I have heard of various adverse cola using methods long since. One of these methods is using as the toilet cleaner. Seriously? In the holiday, our member Mr. Mi with his son Little Mi made an electronic PH test paper with micro:bit. The test paper will tell you the truth!
RGB lamp ring expansion board was made two weeks ago.
From the front of expansion board, you can see the onboard 24 RGB LEDs and microphone.
From the back, you can see a buzzer, two P1, P0 IO expansion ports and corresponding reuse selection switch.
The kit supports PH2.0 and USB external power supply.
DF always has neat tricks for connection of expansion board and micro:bit.
Micro:mate adopts flexible PogoPin.
For RGB lamp ring expansion board, the nuts are directly embedded into PCB.
Under microspur, you can see nuts are not simply welded on PCB surface but embedded in PCB. The threads run through the board. This process is unclear, not common and simple.
Insulation paper is pasted on the front.
When screwed in, screws will contact the golden finger to achieve circuit connection with expansion board accordingly.
The installation is finished hereto.
Another main component PH sensor is introduced as follows: