ESP32: maxing out number of connected/mixed devices/sensors/displays/etc aka available pins a good idea?

Hey everyone,

in short: is there a “best practice” around how many (different) physical devices/sensors/displays/etc can be connected to an ESP32 without creating issues?

Context: in my hallway I’m currently running 2 esphome nodes, both on devkit V1 boards.

Node 1: sender and receiver for 433mhz remote control. Just a small black box with a usb cable for power.
Node 2: “weather station” which displays current weather, forecast and indoor “weather” data on an epaper display. Physically connected: waveshare epaper display, 5 push buttons, DHT22 for temperature/humidity, mh-z19c co2 sensor, and a 3-LED neopixel module for notifications. Beyond that in software: pulling data from the main HA instance for forecast data and other sensors around the house.

I’m now working on adding power and gas consumption monitoring, so another 2 TCRT5000 modules need a “home” (aka: input pins and the code and logic to go with).

Option 1: add them to the 433mhz hub which is too “big” for it’s current usecase anyway
Option 2: a dedicated additional esp8266 for the 2 TCRT modules
Option 3: find another 2 input pins on the weather station node and add the TRCT modules there.

Of course I would have to make sure that the power source is big enough, but that taken aside: is there a limit of what “should” be connected to a single ESP32 as long as pins are available and the wall plug is big enough? Are there certain devices that shouldnt run on the same board as they interfere with eachother?
After adding the CO2 sensor and the DHT22 to the weather station node I occasionally had issues with refreshs of the epaper display, it sometimes just got “stuck” in either the “all black” or “all white” screen of the refresh process, without any log entries, and the underlaying ESP just kept going.

No YAML code yet, as I would like to figure out the physical setup first.

Thanks a lot in advance! Cheers :slight_smile:

Other than the GPIO pins you have to be careful with the state of during boot the only practical limitation is the current available from the 3.3V regulator on your chosen board.

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Thanks a lot, then I’ll go from there :slight_smile: