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G6EJD / ESP8266-oximetry-and-heart-rate-sensor

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4k7 resistors #1

Closed davidm-public closed 6 years ago

davidm-public commented 6 years ago

Hi, curious if you noticed any issues with the 4k7 resistors.

See comment at the bottom of this link: https://github.com/oxullo/Arduino-MAX30100

re need to resolder to Vin instead of 1.8V supply?

David

G6EJD commented 6 years ago

Hi Dave, I haven’t experienced any issues with operation of this device when using an ESP8266 or ESP32 both using 3.3v supplies and so I/O at 3.3v. The device uses a 1.8v supply so the breakout board has been designed correctly with pull-ups to 1.8v and I suspect this is an Arduino or ESP issue as 1.8v is barely enough to be registered as a high but adding pull ups to 3.3 or 5 would solve that. Needs level conversion really. The ESP32 has switchable pull-ups if that helps.