RAK12012 WisBlock Heart Rate Sensor Module Datasheet
Overview
Description
The RAK12012, a part of WisBlock Sensor, is an integrated pulse oximetry and heart-rate monitor module used for measuring person's heart rate and oxygen saturation. The sensor attached to this module is MAX30102 from Analog Devices.
Features
- Heart-Rate Monitor and Pulse Oximeter Sensor in LED Reflective Solution
- Ultra-Low Power Operation
- Robust Motion Artifact Resilience
- Fast Data Output Capability
- -40 °C to +85 °C Operating Temperature Range
- 3.3 V Power supply
- Operating Current: 0.7 - 1200 uA
- Chipset: Analog Devices MAX30102
- Module Size: 25 mm x 35 mm
Specifications
Overview
Mounting
The RAK12012 WisBlock Heart Rate Sensor Module can be mounted to the IO slot of the WisBlock Base board. Figure 1 shows the mounting mechanism of the RAK12012 on a WisBlock Base module.
Figure 2408: RAK12012 WisBlock Heart Rate Sensor Module MountingWith the RAK19008 FPC Cable，RAK12012 can separated from the WisBlock Base board. The two (2) slots of the board are for the rubber bands. The rubber bands can help to press the sensor against the finger or wrist.
Figure 2409: RAK12012 WisBlock Heart Rate Sensor Module Mounting With Rubber BandHardware
The hardware specification is categorized into five parts. It shows the chipset of the module and discusses the pinouts and its corresponding functions and diagrams. It also covers the electrical and mechanical parameters that include the tabular data of the functionalities and standard values of the RAK12012 WisBlock Heart Rate Sensor Module.
Chipset
| Vendor | Part number |
|---|---|
| Analog Devices | MAX30102 |
Pin Definition
The RAK12012 WisBlock Heart Rate Sensor comprises a standard WisBlock connector. The WisBlock connector allows the RAK12012 module to be mounted to a WisBlock Base board. The pin order of the connector and the pinout definition is shown in Figure 3.
- I2C related pins: INT,3V3_S, and GND are connected to WisIO connector.
- 3V3_S voltage output from the WisBlock Base that powers the RAK12012 module can be controlled by the WisBlock Core via WB_IO2 (WisBlock IO2 pin). This makes the module ideal for low-power IoT projects since the WisBlock Core can totally disconnect the power of the RAK12012 module.
Figure 2410: RAK12012 WisBlock Heart Rate Sensor Module PinoutElectrical Characteristics
Absolute Maximum Ratings
| Parameter | Minimum | Maximum | Unit |
|---|---|---|---|
| 3V3_S | -0.3 | 6 | V |
| 1V8 | -0.3 | 2.2 | V |
| ESD (HBM) | - | 2.5 | KV |
| Operating Temperature Range | -40 | 85 | °C |
| Continuous Power Dissipation | - | 440 | mW |
Power Supply Ratings
| Symbol | Description | Condition | Min. | Nom. | Max. | Unit |
|---|---|---|---|---|---|---|
| 3V3_S | LED Supply Voltage | Input voltage must within this range | 3.1 | 3.3 | 5 | V |
| 1V8 | Analog Supply Voltage | Input voltage must within this range | 1.7 | 1.8 | 2 | V |
| IDD1 | Supply Current | SpO2 and HR mode，PW = 215 µs，50 sps | - | 600 | 1200 | uA |
| IDD2 | Supply Curren | IR only mode, PW = 215 µS, 50 sps | - | 600 | 1200 | uA |
| ISHDN | Supply Current in Shutdown | TA = +25 °C, MODE = 0x80 | - | 0.7 | 10 | uA |
Mechanical Characteristics
Board Dimensions
Figure 4 shows the dimensions and the mechanical drawing of the RAK12012 module.
Figure 2411: RAK12012 WisBlock Heart Rate Sensor Module DimensionsWisConnector PCB Layout
Figure 2412: WisConnector PCB Footprint and RecommendationsSchematic Diagram
Power Supply
Figure 6 shows the MAX30102 power supply. The IC uses 1.8 V as voltage supply source generated by SGM2019-1.8YN5G/TR (LDO). The VLED+ has a different dedicated power supply coming from the 3V3_S of the WisBlock Base board.
Figure 2413: RAK12012 WisBlock Heart Rate Sensor Module Power SupplyVoltage Level Transfer
The MAX30102 IO voltage is 1.8 V and the CPU module voltage is 3.3 V, so the voltage level transfer is needed. Pull-up Resistor for I2C_SCL and I2C_SDA already exist on WisBlock Base board，so there is no need to connect（NC）on IO module such as RAK12012.
Figure 2414: The Voltage Level Transfer CircuitMAX30102EFD+T Circuit
INT is an active-low interrupt (Open-Drain). This needs to be connected to an external voltage with a pull-up resistor R7.
Figure 2415: MAX30102EFD+T CircuitWisConnector
Figure 2416: RAK12012 Module WisConnector- The I2C related pins: **INT **,3V3_S, and GND are connected to WisIO connector.
- The 3V3_S supply can be disconnected to save power via WB_IO2.
