SHT31 Review + First Prototyping Expansion Board

hujj

SHT31 Review + First Prototyping Expansion Board [Copy link]

 

In order to further develop the functions of SHT31, we plan to lead out signal lines such as SWDIO, SWDCLK, TX, RX, SCL and SDA through the expansion board. It took several days to draw the expansion board. After the proof came back, we couldn't wait to start making it. The following is the expansion board that came back with the proof:

The expansion board also reserves a position for lithium batteries, ready to use the original mobile phone lithium batteries to provide more sufficient power. With lithium batteries, the charging control module must also be considered. The expansion board also has a microUSB interface to charge via a USB data cable. The expansion board also reserves a position for the TTF to USB chip CH340 for serial communication. After soldering the CH340 chip and peripheral components, SHT31 can communicate with the computer through the expansion board.

The lithium battery and SHT31 evaluation board are fixed to the expansion board through spring clips. The following is the process of making the spring clips:

Cutting and making spring card:

Use needle-nosed pliers to bend the spring clip:

Use the spring sheet in the row seat as the signal contact spring sheet:

Fix the SHT31 evaluation board and the expansion board:

Several problems were found during the first production. First, the material of the spring card was too hard, which made installation and removal inconvenient. Second, the material of the signal contact spring was also too hard, and the contact was unreliable. Finally, the measurement was inaccurate, and the contact position was a little off, so I had to modify the PCB wiring and re-order the sample.


This content was originally created by EEWORLD forum user hujj . If you need to reprint or use it for commercial purposes, you must obtain the author's consent and indicate the source

littleshrimp

This is equivalent to making your own download fixture.

hujj

littleshrimp posted on 2020-1-3 23:38 This is equivalent to making your own download fixture

Yes, I am going to try to download it using ST_LINK, but I wonder if it will work.

hujj

littleshrimp posted on 2020-1-3 23:38 This is equivalent to making your own download fixture

This is to prepare for downloading and burning codes, and by the way, the serial port and I2C signal lines are also brought out to expand its functions.