Table of contents
- What is microcontroller?
- How does microcontroller work?
- The core elements of a microcontroller
- Key features of microcontroller
- Applications of Microcontrollers
- How to choose a microcontroller?
What is microcontroller?
An Embedded IC‘s microcontroller is a small integrated circuit that controls a single process. On a single chip, a typical microcontroller has a CPU, memory, and input/output (I/O) peripherals.Microcontrollers, also known as embedded controllers or microcontroller units (MCU), can be found in a variety of devices, including vending machines, robotics, office equipment, medical devices, and office machines. They are essentially small, straightforward personal computers (PCs) without a complicated front-end operating system (OS) that are used to control specific details of larger components.
How does microcontroller work?
To control a single device function, a microcontroller is integrated into a system. It accomplishesthis by utilizing its core CPU to evaluate data that it receives from its I/O peripherals. The microcontroller receives temporary data that is stored in its data memory, where the microprocessor accesses it and employs program memory instructions to interpret and apply the incoming data. It then communicates and takes the necessary action using its I/O peripherals.Numerous gadgets and systems make use of microcontrollers. Devices frequently employ a number of microcontrollers, which cooperate to carry out the device's many functions.
An automobile, for instance, might contain a large number of microcontrollers that manage a variety of internal systems, including the anti-lock brake system, traction control, fuel injection, and suspension control. To inform the appropriate actions, all the microcontrollers communicate with one another. Some may just interface with other microcontrollers, while others may connect to a more sophisticated central computer within the vehicle. They use their I/O peripherals to send and receive data, process that data, and carry out the tasks for which it was intended.
The core elements of a microcontroller
| Processor (CPU) | The brain of the gadget is supposed to be a CPU. It interprets and reacts to several commands that control how the microcontroller operates. This calls for doing elementary logic, I/O, and arithmetic operations. Additionally, it carries out data transmission activities that send commands to other embedded system parts. |
| Memory | The data that a processor receives and uses to carry out instructions that it has been designed to carry out is stored in a microcontroller's memory. |
| I/O peripherals | The processor's connection to the outside world is made through its input and output devices. Information is received by the input ports and sent as binary data to the CPU. After receiving the data, the processor transmits the appropriate instructions to output devices that carry out activities not controlled by the microcontroller. |
| Analog to Digital Converter (ADC) | A circuit known as an ADC transforms analog signals into digital signals. It enables the microcontroller's central CPU to communicate with external analog devices like sensors.
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| Digital to Analog Converter | The processor at the heart of the microcontroller can send its outgoing signals to external analog components thanks to a DAC, which serves the opposite purpose of an ADC.
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| System bus
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The system bus serves as a connecting link between each microcontroller component. |
| Serial port | One type of I/O connection that enables the microcontroller to interface to external components is the serial port. It performs a similar purpose to a USB or parallel port, but it exchanges bits differently. |
Key features of microcontroller
High functional integration: Microcontrollers are referred to as single-chip computers because they include on-chip memory, I/O circuitry, and other circuitries that enable them to act as tiny standalone computers without the need for extra supporting circuitry.
Microcontrollers commonly employ EPROM or E PROM as its storage device to offer flexibility and field programmability, which increases their usability. Once the software has been validated for accuracy, many microcontrollers can be programmed for use in embedded systems.
Small Size: Unlike a computer microprocessor, a microcontroller is built to do specific tasks. As a result, there aren't many RAM, ROM, or other peripheral hardware requirements. Thus, everything is integrated into a single chip thus significantly reducing the overall size.
Low Cost: Because microcontrollers have less peripherals, RAM, and ROM packed onto a single chip than microprocessors, they are far more affordable than microprocessors.
Lower energy consumption: Because a microcontroller uses a smaller set of hardware, including RAM, ROM, and other peripherals contained in a single chip, it consumes relatively little power.
Applications of Microcontrollers
- LEDs are examples of light-sensing and control devices.
- Chimneys and other temperature-sensing and -controlling appliances.
- Fire alarms are fire detection and safety equipment.
- Measuring tools such as a voltmeter.
How to choose a microcontroller?
Power supply:
1: To determine how much power or the maximum current required (mA), take into account the system's power supply requirements, such as the system's need for several power sources, such as 24V, 12V, 5V or 3.3V, etc. The formula “total power supply = 2 & TImes; total device power” can be used to compute the total power supply, which should allow for a specific margin.
2: Think about the device and chip on the power supply demand fluctuations. Permit power variations of no more than 5%. In general, a reference voltage of 1% is needed for the A/D converter chip.
3: Think about if the operational power supply is an external power supply or a power module.
A/D circuit and D / A circuit:
A/D circuit: to be clear about the basic principles of front-end sampling, resistive, current and voltage sensors using different acquisition circuits. If the collected signal is weak, but also consider how to amplify the signal.
D / A circuit: Consider the MCU pins through which the output circuit to control the actual object.
Consider Low Power Consumption:
1: Not every bus signal needs to be raised. Power consumption difficulties with pull-up and pull-down resistors should also be taken into account. A straightforward input signal is pulled by pull-up and pull-down resistors; the current is only a few tens of microamps below. However, the current while drawing a driven signal can reach milliamps. Therefore, the effect of pull-up and pull-down resistors on the system's overall power consumption must be taken into account.
2: Use the I/O port sparingly; if you do, a little interference from the outside world could cause the input signal to oscillate repeatedly. The MOS device's power consumption largely depends on the number of gate flip-flops.
3: Consideration must also be given to some minor peripheral chips' power requirements. It is challenging to calculate the power consumption of a chip because it is primarily based on the current flowing through the pin. For instance, some chip pins may consume less than 1 mA of power when there is no load, but as the load increases, the power consumption may climb significantly.
Consider low cost:
1: The appropriate selection of capacitance and resistance values. For instance, if you want to use a pull-up resistor, you can use one between 4.5K and 5.3K. However, if you choose 5K thinking there is a market for it, there isn't one. The closest resistance value to 5K is 4.99K (precision 1%), then 5.1K (precision 5%), with a precision cost of 4.7K greater than the resistance value of the resistor by two times and by 20%. Only 1, 1.5, 2.2, 3.3, 4.7, and 6.8 categories (with 10 integer multiples) are 20% accurate for capacitance; if you choose other values, you must utilize them with higher precision, which increases cost and effort while providing no benefits.
2: The selection of lighting. What shade should the indicator on the panel be? Some people base their decisions on colors, such as their preferred shade of blue. The price of other colors, such as red, green, yellow, and orange, is typically less than 5 cents, regardless of the size of the package (5mm or less), whereas blue was only created in the past three or four years, has poor technical maturity and supply stability, and is therefore four or five times more expensive. (Remember that this happened a while ago.)
3: Don't go for the greatest option available. Not every aspect of a high-speed system operates at high speed, and as device speed increases, costs nearly double while signal integrity problems also have a significant negative impact.
