Solved the problem, I did two things wrong:
Evok output:
1Wire Sensors/Devices
Sensor DS18B20 - 28FF896672150104: 19.1°C
Sensor DS18B20 - 28FF1FDF7215012D: 20.1°C
Sensor DS18B20 - 28FF71B761150300: 39.5°C
Sensor DS18B20 - 28FF147F611502B8: 37.9°C
Sensor DS18B20 - 28FFFEA162150371: 20.6°C
Sensor DS18B20 - 28FF55B66215038C: 45.6°C
I am not able to connect any number of DS18B20-sensors (single one straight to the port or through the 1wire 8port hub).
I'm using the pinout as described on: https://www.unipi.technology/tutorial/topology-of-1-wire-network-46
It seems strange to me that even with nothing connected i see the below:
pi@unipi:/sys/bus/w1/devices $ ls
00-7a0000000000 00-ba0000000000 w1_bus_master1
The seem to be dummy devices as their id's change over time, both of them missing the w1_slave-file
it makes me think that I'm missing a configuration step, i am however unable to find any notion what i need to configure.
The UniPi M20x is corrently running Rasbian Stretch with Evok (https://github.com/UniPiTechnology/evok#testing-latest-git-versions)
Evok lists 1wire as empty but this might be because i have not configured it properly:
#!! don't use # for inline comments
[MAIN]
log_level = ERROR ; one of INFO, DEBUG, WARNING, ERROR, CRITICAL
log_file = /var/log/evok.log
webname = unipi-neuron
staticfiles = /var/www/evok
;password =
;rpcpassword =
secret =
port = 80
enable_cors = False
cors_domains = *
modbus_port = 0
#modbus_address = 127.0.0.1
modbus_address = *
[NEURON_1]
scan_frequency = 2
scan_enabled = True
[OWBUS_1]
owbus = --i2c=/dev/i2c-1:ALL ; scanned bus (--i2c=/dev/i2c-1:ALL or localhost:2122 or 'u' for USB dongle)
interval = 3 ; [s] default sensor reading
scan_interval = 300 ; [s] how often is made searching
How did you, friendly forum member, get 1wire to work?
Thank you for your reply, just a clarification on:
"You should be able to implement the solution using NodeRed if it is possible for Nodered to open linux serial line to access Modbus RTU."
This went over my head, can you elaborate a bit more? Essentially id like to use something like node-red-contrib-modbus. Will I not be able to do that? I'm aware it might come out a bit naive and it's simply not that easy.
To read out a value from the PLC to the UniPi over Modbus RTU, will I only need a UniPi with NodeRed (+flow) on top or is there more to it? Example I might look at for reading values over Modbus RTU?
I was thinking of using the Neuron M203 as a POC and move over to the Neuron 500 series as the pilot hardware. I assume the Neuron M203 supports both Modbus RTU & TCP? Otherwise i need to hurry and cancel my order of the M203 :)
I have a proof of concept project in mind for a potential client within the brewery industry.
Fist here's a simple context diagram of what I'd like to achieve:
Image link: https://pasteboard.co/GDoCYPq.png
background
The client has two air compressors running to supply compressed air for manufacturing PET-bottles. Once created/blown up, they are cleaned (more air used), filled (water, soda,beer), packed and shipped. In summary, it's pretty important that these machines are running 24/7. Each machine is controlled by a PLC, that ensures the physical they run correctly by reading inputs (temp, pressure) and monitoring these values against treashold values that must not be breached or the PLC shuts down the machine.
Use case
Read out the PLC process data over modbus every Xs and send it to a remote micro service (mqtt/Jason). Display the data on a dashboard in near real-time for remote readout. Monitor data against the same treasholds, alert the operations of a potential failure before the machine is shut down.
I am confident on the software side of things, hardware/modbus not so much...
To my eyes the unipi looks like it can fulfill all of the above, am I wrong?
Would I need a unipi per PLC or can I read more than one with a the single rs485/modbus connection?
Can I read the data of the PLC using nodered (nodered supports modbus) or will I need something more?