Issue with Configuring MAX30101 with nRF Connect SDK

[Jack Alex]

Hi, all,

I am new to nRF Connect SDK and am currently facing some configuration issues with the MAX30101 driver in a Zephyr project. Here is the example program and source code for the driver. My main question is: how do you configure sensors like the MAX30101 without directly editing the auto-generated .config file?

I successfully got the example code to work on the nRF52 DK using nRF Connect SDK v2.5.2, but it only retrieves readings from the green LED. I would like to get readings from the red and IR LEDs as well. The Kconfig file in the source code shows different configuration options for the sensor, but when I try to open the Kconfig GUI in VS Code, the section for the MAX30101 is blacked out. It states that I haven't set DT_HAS_MAXIM_MAX30101_ENABLED to y. However, when I check the auto-generated .config file in the output, I can see that DT_HAS_MAXIM_MAX30101_ENABLED=y is already set.

After some trial and error, I discovered that it is possible to directly edit the .config file to configure the MAX30101, and I was able to turn on the red and IR LEDs and obtain some readings. However, this approach is quite cumbersome since the .config file is re-generated every time I modify the prj.conf file in my project. I'm wondering if there is a way to configure the MAX30101 so that the settings are automatically registered in the .config file without manual editing.

Thank you in advance

Jack

[Hung Bui]

Hi Jack, 
Could you show your device tree board configuration  ? 

If you set a node with compatible = "maxim,max30101" then DT_HAS_MAXIM_MAX30101_ENABLED  will be set. 

Have you tried to set CONFIG_MAX30101_LED2_PA=0x33 in your prj.conf ? 
Editing the .config file directly is not the best way to do configuration. 

[Jack Alex]

Hi, Hung,

Thanks for the reply. Here is the device tree overlay.

// To get started, press Ctrl+Space to bring up the completion menu and view the available nodes.

// You can also use the buttons in the sidebar to perform actions on nodes.
// Actions currently available include:

// * Enabling / disabling the node
// * Adding the bus to a bus
// * Removing the node
// * Connecting ADC channels

// For more help, browse the DeviceTree documentation at https://docs.zephyrproject.org/latest/guides/dts/index.html
// You can also visit the nRF DeviceTree extension documentation at https://docs.nordicsemi.com/bundle/nrf-connect-vscode/page/guides/ncs_configure_app.html#devicetree-support-in-the-extension
&i2c0 {  
    max30101: max30101@57{
        status = "okay";
        compatible = "maxim,max30101";
        reg = < 0x57 >;
    };
};

&gpio0 {
	status = "okay";
};

When I attempt to set any MAX30101-related configuration, I receive a warning message. Interestingly, despite the warning, I still see the configuration changes from prj.conf reflected in the .config file.

[Hung Bui]

Hi Jack, 

Could you confirm that you now can build and don't have to change .config manually ? 

Sometimes VSCode couldn't get all the configurations correctly and will show some warning. But if you can build with no problem then it's fine. You may want to try remove the build configuration and build again with VSCode. 

[Jack Alex]

Yes, I do see the .config change by changing the prj.conf file in my project. 

Is there any way that I can use the GUI to configure it?

[Hung Bui]

Hi Jack, 
I would suggest to use prj.conf directly. It's the easiest way. 
Otherwise if you want to use GUI, you can use the nRF Kconfig GUI 

Then you can click save minimal and save it as a .conf overlay file. Make sure to use this overlay file in your project.