Manual

UART Fingerprint Sensor (C)
V1.0 www.waveshare.com 9 / 18
Byte
1
2
3
4
5
6
7
8
CMD
0xF5
0x0A
User
ID(High
8Bit )
User
ID(Low8Bit )
0
0
CHK
0xF5
ACK
0xF5
0x0A
0
0
Permission
(1/2/3)
ACK_NOUSER
0
CHK
0xF5
13. Set/Query comparison level（CMD/ACK both 8 Byte）
Byte
1
2
3
4
5
6
7
8
CMD
0xF5
0x28
0
Byte5=0: New Level
Byte5=1: 0
0：Set Level
1：Query Level
0
CHK
0xF5
ACK
0xF5
0x28
0
Current Level
ACK_SUCCUSS
ACK_FAIL
0
CHK
0xF5
Notes：Comparison level can be 0~9, larger the value, stricter the comparison. Default 5
14. Acquire image and upload（CMD=8 Byte/ACK >8 Byte）
CMD Format：
Byte
1
2
3
4
5
6
7
8
CMD
0xF5
0x24
0
0
0
0
CHK
0xF5
ACK Format：
1）Data head：
Byte
1
2
3
4
5
6
7
8
ACK
0xF5
0x24
Hi(Len)
Low(Len)
ACK_SUCCUSS
ACK_FAIL
ACK_TIMEOUT
0
CHK
0xF5
2）Data packet
Byte
1
2---Len+1
Len+2
Len+3
ACK
0xF5
Image data
CHK
0xF5
Notes：
In DSP module, the pixels of fingerprint image are 280*280, every pixel is represented by 8
bits. When uploading, DSP is skip pixels sampling in horizontal/vertical direction to reduce data
size, so that the image became 140*140, and just take the high 4 bits of pixel. each two pixels
composited into one byte for transferring (previous pixel high 4-bit, last pixel low 4-pixe).
Transmission starts line by line from the first line, each line starts from the first pixel, totally
transfer 140* 140/ 2 bytes of data.
Data length of image is fixed of 9800 bytes.
15. Acquire image and upload eigenvalues（CMD=8 Byte/ACK > 8Byte）
CMD Format：
Byte
1
2
3
4
5
6
7
8
CMD
0xF5
0x23
0
0
0
0
CHK
0xF5
ACK Format：
1）Data head：