#9th LCSC Electronics Contest# Temperature and Humidity Detector

* 1. Project Function Introduction
1. Accurately, promptly, and without error measures the temperature and humidity of the current environment.
2. Clearly displays the current temperature and humidity values ​​using two three-digit LED displays. 3.
Compact, exquisite, and aesthetically pleasing design, suitable for placement on desks and other desktops.
4. Uses common AAA batteries as a stable, reliable, and continuous power source.
5. Has a wide measurement range, capable of measuring temperatures from -40°C to 125°C and relative humidity from 0 to 100%.
The Little Cow temperature and humidity sensor can be used as a desktop ornament and can also measure the current ambient temperature and humidity.
*2. Project Attributes
: LCSC Summer Training Camp
*3. Open Source License:
GPL3.0
*4. Hardware
: Powered by two AAA batteries; CR2032 is reserved because the design uses a digital tube display, and we wanted to test whether the CR2032 can handle it. The sensor uses a 3V power supply and two 4.7K pull-up resistors.
STM32G030K6T6 microcontroller minimum system circuit includes power supply, crystal oscillator, reset, and download circuits.
 
SN74HC595PWR decoder is used. Two three-digit common cathode digital tubes are used, one to display temperature and one to display humidity.
LEDs for testing and a wake-up button are added.
1. Membrane: https://dos.szlcsc.com/home.html
2. Outer Shell (Select 3D Printing in JLCPCB Order Assistant)
 
Step 1:
Soldering the Circuit Board
1. Soldering the STH40 Sensor: First apply solder paste, place the sensor on the solder paste-covered area, and use a hot air gun to heat it.
2. Soldering can be done with a soldering iron during the rest of the process.
Note: Solder the SN74HC595PWR first, then solder the digital tube.
Step 2:
Downloading the Program:
Open the source program and connect the SWCLK, SWDIO, GND, and 3.3V in ST-LINK to the corresponding circuit boards. After successful download, power on again.
Note: Remember to install the ST-LINK driver.
Step 3:
Place the circuit board into the outer shell and tighten the (M3*6) screws as shown in the picture below.
Step 4:
Cover the back cover and tighten the (M3*12) self-tapping screws. Finally, apply the film as shown in the picture below.
You can print various different colors for replication.
*5. Software Part
Training Camp Code
*6. BOM List
Assembly BOM


Item
No. Name
Remarks


1.
Little Bull Outer Shell Top Cover
 


2.
Little Bull Outer Shell Bottom Cover
 


3.
Film
 


4.
M3*6 Screws
Tighten Circuit Board


5
M3*12 self-tapping
screw casing



(see attachment
7), competition logo verification
 
, and demonstration of your project (record as a video and upload).