Seeed Studio Mr60bha1 Mmwave Breathing And Heartbeat Module User Manual

MR60BHA1 mmWave Breathing and Heartbeat Module
User Manual

MR60BHA1
60GHz mmWave Module – Respiratory
Heartbeat Detection
Sensor User Manual (V1.9)

Overview

This document focuses on the use of the radar, the issues that need to be paid attention to in each phase, to minimize the design cost and increase the stability of the product, and to improve the efficiency of the project completion. This document focuses on the issues that need to be taken into account in each phase, in order to minimize the design cost and increase the stability of the product, and to improve the efficiency of the project completion.
From hardware circuit reference design, radar antenna and housing layout requirements, how to distinguish interference and multi-functional standard UART protocol output. The radar is a self-contained system.
This radar is a self-contained space sensing sensor, which consists of RF antenna, radar chip and high speed MCU. The radar is a self-contained sensor with a combination of RF antenna, radar chip and high-speed main frequency MCU. It can be equipped with a host computer or host computer to flexibly output detection status and data, and meet the needs of several groups of GPIOs. It can be equipped with a host computer or a host computer to flexibly output detection status and data, and meet several groups of GPIOs for user customization and development.

Working Principle

The radar transmits a 60G band millimeter wave signal, and the target reflects the electromagnetic wave signal, and demodulates it from the transmitted signal. The signal is demodulated, then amplified, filtered, ADC and other processing to obtain the echo demodulation signal data. In the MCU unit, the amplitude, frequency and phase of the echo signal are decoded, and the target signal is finally decoded. The target parameters (sleep quality, respiration, tossing, body movement, etc.) are measured and evaluated in the MCU.

Hardware Design Considerations

The rated supply voltage of the radar needs to meet 4.9 – 6V, and the rated current needs to be 200mA or more input is required. The power supply is designed to have a ripple of 100mv.
2.1 Power supply can refer to the following circuit design

2.2 Wiring Diagram

Figure 3 Module and peripheral wiring diagram

Antenna and housing layout requirements

PCBA: Need to keep the radar patch height 1mm higher than other devices
Housing structure: need to keep the radar antenna surface and the housing surface have 2 – 5mm distance
Housing detection surface: non-metallic housing, need to be straight to avoid bending surface, affect the performance of the whole sweep surface area Performance

Electrostatic protection

Radar products with electrostatic sensitive circuitry inside, vulnerable to electrostatic hazards, so need to be in transport, storage, work and handling process to do a good job of electrostatic protection, do not touch the grasp of the radar hands. Therefore, it is necessary to do a good job in the transportation, storage, work and picking up process of static protection, do not touch and grab the radar module antenna surface and connector pins, only touch the corners. Do not touch the surface of the radar module antenna and connector pins with your hands, only touch the corners.
When handling the radar sensor, please wear anti-static gloves as much as possible.

Detailed explanation of functions

5.1 Function Description

Protocol Description

This protocol is applied to the communication between the 60G millimeter wave respiratory sleep detection radar and the host computer.
This protocol outlines the radar workflow, briefly introduces the interface protocol composition architecture, and The interface protocol structure is briefly introduced, and the related radar work requires control commands and data.
Interface level: TTL
Baud rate: 115200bps
Stop bit: 1
Data bits: 8
Parity check: None

Communication command and parameter definition

7.1 Frame structure definition and description
7.1.1 Definition of frame structure

7.1.2 Description of the frame structure
a. Frame header: 2 Byte, fixed to 0x53,0x59;
b. Control word: 1 Byte
(0x01 – heartbeat packet identification, 0x02 – product information, 0x03 – OTA upgrade, 0x05 – operation status, 0x07 – radar detection range information, 0x80 – human presence, 0x81 – breath detection, 0x84 – sleep monitoring, 0x85 – heart rate monitoring)
c. Command word: 1 Byte (to identify the current data content)
d. Length identification: 2 Byte, equal to the specific byte length of the data
e. Data: n Byte, defined according to the actual function
f. Checksum: 1 Byte. (Calculation method of checksum: “frame header + control word + command word + length identifier + data” summed to the lower eight bits) g. End of frame: 2Byte, fixed to 0X54,0X43;
7.2 Description of address assignment and data information

Appendix 1: About the calculation of check digit

Let’s take the command to send a human presence information query as an example.
The data construction for the presence information query confirmed by the protocol table above is
Frame header: 0x53 0x59
Control word: 0x80
Command word: 0x81
Length identifier: 0x00 0x01
Data: 0x0F
Checksum: 1Byte (SUM)
End of frame: 0x54 0x43
Combined into a complete instruction as follows
53 59 80 81 00 01 0F sum 54 43
Check digit sum : 0x53 + 0x59 + 0x80 + 0x81 + 0x01 + 0x0F
(0x53 + 0x59 + 0x80 + 0x81 + 0x00 + 0x01 + 0x0F) = 0x01BD
The lower byte is sum = 0xBD
So the complete existence information query instruction is: 53 59 80 81 00 01 0F BD 54