Bench Talk

How to Use Maxim Integrated Boards to Prototype Pulse Oximetry

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In this post, we will explain how the Maxim Integrated MAX32620FTHR and MAX30101WING enable you to prototype heart rate and blood oxygen level applications that upload sensor measurements to the Medium One IoT platform for data processing and display.

Maxim Integrated MAX32620FTHR

The MAX32620FTHR board offers a rapid development platform to help you quickly implement battery-optimized solutions using the Maxim Integrated MAX32620 Arm^® Cortex^®-M4 microcontroller (MCU) with floating-point unit. The MAX32620 MCU has 2048KB flash, 256KB SRAM, and a variety of input/output peripherals including USB, Serial Peripheral Interface (SPI), I²C, Universal Asynchronous Receiver/Transmitter (UART), 1-Wire, analog-to-digital converter (ADC), and General Purpose Input/Output (GPIO). The board features a MAX77650 power management controller and LiPo battery charger along with a MAX17055 fuel gauge for monitoring battery levels, allowing USB or battery sources to power the board. Two RGB indicator LEDs and two pushbuttons provide on-board indicators and user input.

Other sensors and I/O devices can interface with the MAX32620FTHR through expansion connectors, including Feather-compatible board headers and two 12-pin Pmod^™-compatible connectors. Mbed development tools or the Arduino IDE development environment support software development. Code libraries are available for board initialization, input/output, and a variety of processing functions to accelerate application development.

Maxim Integrated MAX101WING

The MAX101WING rapid development board features the MAX30101 optical pulse oximetry sensor. It has a Feather-compatible pinout that allows it to be directly connected to the MAX32620FTHR microcontroller board. The on-board MAX30101 sensor is a non-invasive reflective LED solution with an integrated glass cover. When combined with processing algorithms, the sensor can measure pulse rates and blood oxygen levels. The sensor features programmable sample rates and LED current for power savings. Power is controlled by the on-board MAX14750A power management chip that sets the LED drive voltage and is programmable through an I²C interface.

Medium One IoT Platform

The Medium One IoT cloud-based platform helps early-stage developers prototype their IoT project or connect their existing hardware to the cloud. It offers an IoT Data Intelligence platform enabling customers to quickly build IoT applications with less effort. Programmable workflows quickly build processing logic without requiring you to create your own complex software stack. A graphical workflow builder and run-time engine process IoT data as it arrives and route or transform it as needed for your application. Workflow library modules are available for data analytics, charting, geolocation, weather data, MQTT, SMS text messaging, and integration with Twitter, Salesforce, and Zendesk. Snippets of Python code create custom workflow modules. The web-based Workflow Studio, which provides a drag-and-drop visual programming environment, designs and builds end-to-end workflows. Workflow versioning and debugging tools support the development, test, and deployment lifecycle. The MQ Telemetry Transport (MQTT) protocol or REST APIs handle communications between IoT devices and the Medium One cloud. Configurable dashboards allow you to visualize application data and view real-time data in a variety of formats. Dashboard widgets are included for tabular data, charts, geopoint maps, gauges, and user inputs. Medium One’s iOS and Android apps build simple mobile app dashboards that can communicate with your devices through the platform.

Using Your Own MAX32620FTHR and MAX30101WING

To use your own MAX32620FTHR and MAX30101WING with the Medium One IoT Platform to measure heart rate and blood oxygen levels, check out our step-by-step article that walks you through the entire process of:

• Setting up the hardware and development tools
• Installing and running the necessary software components
• Building the code and downloading it to the board
• Configuring the board’s cloud connection parameters
• Running the board to generate real-time sensor measurements that are sent to the cloud.

Here, we also show you how to observe the published data on a real-time dashboard created in the Medium One environment. A set of next steps gives suggestions for how to extend and adapt the application for different IoT prototyping scenarios or to learn more.