) |
READADDR（Read registers）
Register Name: READADDR Register Address: 39 (0x27) Read and write direction: R/W Default: 0x00FF | ||
Bit | NAME | FUNCTION |
15:8 | ||
7:0 | READADDR[7:0] | Read register range: Please refer to "Register Table" |
Example: Send: FF AA 27 34 00 (read acceleration X-axis 0x34) Return: 55 5F AXL AXH AYL AYH AZL AZH GXL GXH SUM For details, please refer to "Read Register Return Value" in the "Read Format" chapter |
VERSION（version number）
Register Name: VERSION Register Address: 46 (0x2E) Read and write direction: R Default: none | ||
Bit | NAME | FUNCTION |
15:0 | VERSION[15:0] | Different products, different version numbers |
Example: Send: FF AA 27 2E 00 (read version number, 0x27 means read, 0x2E is version number register) Return: 55 5F VL VH XX XX XX XX XX XX SUM VERSION[15:0]=(short)(((short)VH<<8)|VL) |
YYMM~MS（on-chip time）
Register Name: YYMM~MS Register address: 48~51 (0x30~0x33) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:8 | YYMM[15:8] | mouth |
7:0 | YYMM[7:0] | year |
15:8 | DDHH[15:8] | hour |
7:0 | DDHH[7:0] | day |
15:8 | MMSS[15:8] | seconds |
7:0 | MMSS[7:0] | minute |
15:0 | MS[15:0] | millisecond |
Example: FF AA 30 16 03 (set year 22-03) FF AA 31 0C 09 (set date 12-09) FF AA 32 1E 3A (set minute seconds 30:58) FF AA 33 F4 01 (set ms 500) Example: Send: FF AA 27 30 00 (read version number, 0x27 means read, 0x30 is year month register) Returns: 55 5F YYMM[7:0] YYMM[15:8] DDHH[7:0] DDHH[15:8] MMSS[7:0] MMSS[15:8] MS[7:0] MS[15: 8] SUM |
GY~GZ（Angular velocity）
Register Name: GY~GZ Register address: 56~57 (0x38~0x39) Read and write direction: R Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | GY[15:0] | Angular velocity Y=GY[15:0]/32768*2000°/s【1】 |
15:0 | GZ[15:0] | Angular velocity Z=GZ[15:0]/32768*2000°/s【2】 |
[1] Raw data of angular velocity Z
[2] The angular velocity Z obtained after the original data of the angular velocity Z is calibrated
Yaw（yaw angle）
Register Name: Yaw Register Address: 63 (0x3F) Read and write direction: R Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | Yaw[15:0] | yaw angle Z=Yaw[15:0]/32768*180° |
WORKMODE（Z-axis operation mode）
Register Name: WORKMODE Register Address: 72 (0x48) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:4 | ||
3:0 | WORKMODE[3:0] | Set the Z-axis operation mode: 0000(0x00): normal data mode 0001(0x01): peak-to-peak mode 0010(0x02): seek zero offset mode 0011 (0x03): find scale factor mode |
Example: Send: FF AA 48 01 00 (Automatically obtain zero bias) |
GYROPTP（Z-axis static peak-to-peak）
Register Name: GYROPTP Register Address: 74 (0x4A) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | GYROPTP[15:0] | Parameters used in calculating zero bias, no need to set for sensor automatic acquisition |
Write 0x01 to the "WORKMODE" register to enter the "peak-to-peak mode", in this mode the sensor automatically calculates the maximum and minimum values of the Z-axis angular velocity within the time set by "GPTPTIME" and records them in "GYROPTP". In "Zero Offset Mode", this data will be used to calculate and filter the zero offset. Z-axis static peak-to-peak value = GYROPTP/1000 (°/s) Example: Send: FF AA 27 4A 00 (read Z-axis static peak-to-peak value) Return: 55 5F 64 00 XX XX XX XX XX XX SUM 0x0064=100, Z-axis static peak-to-peak value = 100/1000=0.1 (°/s) |
GPTPTIME（Z-axis peak-to-peak acquisition time）
Register Name: GPTPTIME Register Address: 75 (0x4B) Read and write direction: R/W Default: 0x000A | ||
Bit | NAME | FUNCTION |
15:0 | GPTPTIME[15:0] | Calculate the peak-to-peak time, the default is 10S |
Example: Send: FF AA 4B 0A 00 (set the Z-axis peak-to-peak acquisition time to 10S) After entering the "Peak-to-Peak Mode", obtain the difference between the maximum value and the minimum value of the Z-axis angular velocity within the "GPTPTIME" time, store it in "GYROPTP", and use this data for zero bias in the "Zero Bias Mode". calculation filter. |
GYROBAIS（Z axis zero bias value）
