ESP32 1Wire Pins

Other Hardware Sensors
1

What Pins on the ESP32 can I use for 1Wire Data ?
I cant use any ADC2 Pins because I want to use WiFi while reading my DS18B20 sensors.
I need 4 Pins, because I want to build 4 independent 1Wire networks.
GPIO32 and 33 should work, but I am not sure if for example GPIO 34 and 35 would work too because thy are labled as input only.
Has someone ever tried this ?
Thanks!

2

There are 1-WireTM Master (driver) chips that connect to the host microcontroller via I2C or UART ...

3

I Have a total of 120m cable with all sensors combined. That could be too much even for these drivers. I think the safer way is to build multiple networks on different Pins

4

Maybe you can create 4x software 1-wire using the OneWire library.
Something like that:

#include <OneWire.h>
#include <DallasTemperature.h>

OneWire wire1(GPIO_36);
OneWire wire2(GPIO_39);
OneWire wire3(GPIO_34);
OneWire wire4(GPIO_35);

DallasTemperature sensor1(&wire1);
DallasTemperature sensor2(&wire2);
DallasTemperature sensor3(&wire3);
DallasTemperature sensor4(&wire4);

void setup() {
    sensor1.begin();
    sensor2.begin();
    sensor3.begin();
    sensor4.begin();
}
5

Yes I want to do it that way. But will it work on the Pins you used ?

6

In that case you probably need the active drive as on those driver chips - rather than the simple port pin drive.

You could still have multiple 1-WireTM networks by using multiple driver chips...

See also:

They speak of "weights" (ie, total length of wires) up to 200m with DS2480B-type drivers

7

I haven't read the esp-32 doc so I can't tell for sure. Usually GPIOs work fine for about anything.
However, @awneil has a good point. It's possible you won't be able to reach that far.
You should test with one sensor over the long distance and see if you can communicate without a driver chip first.

8

Can you give me any information on how to use such a master like the ds2480b ?
I cant find any librarys or anything else :frowning:

9

Then you'll have to work from the datasheets.

Again, might be worth asking in the AD forums ...

10

All GPIO line work as IO pins execpt 34, 35, 36, and 39 of the following 30-pin ESP32 Classic Dev Board.

ESP32PinSignalX
ESP32PinSignalX1056×581 80.3 KB

11

How did I manage to screw that so hard! :grimacing: