Pulse Oximeter and Heart Rate Sensor - MAX30101 & MAX32664

Sensors Biometrics
1

Hi

when I run the code for the mention sensor, I get: “Could not communicate with the sensor!!!”

the hardware is a Teensy 3.2 using I2C bus 0 (pots 18 and 19)

I know the i2c port works because I can talk to a BME280

using a I2C master (Total Phase Aardvark) with i2c address of 0x57 (7 bit) or 0xAF (read address) I receive a no ack on the 9th clock.

SEN-15219

any thoughts?

thanks,

Richard

2

Hi Richard,

It sounds like there is probably a hardware issue going on here. Are you making sure to connect the RESET and MFIO pins along with your I2C connections? Also, to make sure there are no connection issues, can you please take a few photos of your sensor breakout and the circuit you have it in with your Teensy and attach them to your reply? Please do your best to make sure they are clear and well-lit.

3

thanks for the rely

here are some photo, the address is actually 0x55 (for the MAX32664), I can see reset toggle (1 to 0 then to 1) and MFIO is 1.8V as that’s the pad IO voltage for the MAX device

finally got my attachments to attach

thanks for your help

Richard

IMG_7502.jpg

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IMG_7501.jpg
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4

Hi again Richard,

Thanks for taking those photos. They are very helpful. Just to confirm, you are able to see the MAX32664 on the I2C bus at 0x55? If that is the case, I think it might be a compatibility issue with the SparkFun library and the Teensy since you are getting the “255” error. If that is the case, I will try and test to see if I can identify what the issue here is and hopefully, we can find a fix.

5

thanks Mark for your time on this.

The scope photo shows that there is a no-ack on the 9 th clock. The address looks ok, but the MAX32664 does not respond.

6

Hi Richard,

I just finished testing the Pulse Ox breakout on a Teensy 3.6 and it works just fine so there are no problems with the library. I’m not familiar with the shield you are using so I’m curious if that is causing some of the weird behavior. Are you able to connect the sensor directly to your Teensy by chance? Also, what pins are you using for MFIO and RESET?

7

thanks Mark

I’m using a Teensy 3.2 (s/b the same as the 3.6). I’ll try a direct hook up. RST is on port 21 and MFIO is on port 7. I did a custom shield, looks like this:

PCB.jpg
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schematic.jpg
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8

thanks Mark, yes, confirmed it works with a T4.0 break out. Thanks for your assistance with this.

Richard

9

Awesome! We’re always happy to help as much as we can! Let us know if you run into any other issues with these or have any questiosn about this other SparkFun products.

Happy Hacking!