Referring to the creativity of this master, we redesigned the most amazing Qiguang board:

[Yuan Chuang | Self-made Qiguang Board (NanoLeaf) explores the implementation principle of automatic topology (Part 2) - Software Principle - Bilibili] https://b23.tv/UByE4k

Principle description

first improvement

Looking through my old circuits, you can see that I used to have a design where 5HZ would be transmitted when pressed and 1HZ would be transmitted when released.

It is equivalent to using the output resistor to simulate an analog switch, please take a closer look~~.

Then look at the circuit based on this theory.

If USB is not plugged in, the signal flows through the 1k resistor to the next WS2812.

If the next module board is inserted, the right side of the resistor will be driven by the last WS2812 on the module board, so that the odd light board module can be made at a very low cost.

For details, you can compare the solutions in the video above. Successfully replaced a microcontroller with three resistors.

The second optimization

The original uses shrapnel connectors for electrical connections. In addition to connectors, small boards need to be connected to achieve this, and the cost goes up.

I switched to USB male and female connections here, which again reduces costs and is more fool-proof.

In the original work, there is no port that can both input and output. And here I have limited the data direction to male input and female output.

I can't guard against being fooled, but I can't help it if miracles happen with great force.

It's still a long way from filling a wall. . .

The third optimization

The mechanical structure is to be modeled. . .

PCB description

If you want to mass-produce equilateral triangles, remember to make a puzzle. You have all learned the triangle area formula in elementary school.

If you don't ask for imposition, you will be at a big loss. It's obviously half the area, but they charge you double the board fee.

Program explanation

This project has not yet produced a corresponding control board, only a light board. The video below is also debugged using the development board's flying leads.

Those who are interested can develop their own control board. Driving WS2812 is very simple. Many open source projects for playing with lanterns use 2812.

Let me tell you something different. As you can see from the circuit diagram above, data from each USB port comes and goes.

In fact, through this we can make a code to detect the number of WS2812.

First, I used the MOSI of the hardware SPI to simulate the 2812 timing. Since the last 2812 data was serialized back through the USB port,

Then I can judge the number of 2812 based on how much less data is sent back, and MISO can come in handy.

See the program attachment for specific implementation.