Esphome ds18b20 no sensors found after 8 sensors

ESPHome
1

I’m trying to make a nodemcu board with 20 ds18b20 sensors. The sensors are connected to 5V via VIN, the data is connected to D1. I installed a 4.7K pullup between vin and D1. The remaining pin is connected to GND.

Everything works fine, until I add more than 8 sensors. It does not matter which ninth sensor I add, after sensor 8 I get this message on startup:

[dallas.sensor:077]: Found no sensors!

I’ve tried using the 3.3V, but then it stops working already after 6 sensors. I’ve switched from a 1A power supply to 1.5A, but this doesn’t make any difference.

The sensors I use are the waterproof ds18b20 variant with 1 meter cable per sensor. The sensors are connected in a star pattern.

Any hints, or am I running into the limits?

2

Not using ESPHome but Tasmota on ESP8266 has 8 1-wire sensor limit :frowning:
Guess this is buried somewhere in used libraries :slight_smile:
Best, JR

3

Some people here seem to have the same issues with multiple sensors

4

Seems I made a stupid mistake, checked the color code of my pullup resistor, it’s 47K instead 4.7K :slight_smile:

Now it finds 10. Will experiment a bit more tomorrow by adding another 10.