Introduction to SAMD21 Arm Cortex-M0+ Microcontroller

Hi friends I hope you all are doing well. In today’s post, we will look at Introduction to SAMD21. This is a microcontroller which is a thirty-two-bit less power-consuming device. It processor os ARM Cortex based generally available in thirty-two to sixty-four pinout packaging. The frequency value over which it operates is forty-eight megahertz.

This module is an exit in a simple design with different types of features such as hex code compatibility and linearly address mapping. In today’s post, we will have a detailed look at its working, pinout features, application, and some other parameters. So let’s get started with Introduction to SAMD21.

Introduction to SAMD21

• The ATSAMD21 is an ARM cortex-based microcontroller created by the microchip and uses less power during operation.
• this controller board consists of two fifty-six kilobyte flash memory and a static ram of thirty-two kilobytes.

• The value of frequency required for this board is forty-eight megahertz.
• This MCU can interface with the one-twenty channels.
• The the value of voltage range for which this controller operates is lies from 1.62 volts to 3.63 volts.
• There are 6 communication protocols which are UART, SPI, and I2C are created on the board.
• There are sixteen-bit 3 timers and thirty two bit RTC is provided at this board.

Features of SAMD21

• These are the main features of this controller which are discussed here with the details.
• This board comprises the central processing unit of has a clock speed of forty-eight megahertz.
• This board comprises of two fifty-six kilo byte programmable memory.
• There is static random access memory of thirty-two-kilo bytes created on the board.
• The temperature range over which it operates lies between minus forty to eighty-five degrees centigrade.
• There are six serial peripheral interfaces and six I2C communication protocols exist on the controllers.
• there is a single universal serial bus mode is exists at this board.

• There are fourteen analog to digital inputs on the board.
• There are two comparators used in these controllers.
• The inner oscillator of thirty-two-kilo hertz frequency exists at this controller.
• There are thirty-eight pinouts available on the board.

Technical Features

Microcontroller	ATSAMD21G18, 32-Bit ARM Cortex M0+
Operating Voltage	3.3V
Digital I/O Pins	11
PWM Pins	10
Analog I/O Pins	11
Flash Memory	256KB
SRAM	32KB
Size	23.5mm x 17.5mm

Pinout of SAMD21

• These are the main pinout this board which are discussed here with detail.

Pin 44: VDDIN

• Here power supply of 3.3 volts is provided

Pin 17, 36

• Power supply for GPIO pins 3.3 volt provided

Pin 43

• Regulated 1.2-volt output here

Pin6

• Analog power supply to internal ADC and reference voltage are 3.3

Pin 18, 35, 42

• These are ground pins

Pin 5

• Ground reference for analog  and ADC

Pin 40

• Resets the microcontroller for pulled-to-ground

Pin 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 47, 48

• Analog input pins, used for GPIO, pins PA02 – PA07, PB02 – PB02, PB08 – PB09

13, 14, 15, 16, 19, 20, 21, 22, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 37, 38, 39, 41, 45, 46

• Digital GPIO pins, PA08 – PA25,
• PA30 – PA31,
• PB10 – PB11,
• PB22 – PB23, pins 33 and 34 USB

Block diagram of SAMD21

• The block diagram of this board is shown in the below figure.

SAMD21 Microcontroller Programming

• SAMD21 comes with USB compatibility and is programmed with a USB port through the right bootloader installation.
• Programming is also performed by using the ICSP pin header that is broken on development boards. Programming with these pins needed certain types of programs like Atmel ICE.

Why to use SAMD21?

Large Memory

• SAMD21 comes with 256KB flash memory and with that has extra flash storage so we can store larger blocks of data in the controller. The SAMD21 maximum CPU speed is about 48 MHZ

 Voltage Measurements

• This controller has a 14ADC input pin having a 12-bit resolution and then a 10-bit of ATmega328P. The high resolution shows that bits between 0 and 4095 denoted 0.806mV. If processors are getting power from 3.3 volts that is sensitive voltage measurement.

Integrated USB Controller

• It also has an integrated USB controller that uses USB or a host component. With USB featues can connect a keyboard, mouse, etc. It is also connected as a USB communication protocol where we can connect with computers and use it as a serial port
• As USB support it can connected with a mouse and save data in a USB flash drive.

RTC onboard

• The SAMD21 comes with RTC powered through on board crystal and clocks processor for 48MHz.

Serial Interfaces

• These features make this controller prominent. It comes with 6 configurable serial interfacing in a set form that are converted into UART, I2C master, SPI  master or SPI slave.

SAMD21 VS RP2040

SAMD21

• It comes with processors of ARM® Cortex®-M0+ CPU running at 48 MHz
• Its memory units are
  •  32/64/128/256 KB in-system self-programmable Flash
  •  4/8/16/32 KB SRAM Memory
• It has 12-bit resolution and has features to transform about  350ksps through ADC
• Its operating voltage is 1.62V to 3.63V

RP2040

• It comes with processors of Dual ARM Cortex-M0+ @ 133MHz
• Memory units for this module are
  • 264kB on-chip SRAM in 6 independent banks
  • Support 16MB of off-chip Flash memory through a dedicated QSPI bus
• it has 3 available × 12-bit ADC
• The operating voltage is 3.3V

That is a detailed post about SAMD21 if you have any further query aks in comments, thanks for reading. Have a good day. I hope you have enjoyed this tutorial. To get further interesting posts related to different types of microcontrollers stay tune. Some other related controllers are already discussed with the details.