Hello All,
I am new to this forum.I am building a wearable project using Adafruit Huzzah ESP32 feather board, MAX30102 Heartbeat and pulse oxymetry sensor and MPU9250 IMU(alternately I have MPU6050).I have got all the components from core electronics. How do I establish the connection into a single system. Also What are the pin connection for individual sensors to ESP32? Datasheet of MAX30102 says the power option 1.8V and 3.3V(for Led),how do I powerup the device? How do I use pullup resistors for better performance? I was thinking to implement it using Arduino IDE and Blynk app via bluetooth communication however New Blynk 2.0 doesnot have Bluetooth option to choose from the list. Maximum information about this will be much appreciated.
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Hi Tara,
Welcome to the forum!!
PS: when getting some advice on specific boards a link helps a ton 
For connections to the ESP32 Feather - https://core-electronics.com.au/adafruit-huzzah32-esp32-feather-board.html
The learn guide down the bottom of the page gets you pointed to Adafruits documenation, the pinouts section specifies all of the pins used for different protocol and some options for power (A USB power bank is my personal fav).
From what I could find both the heatbeat sensor and IMU both use I2C to communicate, connecting the SDA and SCL’s (across the ESP32, and two sensors). I2C requires unique addresses from sensors or peripheral boards, in this instance its all good.
To get to your other questions:
In a majority of the boards pullup resistors will already be included, depending on how long your wires are your polling rate will be quite high, if your MPU permits it, an interupt can be set to let your MCU know when data is ready.
I dont have any expereience with Blynk, I’ve used it as an access point and connected it to a WiFi network to host a webpage to trigger some simple events in the past, there are lots of great guides around the net for getting that up and running.
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Hello Liam,
Thank you for your prompt response. I will follow your advise. I connected Max30102 and MPU6050 Vin,Gnd,SCL and SDA pins together and the Vin,Gnd,SCL and SDA pins of MPU6050 to similar pins on Adafruit Huzzah ESP32 board. I can see that MPU6050 glows it’s green LED and MAX30102 glows red. I might have made a wrong connection before. I am still confused with MAX30102 power option as it says 1.8v and 3.3v. What does this mean? Do i need separate power source of 1.8v to powerup Max30102 module or 3.3V will help. Will the board get damaged if i don’t power it appropriately?
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Hey Tara,
No worries, we’re all here to help 
Do you have a link to the modules you are using? Those voltages could be on the sensor itself or used internally, overvoltage will fry boards, some more rapid than others
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Hi Liam,
Here is the link of the module from where I purchased it:
Also, Connecting MPU9250’s Vcc,Gnd,SCL and SDA pins to same pins of Adafruit Huzzah board ESP32 feather still doesnot work. I tested with two MPU9250 module purchased from ebay. I don’t know what is wrong.
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Hey Tara,
I wont be able to vouch for those sensors as there is little to no supplied documenation.
The ESP32 Feather requires a bit of setup to get running with the Arduino IDE, all of the resources for that are in the learn guide down the bottom of the product page.
I’d get each board working in isolation first, the ESP, then get the onboard LED to flash (P13), then the sensors.
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I am getting an overall picture now. Thank you very much for helping me out.
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No worries Tara, I’m keen to see what you come up with
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