How many 1-wire devies can I connect to one 1-wire interface board?
(I have 5 x DS18B20's and a ibutton reader im hoping to connect.)
Can I add a ADC and IO board to the same pi3+ as the 1-wire board or would it cause problems?
I will be using this to add inputs and outputs to Home Assistant running on a NUC, how would the raspberry pi comunicate with the NUC? Im asuming through the LAN if thats possiable.
Kind regards
Information on 1-wire please
1307 Views - Created 16/04/2020
16/04/2020
Posted by:
jdenver
16/04/2020
Posted by:
andrew
Location:
United Kingdom
Hello
The maximum number of devices you can connect to a 1-wire bus is dependent on several factors such as cable length and outside interference but there shouldn't be any problems with using 6 devices on a bus.
Maxim has a good tutorial on their website on building reliable 1-wire networks, you can find it at https://pdfserv.maximintegrated.com/en/an/AN148.pdf
You can connect the ADC Pi, IO Pi and 1-Wire Pi to the same Raspberry Pi. I would recommend stacking the 1-Wire Pi on top of the other two as the RJ12 socket on the 1-Wire Pi is the same height as the mounting kits so it can be a tight fit with other boards stacked on top.
You should be able to send the data from the inputs and outputs on a Raspberry Pi to Home Assistant on a NUC over the LAN. One method would be to use an MQTT broker such as Mosquitto on the NUC to act as a message store. The Raspberry Pi can then publish MQTT messages to the broker each time an input or output changes and Home Assistant can subscribe to the MQTT broker which would notify Home Assistant when a new message arrives.
The maximum number of devices you can connect to a 1-wire bus is dependent on several factors such as cable length and outside interference but there shouldn't be any problems with using 6 devices on a bus.
Maxim has a good tutorial on their website on building reliable 1-wire networks, you can find it at https://pdfserv.maximintegrated.com/en/an/AN148.pdf
You can connect the ADC Pi, IO Pi and 1-Wire Pi to the same Raspberry Pi. I would recommend stacking the 1-Wire Pi on top of the other two as the RJ12 socket on the 1-Wire Pi is the same height as the mounting kits so it can be a tight fit with other boards stacked on top.
You should be able to send the data from the inputs and outputs on a Raspberry Pi to Home Assistant on a NUC over the LAN. One method would be to use an MQTT broker such as Mosquitto on the NUC to act as a message store. The Raspberry Pi can then publish MQTT messages to the broker each time an input or output changes and Home Assistant can subscribe to the MQTT broker which would notify Home Assistant when a new message arrives.
16/04/2020
Posted by:
jdenver
Thank you for the links
Quote from andrew
One method would be to use an MQTT broker such as Mosquitto on the NUC to act as a message store. The Raspberry Pi can then publish MQTT messages to the broker each time an input or output changes and Home Assistant can subscribe to the MQTT broker which would notify Home Assistant when a new message arrives.
Are there any other methods? Ive have used MQTT before but was wondering what else was out there for connectiverty.
Thank you, Regards.
Quote from andrew
One method would be to use an MQTT broker such as Mosquitto on the NUC to act as a message store. The Raspberry Pi can then publish MQTT messages to the broker each time an input or output changes and Home Assistant can subscribe to the MQTT broker which would notify Home Assistant when a new message arrives.
Are there any other methods? Ive have used MQTT before but was wondering what else was out there for connectiverty.
Thank you, Regards.
16/04/2020
Posted by:
andrew
Location:
United Kingdom
I don't have a lot of experience with Home Assistant so I am not sure what other methods of communication it supports. The only method I have used is MQTT.
The Home Assistant forum may have more information on how to communicate between a Raspberry Pi and Home Assistant.
The Home Assistant forum may have more information on how to communicate between a Raspberry Pi and Home Assistant.
20/04/2020
Posted by:
jdenver
Will your 1-wire board support parasite powered 1-wire devices?
20/04/2020
Posted by:
andrew
Location:
United Kingdom
I have tested our 1 Wire Pi Plus and Zero boards with the DS18B20 temperature sensors and several iButton devices using parasitic power and they do work.
If you have several devices connected over a long 1-Wire bus then I would recommend using powered 1-wire devices as you may find that the voltage drop on the bus makes parasitic devices unreliable.
If you have several devices connected over a long 1-Wire bus then I would recommend using powered 1-wire devices as you may find that the voltage drop on the bus makes parasitic devices unreliable.
20/04/2020
Posted by:
jdenver
Thank you, just ordered a board #13580 so looking forward to trying it out.
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