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+Micropython project for Raspberry Pi Pico.
+Collects data from a onewire temperature sensor
+and feeds it to MQTT on a wireless connection.
+
+Before you can use it you need to:
+- connect onewire sensor to Pico,
+- set up MQTT broker on a server uneder your control,
+- optionally, but highly advisable, setup ntpd server in local network,
+- set up certificates,
+- provide settings in config.py. Skeleton in config.py.example
+
+Notes:
+
+In order to test Pico, best use Thonny.
+At the time of writing this (Jun 2024), you won't be able to see live
+interpreter in PyCharm
+Device path is /dev/ttyACM0
+To connect to it, add your user to dialout group. 
+Alternatively change permissions on that device to something like:
+chmod o+rw /dev/ttyACM0
+Or change owner on that device to your user
+
+To address pin 25 with LED use "LED":
+from machine import Pin
+led = Pin("LED", Pin.OUT)
+
+Before using tls (mosquitto, requests) you'll need to set time, for instance:
+import ntptime
+ntptime.settime()
+Be aware that default timeout on a socket there is 1 second, which may not be enough.
+I'm using usocket directly so that I can set timeout to a larger value.
+The hard part is to deal with timeout from ntp server.
+I managed to cut down timeouts drastically by running my own ntp server on local network.
+
+Another hard part is setting up certificates so that umqttsimple can use them.
+TLDR, do it like that: https://github.com/JustinS-B/Mosquitto_CA_and_Certs/blob/main/client_maker
+
+Update:
+Script from that link, now dead, provided here as client_maker.sh
+
+For background information: https://github.com/orgs/micropython/discussions/10559
+
+Script for server running MQTT reading data from MQTT and updating rrd database
+in separate project, with Bash script generating rrd database and
+generating graph from this database.
+
+Controlling temperature with PID not tested.