Register Name: GYROBAIS Register Address: 76 (0x4C) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | GYROBAIS[15:0] | The zero bias value of the horizontal gyroscope, which can be obtained through the "Zero Bias Mode" |
The Z-axis horizontal gyroscope has a certain zero bias value when placed at rest, and the angular velocity at rest can be eliminated by this zero bias value. The zero offset value can be automatically calculated by automatically obtaining the zero offset. Enter the "Zero Offset Mode" to automatically calculate the zero offset value according to the peak-to-peak value of "GYROPTP" and the "GBAISTIME" offset acquisition time. Z axis zero bias value = GYROBAIS/1000 (°/s) Example: Send: FF AA 27 4C 00 (read Z-axis static peak-to-peak value) Return: 55 5F 64 00 XX XX XX XX XX XX SUM 0x0064=100, Z-axis static peak-to-peak value = 100/1000=0.1 (°/s) |
GBAISTIME（Z axis zero offset acquisition time）
Register Name: GBAISTIME Register Address: 77 (0x4D) Read and write direction: R/W Default: 0x000A | ||
Bit | NAME | FUNCTION |
15:0 | GBAISTIME[15:0] | Time required to calculate the zero bias value of the horizontal gyroscope |
Example: Send: FF AA 4D 0A 00 (set the Z-axis zero bias acquisition time to 10S) The time required to obtain the Z-axis zero bias, and the zero bias value is obtained according to this time when the zero bias is obtained. |
GSTATICTHRE（Z-axis stillness threshold）
Register Name: GSTATICTHRE Register Address: 78 (0x4E) Read and write direction: R/W Default: 0x0032 | ||
Bit | NAME | FUNCTION |
15:0 | GSTATICTHRE[15:0] | The larger the GSTATICTHRE[15:0], the weaker the seismic performance and the smaller the error The smaller the GSTATICTHRE[15:0], the better the seismic performance and the larger the error. Default value 50 |
The Z-axis horizontal gyroscope has slight data jitter when it is placed at rest. This parameter can filter out these slight jitters. When the angular velocity is less than the "GSTATICTHRE" setting value and lasts for the time set by "GSTATICTIME", it is regarded as stationary, and the Z-axis angular velocity is zero. This parameter can be appropriately increased when it is used in scenes with jitter and the Z-axis is accumulated due to jitter, and this parameter can be appropriately decreased in scenes with very slow and uniform rotation. Z axis zero bias value = GSTATICTHRE/1000 (°/s) Example: Send: FF AA 4E 64 00 ((set the Z axis static threshold 0.1g), 0x0064=100, 100/10000=0.1(°)) |
GSTATICTIME（Z-axis settling time）
Register Name: GSTATICTIME Register Address: 79 (0x4F) Read and write direction: R/W Default: 0x0064 | ||
Bit | NAME | FUNCTION |
15:0 | GSTATICTIME[15:0] | Z-axis judges the still time |
Z-axis static judgment time threshold. It is considered stationary when the angular velocity is less than the value set by "GSTATICTHRE" for the time set by "GSTATICTIME". If the stabilization time is required to be higher, this parameter can be adjusted appropriately. Lowering this parameter can speed up settling time but may also increase error. Z-axis stabilization time = GSTATICTIME/1000 (s) Example: Send: FF AA 4F 32 00 ((set the Z axis stabilization time to 0.05s), 0x0032=50, 50/10000=0.05(°)) |
PGSCALE（Z-axis calibration factor P）
Register Name: PGSCALE Register Address: 80 (0x50) Read and write direction: R/W Default: 0x2710 | ||
Bit | NAME | FUNCTION |
15:0 | PGSCALE[15:0] | Range：0~20000 This parameter is written in the factory using a high-precision turntable, please do not modify it |
There is an error in the measurement of the Z-axis gyroscope, and a high-precision turntable will be used to measure this error when leaving the factory, and this parameter will be written into the sensor. Do not modify this parameter unless necessary. This parameter can be automatically calculated in the "scale factor mode". After entering the "scale factor mode", rotate the sensor by the angle set by "GSCALERANGE" to calculate the calibration factor. Z-axis calibration factor P=PGSCALE/10000.0 Example: Send: FF AA 27 50 00 (read Z-axis calibration factor P) Return: 55 5F 74 27 XX XX XX XX XX XX SUM 0x2774 = 10100, read Z-axis calibration factor P = 10100/10000=1.01 |
