#SecondLichuangContest# Determined to innovate - electronic building blocks

## **1. Introduction to the work**

There are some electronic building blocks on the market, but apart from the ultra-low-end and high-end ones, there are obvious gaps in the middle. This design aims to design the rules, interfaces, electrical and mechanical dimensions of electronic building blocks, etc., to provide broad space for later expansion.
The electronic building blocks use a 10x10cm base plate, with a nine-square grid on the base plate, and the modules are arranged according to the size of 3x3cm; the modules are planned to be connected using 2.54mm pin headers and female headers; there are 2.54mm jumpers on the power, ground, and functional ends of the modules for quick connection. The base plate has a bus that can be quickly connected, or it can be connected with a 2.54mm Dupont line; for modules exceeding 3x3cm, it can occupy various positions such as 1x2, 2x2, 1x3, 2x3, etc.; the base plate can also roll out a large 10x20cm base plate, but the interface of the module is generic.
For electronics beginners to intermediate electronics enthusiasts, the advantage of this electronic building block is that it does not lose the flexibility of the perforated board, and does not need to start from scratch every time to lay out the perfboard, various CPU, power supply, display, interface, simulation circuits, all modules are available. Intermediate electronics enthusiasts can use this as the basis for a principle prototype to splice their own electronic equipment. Beginners can learn electronic technology in modules and units, which reduces failures caused by beginners' poor grasp of welding and also reduces the difficulty of designing all sub-modules at once.
This design is suitable for the development and growth of Lichuang platform, and all parties including PCB, components, suppliers and users will benefit. There is no copyright reserved for this design. It is recommended that Lichuang take over and retain the trademark, copyright and commercial rights of this design. As a university teacher who has been working in electronics for 20 years, I hope to see a win-win development direction and practical results for all parties.

For example, it can include but is not limited to the following:
1. Pictures of the overall appearance of the work or pictures of the welded and assembled PCBA;
after several modifications and adjustments, a V1.0 version has been produced. Although it is not perfect, it should be able to be used first. Used it.
Below are some design drawings. The order has been placed for panel making. At the same time, in accordance with the requirements of the competition, an STM8 microcontroller was purchased to build the circuit board for the competition.
Figure 1, the small base plate (front) of the electronic building blocks:
 
Figure 2, the small base plate of the electronic building blocks Medium base plate (reverse side):
 
Figure 3, Medium base plate (front side) of electronic building blocks:
* * **
Figure 4, the building board of the electronic building block (the front side has been processed, and the later stage is It can be cut into pieces for use. Special note: The STM8 experimental board refers to the design of the mall’s open source board, thank you!):
 
Figure 5, the building board of the electronic building block (reverse side, has been processed):
 
Figure 6, the building board of the electronic building block (for inspiration of usage, not yet processed):
 
2. The research background, purpose and function of the work, and market application prospects;
    there are some electronic building blocks on the market, but apart from ultra-low-end and high-end ones, there are obvious gaps in the middle. This design aims to design the rules, interfaces, electrical and mechanical dimensions of electronic building blocks, etc., to provide a broad space for later expansion.
The electronic building blocks use a 10x10cm base plate, with a nine-square grid on the base plate, and the modules are arranged according to the size of 3x3cm; the modules are planned to be connected using 2.54mm pin headers and female headers; there are 2.54mm jumpers on the power, ground, and functional ends of the modules for quick connection. The base plate has a bus that can be quickly connected, or it can be connected with a 2.54mm Dupont line; for modules exceeding 3x3cm, it can occupy various positions such as 1x2, 2x2, 1x3, 2x3, etc.; the base plate can also roll out a large 10x20cm base plate, but the interface of the module is generic.
    For electronics beginners to intermediate electronics enthusiasts, the advantage of this electronic building block is that it does not lose the flexibility of the perforated board, and does not need to start from scratch every time to lay out the perfboard, various CPU, power supply, display, interface, simulation circuits, all modules are available. Intermediate electronics enthusiasts can use this as the basis for a principle prototype to splice their own electronic equipment. Beginners can learn electronic technology in modules and units, which reduces failures caused by beginners' poor grasp of welding and also reduces the difficulty of designing all sub-modules at once.
    This design is suitable for the development and growth of Lichuang platform, and all parties including PCB, components, suppliers and users will benefit. There is no copyright reserved for this design. It is recommended that Lichuang take over and retain the trademark, copyright and commercial rights of this design. As a university teacher who has been working in electronics for 20 years, I hope to see a win-win development direction and practical results for all parties.
3. What are the highlights of the work in terms of innovation, interest, practicality and even public welfare?
    Let’s summarize several features of this design:
1. Convenience: All holes on the bottom plate are arranged at a pitch of 2.54, which can be easily connected to universal boards, expansion modules, and interface boards currently on the market. It can be used as the most basic universal board. Board to start. Nowadays, the pace of electronic design is relatively fast. It is very efficient and convenient to pick up a board and run the basic parts in 15 minutes.
2. Scalability: This baseboard is designed according to the current mainstream circuit module or chip size. After research and analysis, a 2.54-spacing pin header and a female header are used, and a single unit is arranged with 44 pins (holes). At the same time, various expansion modules such as 1X2 and 2X2 can be expanded. Several modules have been made so far, such as driver module, operational amplifier module, DC-DC module, FT232 USB interface module, etc. There is no limit to expansion. In the dream, all the packages in the Lichuang Mall can be combined into a modular building board. For rapid verification, you can buy chips and add a building board to quickly carry out testing.
3. Practicality: For beginners, this electronic building block can be a stepping stone to explore and research electronic technology. For electronic veterans, it is the key to quickly start experimental circuits. Based on my own experience, when starting a new project, I always have to piece together resources from various previous boards and modules, connect and test the circuit parts that I am not sure about, and then design the first version of the circuit. motherboard. So this design is very practical.
4. Public welfare: The development of Lichuang Mall is full of public welfare elements. For example, the mall has complete information on components and a relatively complete packaging library. It would be ideal if common chips could have a building board with optional electronic building blocks. All the results of this project are hoped to be transferred to Lichuang and developed under Lichuang's platform. At the same time, we hope that people with insight can join this project so that this project can continue to improve its level and is suitable for most electronic engineers and hobbies. or use.
5. Fun: I hope everyone can play with this electronic building block together, give full play to everyone's strengths, and make their own maturely applied circuit modules into part of the building block. This is very interesting and will allow more players to enjoy it!

## **2. System Architecture Diagram**

Use the form of flow chart or mind map to describe the structure of your work, that is, the scheme diagram.
The structure of this work is very simple. It is an electronic building block that is easy to use and has flexible functions. Lichuang Mall can serve as an organizer and manager, allowing building block modules to be circulated, continuously upgraded, and playability improved.

## **3. Description of the hardware part**

1. Attach a picture or source file of the schematic & PCB physical diagram (the official recommendation is that you try to upload the source file). If it is a picture, please ensure that the picture is clear and legible;
2. Use words to briefly explain the implementation principle of the work and the working process of the system.
    We also took many detours during the design process, and finally found that it is most convenient to leave the greatest initiative to the users. The main design highlight is that there are three circles of copper foil at the bottom that can be overlapped and welded. According to needs, a certain pin of the building block module can be connected to the three circles of copper foil bus through a resistor, capacitor or inductor. Those close to the pads can be directly connected with solder. For the inner ring bus, it is recommended to use a 1206 resistor or other device for overlapping, such as a 1206 0R resistor, or a pull-up or pull-down resistor. For simple circuits, a 2-turn bus may be enough. For complex dual power modules, all 3 turns of the bus can be used.
    The figure below briefly explains the lap welding method:
    the red one can be a 0603 0R resistor to lap weld to the surrounding copper foil, or it can be a decoupling capacitor. For the copper foil of the inner ring, shown in the blue box, you can use a 1206 0R resistor to overlap, which is convenient and quick. After a circle of circuit connections is satisfactory, the three terminals in the middle can be used to connect the power supply. At this time, the module is inserted into the building block base plate and the test can be quickly started.
 

## **4. Material list (BOM list)**

List the materials used for this work Get the main components (key components are enough), such as microcontrollers & ARM chips, application-specific integrated chips (ASICs), sensors, functional modules, etc.
If the chip listed is from our Lichuang Mall, it is best to write down the product number of the device or attach the corresponding purchase link. Since it is an electronic building block, various chips and components from Lichuang Mall can be used in this building block to make corresponding test modules or functional modules.

## **5. Description of the software part**

If your work involves software, please list the software workflow diagram corresponding to the work, as well as the routines and source code of the key parts (if you want to open source, please upload all the source code) .
    Electronic building blocks do not contain software for the time being. The so-called design thinking in the development process may be regarded as "software".

## **6. Demonstration of the work**

At present, the PCB has been manufactured. After receiving it, you can weld, debug, and upload the demonstration of the work.
    I received the PCB and soldered a preliminary sample for everyone to see: [https://v.qq.com/x/page/f0540rg5lf2.html](https://v.qq.com/x/page/f0540rg5lf2. html)

## **7. Summary**

For example, some of your experiences in completing the work, technical problems or debugging experience, future plans for the work, and suggestions and opinions for our organizer, etc.
This work is thanks to the communication platform provided by Lichuang. If conditions permit, I hope that the results and design copyright of this project will be transferred to Lichuang as an open source project for the community or mall. Benefit all Lichuang users.
Many types of chip verification boards can also use this solution to make rapid prototype verification boards, which can save a lot of time in dealing with peripheral circuits.