アプリケーションノート 6557

How to Interface the MAX30101WING Pulse Oximeter with the MAX32630FTHR


要約: This quick start guide explains how to interface the MAX30101WING with the MAX32630FTHR to run an example program.

Introduction

The MAX30101WING is a rapid development prototyping board designed for quick integration with other Maxim Feather and Wing evaluation boards. This quick start guide uses the MAX30101WING to configure the MAX30101 pulse oximeter in SpO2 mode. When paired with the MAX32630FTHR platform, algorithms can process the collected data to calculate heart rate and SpO2 values. The implemented algorithm is very basic and is intended for demonstrative purposes only; it is expected that users improve the example algorithm to create a more robust and accurate algorithm. Follow the below steps to set up the demonstration using the MAX30101WING_HR_SPO2 demo program.

Required Equipment

  • Computer with two USB ports
  • MAX32630FTHR microcontroller
  • Any Mbed® programmer, MAX32625PICO recommended
  • MAX30101WING pulse oximeter
  • One fine-pitch, 10-pin ribbon cable, included with the MAX32630FTHR
  • Two USB cables to connect the MAX32625PICO and MAX32630FTHR to a computer
  • Hardware Assembly

    1. Connect the MAX32625PICO to the MAX32630FTHR using the 10-pin ribbon cable used for programming and communication. The 10-pin header on the MAX32630FTHR and MAX32625PICO boards have a mating groove and can only connect in the proper orientation.
    2. Ensure jumper JP1 of the MAX30101WING is in the 1-2 position, enabling +3.3V logic.
    3. Stack the MAX30003WING on top of the MAX32630FTHR. The MAX30101WING form factor has 16 pins on one side of the board and 12 pins on the other. Make sure the 16-pin header (H1) and 12-pin header (H3) align on each board when stacking. Figure 1 shows the MAX11301WING stacking on the MAX32630FTHR.

      Stack the MAX30101WING on top of the MAX32630FTHR as shown aboveFigure 1. Stack the MAX30101WING on top of the MAX32630FTHR as shown above. Make sure to align the 16-pin and 12-pin sides of each board.

    4. Connect the MAX32625PICO and MAX32630FTHR to a PC using the USB cables.

    Software Configuration

    1. Go to https://os.mbed.com/ and log in. If you do not have an account, create one.
    2. After signing in, navigate to the MAX32630FTHR Mbed landing page by clicking the following link: https://os.mbed.com/platforms/MAX32630FTHR/. On the right-hand side, click the Add to your Mbed compiler button to add the MAX32630FTHR as a target microcontroller board to your compiler. Figure 2 highlights the Add to your Mbed compiler button with a red box on the MAX32630FTHR landing page.

      Highlights the Add to your Mbed Compiler button in a red box on the MAX32630FTHR Mbed landing pageFigure 2. Highlights the Add to your Mbed Compiler button in a red box on the MAX32630FTHR Mbed landing page.

    3. Install the Windows® OS driver for Mbed microcontrollers by scrolling down the MAX32630FTHR Mbed landing page to reach the PC Configuration section; follow the installation instructions. Figure 3 displays the PC Configuration section.

      Displays PC Configuration section of the MAX32630FTHR Mbed landing pageFigure 3. Displays PC Configuration section of the MAX32630FTHR Mbed landing page.

    4. Import the MAX30101WING_HR_SPO2 at https://os.mbed.com/teams/Maxim-Integrated/code/MAX30101WING_HR_SPO2/ into the compiler's program work space by clicking the Import to Compiler button on the right-hand side. Figure 4 highlights the import button on the MAX30101WING_HR_SPO2 repository page with a red box. This automatically opens the Mbed compiler in a new window. When this window opens, select Import to import the program.

      Highlights the Import into Compiler button with a red box on the MAX30101WING_HR_SPO2 repository.Figure 4. Highlights the Import into Compiler button with a red box on the MAX30101WING_HR_SPO2 repository.

    5. Select the MAX30101WING_HR_SPO2 program in your program work space. In the upper right corner, the target microcontroller is displayed. Confirm the MAX32630FTHR is the target microcontroller. Figure 5 highlights the location of the target microcontroller on the compiler webpage with a red box. If the MAX32630FTHR is not selected, click this area to select a target microcontroller. Once clicked, the selection window appears; select MAX32630FTHR.

      Highlights the Import into Compiler button with a red box on the MAX30101WING_HR_SPO2 repository.Figure 5. Highlights the target microcontroller selection area of the Mbed compiler window.

    6. With the MAX30101WING_HR_SPO2 program selected in the program work space, click the Compile button in the command banner at the top of the screen. Figure 6 highlights the Compile button. This initiates the download of the program's binary file.

      Highlights the Compile command button in the Mbed compiler with a red boxFigure 6. Highlights the Compile command button in the Mbed compiler with a red box.

    7. The MAX32625PICO board appears as a USB drive with the name DAPLINK in your native file navigation program. Figure 7 highlights the DAPLINK drive with a red box. Program the MAX32630FTHR by dragging the binary file onto the DAPLINK drive. Red LEDs flash on the MAX32625PICO until programming is complete. This typically takes a few seconds.

      Drag the binary file onto the DAPLINK drive to program the microcontrollerFigure 7. Drag the binary file onto the DAPLINK drive to program the microcontroller.

    8. Install the serial terminal program Tera Term by visiting this link and following the installation instructions: https://osdn.net/projects/ttssh2/releases/.
    9. Open Tera Term and select the Serial radio button and the Mbed device from the pull-down menu, as shown in Figure 8. The Mbed device could be on a different COM port than what is shown in Figure 8. Click OK.

      Tera Term opening window. Select the Serial radio button and the mbed Serial Port from the drop-down menuFigure 8. Tera Term opening window. Select the Serial radio button and the mbed Serial Port from the drop-down menu.

    10. Set the baud rate to 115200bps by navigating to Setup/Serial Port. This opens a new configuration window. Select 115200 in the Baud rate pull-down menu, as shown in Figure 9.

      Displays 115200bps baud rate selected in Tera TermFigure 9. Displays 115200bps baud rate selected in Tera Term.

    11. Hold a finger over the MAX30101 sensor and then press the reset (SW1) button on the MAX32630FTHR, as displayed in Figure 10.

      The reset button is SW1 on the MAX32630FTHRFigure 10. The reset button is SW1 on the MAX32630FTHR.

    12. Data should begin streaming to the serial terminal, as shown in Figure 11. The program collects hundreds of data points prior to calculating heart rate and SpO2, which takes a few seconds. The algorithm is very sensitive to finger moment over the sensor and can cause the algorithm to fail. For best results, minimize motion over the MAX30101.

      Figure 11. Serial terminal output for the MAX30101WING_HR_SPO2 program.

    This completes the integration and set up of the MAX30101WING with the MAX32630FTHR. Please continue to use this quick start as an example for making your own applications using the MAX30101 pulse oximeter. Maxim has several Wing evaluation boards to enable rapid development of entire systems. Check out Maxim's Feather and Wing solutions for your next project!

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