hi everyone
Today I start my new project: A Dry Sausage DIY. To make perfect dry sausages, you have to dry them at a temperature between 11 and 15 degrees celsuis with a humidity between 75% and 80% during 4 weeks . So I decided to make my own autonom sausage-dryer with what I have on hand

To help me I used this following tutorial:

Supplies

_ drink fridge I find one on ebay for 80$
_rpi 0
_rpi 0 case
_pi-oled
_dht 22
_relay module
_humidifier
_fan (optional)

Step 1: Building

pi-oled

first thing I made is solder a new 5v pin on the pi-oled because it will take all of them when you will plug it(see on the picture)

dht 22

Place a 10k resistor between Pin 1 and Pin 2 of the DHT22
Pin 1 of the DHT22 to 3v3 on the Pi
Pin 2 of the DHT22 to GPIO24 on the Pi
Pin 4 of the DHT22 to GND on the Pi

relay module

dc+ to 5v on the pi-oled
dc- to ground on the Pi
in 1 to 20 on the Pi (humidifer)

humidifer

no 1 to dc + plug side
com 1 dc+ humidifer side

the final building part (the picture may help you more than the following text)

put the humidifer and the fan in the fridge
pass all the cable between the frigde door and the fridge (plug and dht22) I have to improve that but I don t know how yet
turn on the fan all the time, lower speed if you can choose
use the dht22 to adjust the temperature of your frigde between 10 and 15 degrees celcius

and it s done!!

Step 2: Programmation

configuration:

I use Raspberry Pi OS (32-bit) with desktop enable i2c for the screen

you have to install screen and dht22 library:

sudo apt-get install python3-pil python3-dev
sudo python3 -m pip install --upgrade pip setuptools wheel
sudo pip3 install adafruit-circuitpython-ssd1306 Adafruit_DHT

Python script

sechage.py (drying in french):

the goal is almost dht 22 give the temp and the humidity and put them on the screen
if the humidity go down to 70% the relay turn on the humidifer
if the humidity go up to 85% the relay turn off the humidifer

I use crontab to start my script on boot: