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14 Tips on Designing a PCB Programming and Testing Board

For PCB programming, I believe everyone will have many problems, and it is a very professional technique. We need a complete process to help us perform our tasks. Otherwise, you may have some severe consequences due to the wrong steps. For example, PCB cannot be used frequently and need to work again.

 

We will discuss the design process of a custom microcontroller and test board in this tutorial. The methods have been simplified for faster build and minimized error margins. By focusing on the microcontroller, you will be able to learn PCB programming without dealing with the complexity.

 

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System Design

1.System / Preliminary Design

PCB Programming the primary focus should be to understand the overall design of the board before you begin. When you know what component fits where the design process gets much more comfortable.  

The preliminary design comprises of two significant steps. First, you should build a diagram of the complete system. Treat this as your design blueprint. The blueprint will guide you on what the inputs and outputs are without going into too many details.

It is to have the idea of how the entire board functions and connects.

Printed Circuit Board with DIP Components.jpg

2.Block Diagram

A block diagram includes one block for every significant component cluster. The way these modules are linked to each other, how they interact, and how much voltage flows through each stage.

When all of these blocks add to the diagram and how much initial energy will be required, add these details to the picture. It will make your job easier by giving an idea if you will need any voltage controllers for shifting for every core block.

You need shifters for voltage control because two electrical parts are linked with each other through contributor voltage. When these two electrical parts are using different levels of energy, you need to use a shifter.

3.Select Microcontroller

You can decide what kind of microcontroller to use based on some necessary details like cost, availability, properties, etc. You can get all these details from the site of distributors.

Price over performance –Arm Cortex-M is a quality MC because of how cheap they are the level of performance you can get out of them. Even if you are PCB programming for only 8-bit, you can afford and should use a 32-bit Cortex-M.

Performance – depending on the number of GPIO pins and which uses the serial protocol.

The simplest and cheapest microcontrollers will have 32 pins with different types of features. The top of the line will have up to 216 pins; however, this might be too complex to work with if you are a beginner.

Leaded Package – This is an excellent feature because the pins of the microcontroller become readily available. The packages that come without being led have the pins tucked below the container. It means it is challenging to reach the nails if you don’t have any test points available. 

PCB Programming– Schematic Circuit Design

To begin with the connector, a regulator to control voltage, an MC chip, and a PCB programming connector.

Printed Circuit Board Schematic Diagram.jpg

4.Capacitors

To do this, we will follow these steps.

1. Begin the design by positioning a capacitor over the input pin that is on the regulator. Place another capacitor on the output pin of the regulator. The first one is for the input voltage, and the second one is for saving charge to pass it to impermanent loads. The second capacitor will also act to create stability with the regulator. Without this, the regulator will fluctuate.

2. Near the supply pins of the MC, you will place capacitors for decoupling. You can consult experts to understand what kind of capacitor to use for this function.

5.Microcontroller Pinout

Microcontroller manufacturers usually configure many different functions on the same pin to reduce the total number of required fasteners.

In the beginning, the use of the nail will start automatically. But these pins can also have alternative functions. Make sure that no two services you need to assign to a pin. 

Small electronics integrated circuit IC on empty printed circuit board ready for hand assembly.jpg

6.RC Oscillators

The clock is a necessary component because it determines that the microcontroller performs the functions in proper sequence at every second. Some microcontrollers that have pre-installed clocks watch timers, also called RC oscillators because they combine the timing of both a capacitor and a resistor. The downside to that is that they have lower precision. Temperature can majorly affect the level of accuracy of oscillation.

For starter kits, they are excellent. But if you are designing something that needs extreme timing accuracy, then these clocks are not advised.

7.Programming Connector

There are only two programming protocols: the JTAG protocol and the Serial Wire Debug protocol.

The SWD only needs five pins to perform clock, i/o, ground, contributor voltage, and reset. If you are looking to design a small board, then this can be the ideal choice.

JTAG connectors can have a large number of pins and suitable for complex programming.

8.Power

The microcontroller needs a contributor voltage to control the components. You can use an external USB charger for this purpose. Calculate the output voltage that feeds in the regulator and the stable output from that to decide what supply is suitable for your design. 1 GPIO pin needs around 24 mA of current, so calculate the source current depending on that. For basic models, the microcontroller can consume up to 300 mA with ease.  

Blue electric current on PCB Printed circuit board.jpg

9. Electrical Rules Check

You can put some errors for pins with the help of colored checks. It will tell you instantly if there are any issues with the board and where that is originating.

The last step is to check that you don’t have any short circuits within bets, pins touching each other, or any pin remaining unconnected.

PCB Layout Design

In this step, you can start placing all the components inside the design of the circuit board. You can then use ‘convert to PCB’ to ensure that the design creates the finalized product with every component in place.

10.Component Placement

This step can check the correct positioning of the parts. If you are using software for PCB design, you can already place components in place. But for better performance of the layout, experts like doing it manually.

Ensure the regulator positions the micro USB connector, and the output is close to the input pin. You can then post the connector for programming in a place you think fits the design. After everything is in place, you can post the resistors, inductors, and the various capacitors we discussed. 

Reasonable design of PCB component placement.jpg

11.PCB Layer Stack

The PCB is a collection of layers stacked over one another. When you have sheets that are capable of conduction, they need to have insulation material between them. You can have a maximum of two of these, preferably at the outsides. As you make the designs more advanced, you can add more conductive layers in even numbers.

12.PCB Wiring

The wiring is generally carried out after component placement. You can do it automatically or manually. The automatic process is not very efficient.

The main principle of routing is that you will need to shorten the height of the traces. It would help if you also lessened how many vias you are using and any 90 degree turns. The higher the power of the evidence, the more critical these principles become.

You can use it through vias if you are trying to reduce the cost of building a prototype. The blind and buried vias tend to be much pricier. The traces should also handle the current flow, or it will melt and cause the board to become damaged.

13.Verification

In the verification, you have to ensure that the design rules are verified and the schema has also been validated.

The DR check will ensure that you have used the right width of trace and left adequate space between marks and the gap between the board and the evidence is correct.

The Drs depends on what circuit board you are designing. So, it would help if you had the right rules before starting the design.

14.Generating Gerbers

After completing verification, you must turn the circuit board design in the standard industry format. This format is known as Gerber. In this format, every layer in the circuit board will have outputs in different files. Silk, assembly, solder mask, paste are the layers. You will also have to create a file that has the positioning details of the components. The manufacturer will use this file when they operate the automatic component placer. You can send these files to the manufacturer of your choice.

PCB Gerber File Generation.jpg

Summary

We analyze the PCB design process through custom microcontroller programming. We gave a brief introduction to the process to ensure that you can follow the steps.

If you need more questions about PCB programming, you can contact us on time.

WellPCB has ten years of WellPCB will provide you with quality service and professional technology.

Hommer
Hi, I am Hommer, the founder of WellPCB. So far we have more than 4,000 customers worldwide. Any questions you can feel free to contact me. Thanks in advance.

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