GSCALERANGE（Z-axis angle calibration range）
Register Name: GSCALERANGE Register Address: 82 (0x52) Read and write direction: R/W Default: 0x02D0 | ||
Bit | NAME | FUNCTION |
15:0 | GSCALERANGE[15:0] | When calibrating the factor, it needs to be calibrated according to this parameter |
Example: Send: FF AA 52 68 01 ((set Z-axis calibration angle 360), 0x0168=360) The required rotation angle of the Z axis in the "scale factor mode" is generally set to an integer multiple of 360°. |
GYROCALITHR（Gyro Rest Threshold）
Register Name: GYROCALITHR Register Address: 97 (0x61) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | GYROCALITHR[15:0] | Set the gyroscope inactivity threshold: Gyro Gyro Still Threshold=GYROCALITHR[15:0]/1000(°/s) |
Example: FF AA 61 32 00 (set the gyro static threshold to 0.05°/s, 0x0032=50, 50/1000=0.05(°/s)) When the angular velocity change is less than 0.05°/s and lasts for the time of "GYROCALTIME", the sensor recognizes it as stationary and automatically resets the angular velocity less than 0.05°/s to zero The setting rule of the static threshold of the gyroscope can be determined by reading the value of the "WERROR" register. The general setting rule is: GYROCALITHR=WERROR*1.2, unit: °/s This register needs to be used in conjunction with the GYROCALTIME register |
GYROCALTIME(Gyro auto calibration time)
Register Name: GYROCALTIME Register Address: 99 (0x63) Read and write direction: R/W Default: 0x03E8 | ||
Bit | NAME | FUNCTION |
15:0 | GYROCALTIME[15:0] | Set gyroscope auto-calibration time |
Example: Set gyroscope auto-calibration time to 500ms FF AA 63 F4 01 When the angular velocity change is less than "GYROCALITHR" and lasts for 500ms, the sensor recognizes that it is stationary and automatically resets the angular velocity less than 0.05°/s to zero This register needs to be used in conjunction with the GYROCALITHR register |
WERROR（Gyroscope change value）
Register Name: WERROR Register Address: 106 (0x6A) Read and write direction: R Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | WERROR[15:0] | Gyroscope change value=WERROR[15:0]/1000*180/3.1415926(°/s) When the sensor is stationary, the "GYROCALITHR" register can be set by changing this register |
WZTIME（Angular velocity continuous rest time）
Register Name: WZTIME Register Address: 110 (0x6E) Read and write direction: R/W Default: 0x01F4 | ||
Bit | NAME | FUNCTION |
15:0 | WZTIME[15:0] | Angular velocity continuous rest time |
Example: Set the angular velocity continuous static time to 500ms FFAA 6E F4 01 When the angular velocity is less than "WZSTATIC" and lasts for 500ms, the angular velocity output is 0, and the Z-axis heading angle is not integrated This register needs to be used in conjunction with the "WZSTATIC" register |
WZSTATIC（Angular velocity integral threshold)
Register Name: WZSTATIC Register Address: 111 (0x6F) Read and write direction: R/W Default: 0x012C | ||
Bit | NAME | FUNCTION |
15:0 | WZSTATIC[15:0] | Angular velocity integral threshold=WZSTATIC[15:0]/1000(°/s) |
Example: Set the angular velocity integration threshold to 0.5°/s FF AA 6F F4 01 When the angular velocity is greater than 0.5°/s, the Z-axis heading angle starts to integrate the acceleration When the angular velocity is less than 0.5°/s, and the duration set by the register "WZTIME", the angular velocity output is 0, and the Z-axis heading angle is not integrated This register needs to be used in conjunction with the "WZTIME" register |
CALIYAW（Z-axis angle to zero）
Register Name: CALIYAW Register address: 118(0x76) Read and write direction: R/W Default: 0x0000 | ||
Bit | NAME | FUNCTION |
15:0 | CALIYAW[15:0] | Set the Z-axis to zero: 0 (0x00): Z-axis returns to zero |
Example: FF AA 76 00 00 (Z-axis angle return to zero) |
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