1-Wire example problem

Jimis1
Posts: 35
Joined: Wed May 03, 2023 6:20 am

1-Wire example problem

Postby Jimis1 » Sun Mar 10, 2024 12:06 pm

Hi,
I'm trying to setup a DS18B20 thermometer and use the 1Wire library from here
https://github.com/espressif/esp-idf/tr ... mt/onewire

My hardware setup is with a pull-up 4k7 like it suggests and I assume it's ok. I can't read the thermometer, I get the errors
E (77649) 1-wire.device: onewire_device_iter_get_next(76): read rom_bit_complement error
E (78649) 1-wire.rmt: onewire_bus_rmt_read_bit(486): 1-wire bit receive timeout

as shown in the picture and the second picture shows the logic analyzer output. I have setup the correct GPIO pin since I get the reset pulse out. Any ideas?
Screenshot_1.jpg
Screenshot_1.jpg (281.1 KiB) Viewed 1500 times
Screenshot_2.jpg
Screenshot_2.jpg (36.96 KiB) Viewed 1500 times

MicroController
Posts: 1725
Joined: Mon Oct 17, 2022 7:38 pm
Location: Europe, Germany

Re: 1-Wire example problem

Postby MicroController » Sun Mar 10, 2024 12:37 pm

There doesn't seem to be a response to the reset ("presence pulse") from the DS18B20. Check the wiring and power supply of the sensor.

Jimis1
Posts: 35
Joined: Wed May 03, 2023 6:20 am

Re: 1-Wire example problem

Postby Jimis1 » Wed Mar 13, 2024 12:53 pm

Yeap, stupid mistake I had mistakenly soldered a 100nF in Data line instead of 33pF

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