Page 89 - Toucpad robotics C11

Difference: Microcontrollers have relatively small amounts of both program and data memory, just enough for their
specific control tasks. Single Board Computers have much larger amounts of both, often gigabytes of Random Access
Memory and expandable storage for their operating system and applications.
Analogy: Program memory is like a textbook or permanent notes, while data memory is like a whiteboard where you
quickly jot down and erase information during problem-solving.
Input/Output (I/O) Peripherals / Interfaces

Description: These are the channels through which the microcontroller or single board computer interacts with the
outside world – connecting to sensors (inputs) and controlling actuators (outputs). They are crucial for communication
with other components.
Types:
Digital Input/Output Pins: These pins can be configured as either inputs (to read simple ON/OFF signals from
switches, buttons, or basic sensors) or outputs (to turn Light Emitting Diodes on/off, control relays, or send simple
ON/OFF commands).
Analog to Digital Converters (ADCs): Sensors often produce analog signals (like varying voltage based on light intensity
or temperature). Analog to Digital Converters convert these continuous analog signals into digital numbers that the
Central Processing Unit can understand and process.
Pulse Width Modulation (PWM) Outputs: Used to control the speed of Direct Current motors or the position of servo
motors. Pulse Width Modulation creates a series of pulses where the “on” time varies, effectively controlling the average
power supplied.
Communication Interfaces (UART, I2C, SPI, CAN, USB, Ethernet, Wi-Fi): These are specialised hardware modules
that implement the communication protocols we discussed earlier (Universal Asynchronous Receiver-Transmitter,
Inter-Integrated Circuit, Serial Peripheral Interface, Controller Area Network). They allow the microcontroller/Single
Board Computer to exchange data with sensors, motor drivers, other microcontrollers, or even external computers.

Timers/Counters: Used for precise timing, scheduling events, measuring durations, or generating specific frequencies.
Difference: Microcontrollers often have a wide array of basic Input/Output peripherals optimised for real-time control.
Single Board Computers have fewer direct hardware control pins but offer more advanced communication interfaces
(like multiple Universal Serial Bus ports, Ethernet, Wi-Fi, Bluetooth) for networking and connecting to complex peripherals.

Analogy: These are like your senses (reading input) and your hands/voice (producing output), along with the
communication pathways to talk to others.
Clock Unit / Oscillator
Description: This unit generates the timing signals (clock pulses) that synchronise all the operations within the
microcontroller or single board computer. Every instruction execution and data transfer happens in sync with these clock
pulses.
Working Principle: It’s like a metronome for the entire system, ensuring that all internal operations happen in a precisely
timed sequence. The speed of this clock (measured in megahertz - MHz) determines how fast the Central Processing Unit
can execute instructions.
Analogy: The clock unit is like the conductor of an orchestra, ensuring everyone plays in rhythm.

Power Management Unit
Description: This block manages the power supply to the different components of the microcontroller or single board
computer. It regulates voltage, distributes power efficiently, and often includes features for low-power modes to conserve
battery life.
Analogy: This is like the power distribution system in a building, ensuring each part gets the right amount of electricity.

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Computing System