How to start?
Most of the electronics needs some brain to be able to make something meaningful. That brain is processor. There are countless processors from simple with AVR architecture to more complex like ARM processors. Processor choice is depending on usage. You have to consider many parameters like price, size of package, number of GPIO pins (general input output pins) energy consumption, memory size, processor frequency and other parameters. One of the most important parameters is how easy is to develop on that platform. The easiest way to start developing is to start with Development kits. I will introduce you the most known Arduino, Raspberry PI, ESP32.
It was 2005 when prototyping platform Arduino as educational tool for students based on 8-bit Atmel processors was born. The Arduino community created graphical integrated development environment (IDE) and libraries which significantly simplified work with GPIO ports.
Students can create super easy software that will control PWM (pulse width modulated) based on voltage measured on other pin of processor. As a user, instead of assembling breadboard with processor and all necessary components, you just plug Arduino board to the computer with USB cable, open programming interface and choose one from many examples with most used functions and use-case scenarios.
- price (you can get one of these from 3 USD), simple development, size, low power
- limited memory for code (only few kilobytes for software), slow CPU clock
- Sensors processing, controlling LEDs, motors and other actuators, sending data
Raspberry PI, just like Arduino was created as project for students supporting informatics on schools. Unlike Arduino, Raspberry PI is complete PC in the size of the bank card. It runs Linux operating system, it has all input and output interfaces necessary for work on this PC like USB, HDMI and ethernet. It has also GPIO to work with. Raspberry PI is however multiple time more powerful than Arduino and it can handle more power demanding applications like AI, computer vision, video transmission etc.
- High computing power, price, work just like with PC, very good support on internet, internet connection
- Higher current consumption, booting time
- Smart home control, video streaming, control of actuators, robots
- high computing power, price, WIFI+bluetooth, low current consumption
- Higher power consumption
- Communication module, IOT, actuators control, displaying sensor data
In case you want choose specific processor or you can’t find right development kit and you don’t want create whole PCB for it, you can use prototyping board (breadboard). It’s a board with series of holes which are electrically connected together in lines and divided horizontally into left and right side. You can insert components into board to create prototype without soldering.
After you proved the functionality of the prototype with development kit or breadboard, you can rewrite this connection to EDA (electronic design automation) software like Eagle or KiCad. The process of PCB design starts with block scheme. Block scheme is map of connections between components without knowledge of their actual position on the PCB.
After block scheme is created you have to switch to “PCB design” mode. You will draw PCB shape and place all components on the PCB. Then you have connect components with routes. There are two ways how to create routes on PCB. The first is Autoroute which is powerful tool for automatic creating routes. This method however is not the most optimal regarding the PCB properties. Sometimes even autoroute can’t resolve some routes so it’s better do it yourself. This topic is for whole blog so i will cover it in future blog.
After the scheme and PCB design is done we can produce the final PCB. You can easy create the PCB at home. You can choose from several methods. For simple PCB you can stand with universal PCB. There are holes on the universal PCB similar to breadboard. Horizontal lines on the board are connected together. Connection between lines are made with cables or tin.
Ironing method is consist of printing routes design with laser printer on transparent foil or paper.
Then you will put the foil or paper on laminated copper board and iron it. The PCB design will transfer on the copper board.
Afterwards sink the board to the solution of FeCl3 which dissolve all copper instead routes. Then rinse the PCB with water and clean all remaining toner from routes by rubbing alcohol and PCB is done. All steps will be in covered future blog.
very cheap and fast prototyping
Toner is not always transferred very well on the board, so some routes can be broken and need to be joined by tin.
Not good for thinner routes.