Get Spo2 Assistant to connect to a CMS50F Pulse Oximeter running on a Silicon Mac

[darral.freund]

If anyone wants to know how to connect a Contec CMS50F pulse oximeter to a silicon Mac in Parallels running Windows 11, this is how I did it.

I got a new 16” MacBook Pro M2 (Ventura 13.2.1), and wanted to get my CMS50F pulse oximeter connected to a Windows 11 VM running on Parallels.  I was able to get it to work with Oscar without issues, but also wanted the VM option.


After a lot of unsuccessful attempts, I was finally able to get the Spo2 Assistant (v 3.0.4) to run and connect to my pulse oximeter on the Windows 11 ARM VM (that I downloaded from Parallels).

The key is that the CP2102 USB to UART Bridge Controller driver installed by the Spo2 Assistant doesn’t work.  It didn’t work with the newer version 3.1.0.2 either.

I was able to find a driver that works from the chip manufacturer at:

https://www.silabs.com/documents/public/...Driver.zip

Here is the list of possible drivers, but the above url should download the correct zip file:

https://www.silabs.com/developers/usb-to...=downloads

Download the driver and unzip the folder of drivers.  I did this part on the native Mac.


The pulse oximeter needed to be connected for the following to work:

In Windows 11, select Run, and then type devmgmt.msc

That brings up the Device Manager.  Under Ports (COM and LPT), it should list the controller:

In my case it was a CP2102 USB to UART Bridge Controller.  If yours is different from a CP210x controller, this probably won’t work.  

After installing the Spo2 Assistant software and selecting to install the driver during installation, there was a question mark by this device and a note that the driver didn’t install.

I selected the device, right clicked, and select update driver.  Next I navigated to the top level of the downloaded driver folder and selected the .inf file.

For me the correct driver was selected and installed.  I was then able to connect to my pulse oximeter using the Spo2 Assistant.

[pholynyk]

Thank you for the detailed instructions.

I will note that the CPT2102 bridge chip was used in the version 1 CMS50F. The version 2 hardware uses a different interface chip.

[dgconder]

Contact CMS sensor UART issues
This seemed like the most logical place to post my experience. I am running OSCAR in a Windows 11 in a VM on a silicon MAC book pro M1 
I was able to get the silicon labs drivers installed. Using SP assistant I was able to import data from two different content sensors the CMS50D+ and the CMS50D-BT
Then all of a sudden I started having issues with the 50 D+ It would say that the device stoped responding after about 90% upload. I fiddled with VM settings I even went and installed the Silicon labs driver on the MAC side. I never did get it working. I have to take this device to a native windows machine to pull the data then "sneakernet" it over to to my machine via thumb drive. It may have had something to do with the latest MAC OS Sequoia 15.2. 

I was primarily on Windows because SPO2 did not have an app for MAC that I could see. Otherwise I would probably be running OSCAR natively on MAC. 

If anyone has any bright ideas on taking a symbolic "whacking hammer" to fix this issue I would be curious. For now I am moving away from this sensor.