What is the Device Interface Definition of FOG North Seeker

1.Application products

ER-FNS-03 Low Cost 3 Axis FOG North Seeker

2.1 Data Interface

The SX1 connector leads to a J30J-21ZK connector, which is connected to a standard four-wire RS422. Users only need to connect the above serial port to the acquisition computer for measurement. Note that the baud rate is 614.4 kbps, which requires a matching acquisition device for data acquisition.

2. 2 Wiring definition

Table 5 Wiring definition：J30J-21ZK

No.	J30 Pin	North Finder Connection Point	Definition	Remarks
1	1	DY-6V_9V	+12V	Powered by
2	2	DY-GND6	GND	Powered by
6	6	DHB-BT+	T+	LED Digital Tube
7	7	DHB-GND	GND	LED Digital Tube
8	8	DHB-DT+	T+	422
9	9	DHB-DT-	T-
10	10	DHB-DR-	R-
11	11	DHB--DR+	R+

2.3 Data Receiving Protocol From North seeker to Computer

ER-FNS-03 series north finder adopts RS422 serial port output. The baud rate is 19200bps. Each frame has a total of 60 bytes. Each byte contains 1 start bit (0), 8 data bits, 1 stop bit (1), each word. The lower part is transmitted first in the section, and the low byte is transmitted first for each frame of data, and there is no verification at this moment. The specific data format is shown in the following table:

Table 6 data frame format

Bytes (60 bytes in Total)	Data content	Supplementary explanation
1~4	Frame header	0X EB8055AA
5~8	X Gyro Data	Low first and then high，Dimensionless digital quantity
9~12	Y Gyro Data	Low first and then high，Dimensionless digital quantity
13~16	Z Gyro Data	Low first and then high，Dimensionless digital quantity
17~20	X Accelerometer data	Low first and then high，Dimensionless digital quantity
21~24	Y Accelerometer data	Low first and then high，Dimensionless digital quantity
25~28	Z Accelerometer data	Low first and then high，Dimensionless digital quantity
29~32	latitude	Low first and then high，0.000001°
33~36	longitude	Low first and then high，0.000001°
37~40	height	Low first and then high，1m
41~44	counter	Low first and then high，2.5ms
45~46	Pitch angle/tilt angle	Low first and then high，0.01°
47~48	Roll angle	Low first and then high，0.01°
49~50	Heading/azimuth	Low first and then high，0.01°
51~56	Pending byte
57~60	End of frame	0X FF000034

2.4 Data Transmit Protocol From Computer to North seeker

2.4.1 Total number of bytes delivered at a time: 21 bytes, baud rate 19200bps, no parity check. Each byte contains the start bit (0), data bit (8), and stop bit (1).

Start the work

Byte Number	Definition	Remark
1	0xEB
2	0x80
3	0x00
4	0xCC
5-8	0x00
9-12	0x00
13-16	0x00
17-21	0x00

2.4.2 Send warp and weft height

Byte Number	Definition	Remark
1	0xEB
2	0x80
3	0x00
4	0xAA
5-8	latitude
9-12	longitude
13-16	highly
17	0xAA
18	0xBB
19	0xCC
20	0xDD
21	5 to 20 XOR check

Determine the definition of the data sent according to byte 4:

If control_FLAG ==0xCC: Restarts
If control_FLAG ==0xAA: Indicates the altitude of the latitude and longitude to be sent

Send order: 5-8 bytes: latitude (* 1E6, unit °)

9-12 bytes: Longitude (* 1E6, in °)

13-16 bytes: Height (*1, in m)

For example, C code that sends Latitude and longitude instructions (the rest of the byte configuration is arbitrary), Latitude is "Latitude *1e6", longitude is similar, height ratio is 1.

bytSend[0] = 0xeb;

bytSend[1] = 0x80;

bytSend[2] = 0x00;

bytSend[3] = 0xaa;

bytSend[4] = (Latitude>>24) & 0xff;

bytSend[5] = (Latitude>>16) & 0xff;

bytSend[6] = (Latitude>>8) & 0xff;

bytSend[7] = (Latitude) & 0xff;

bytSend[8] = (Longitude>>24) & 0xff;

bytSend[9] = (Longitude>>16) & 0xff;

bytSend[10] = (Longitude>>8) & 0xff;

bytSend[11] = (Longitude) & 0xff;