The short answer is no, Arduino does not use ARM architecture. Arduino boards are based on 8-bit and 32-bit AVR microcontrollers made by Microchip Technology, whereas ARM processors are designed and licensed by ARM Holdings. However, some Arduino compatible boards do use ARM chips, so there can be some confusion around this.
Background on Arduino
Arduino is an open-source electronics platform that is designed to make it easy for hobbyists, students, and professionals to create electronic projects. At the heart of every Arduino board is an AVR microcontroller chip made by Microchip Technology.
The original Arduino boards used an 8-bit AVR microcontroller called the ATmega8. Current Arduino boards typically use more advanced 8-bit AVR chips like the ATmega328P or the ATmega1280. There are also Arduino boards that use 32-bit AVR chips such as the ATmega2560 or AT90USB1286.
AVR microcontrollers have a modified Harvard architecture which combines flash memory for program storage and SRAM for data storage. They are known for being low cost, low power, simple to program while still providing good performance for many basic applications.
Background on ARM Architecture
ARM is a completely different microcontroller architecture that is based on RISC (Reduced Instruction Set Computer) principles. ARM chips use a load-store architecture and reduced instruction set to achieve high performance and efficiency.
ARM processors are 32-bit or 64-bit chips designed by ARM Holdings. Unlike AVR which is manufactured by Microchip, ARM is an intellectual property company. They design ARM processors and architectures and then license them out to other companies to manufacture and sell them.
Some examples of ARM chips are the Cortex-M0, Cortex-M3, Cortex-M4, and Cortex-A series. Popular manufacturers of ARM chips include STMicroelectronics, NXP, Texas Instruments, and Qualcomm.
ARM chips are known for their low cost, low power consumption, and ubiquity. They can be found in most smartphones, tablets, and many embedded electronics projects.
Key Differences between AVR and ARM
There are some notable differences between AVR microcontrollers used in Arduino boards and ARM processors:
- AVR chips are 8-bit or 32-bit RISC chips while ARM cores are 32-bit or 64-bit.
- AVR uses separate flash memory and SRAM while ARM integrates flash, RAM, and ROM together.
- AVR instruction set is optimized forefficient execution from flash memory while ARM uses load/store model.
- AVR chips have faster I/O while ARM Cortex-M focuses more on CPU and memory performance.
In summary, AVR and ARM have very different architectures even though both are based on RISC principles. AVR excels in low cost and simplicity while ARM focuses on higher performance and efficiency.
Arduino Compatibles with ARM Processors
While mainstream Arduino boards use AVR chips, there are some Arduino compatible boards that are based on ARM processors. These give users the benefit of the Arduino software environment while leveraging the features of 32-bit ARM cores.
Some examples include:
- Arduino Due – Uses Atmel SAM3X8E ARM Cortex-M3 CPU
- Teensy 3.x – Uses NXP/Freescale MK20DX ARM Cortex-M4
- Adafruit Metro M0 – Uses Atmel ATSAMD21 ARM Cortex-M0+
- Seeeduino Cloud – Uses NXP LPC11U24 ARM Cortex-M0
- ESP32 DevKit – Uses Xtensa dual-core CPU
These ARM-based boards can run the Arduino IDE and compile sketch code. However, there may be some differences and limitations compared to the traditional AVR boards.
Benefits of Using ARM with Arduino
Here are some of the benefits of using an Arduino compatible board with an ARM processor:
- Higher performance – ARM cores are generally faster than 8-bit AVR chips.
- More memory – Larger flash and RAM capacity for storing complex programs.
- Floating point unit – Hardware support for faster floating point math operations.
- Peripheral support – More built-in peripherals like USB, Ethernet, timers, etc.
- Multicore options – Some ARM chips offer dual or quad core configurations.
For very demanding Arduino projects that need more processing power, memory, or speed, an ARM chip can provide an advantage. Projects involving audio, video, 3D graphics, computer vision, or network connectivity can benefit from ARM’s capabilities.
Limitations of Using ARM with Arduino
There are also some limitations to keep in mind when using ARM chips on Arduino boards:
- Increased complexity – More difficult to program and debug compared to simpler AVR chips.
- Higher cost – ARM boards are typically more expensive than AVR-based boards.
- Power consumption – Multicore ARM chips can consume substantially more power.
- Compatibility issues – Not all Arduino shields and libraries work with ARM chips.
- Overkill for simpler projects – Projects like basic sensors and LEDs won’t benefit from ARM performance.
For hobbyists and beginners just getting started with Arduino, an AVR board is likely the better choice. But ARM opens up possibilities for very advanced Arduino projects with specialized needs.
While the majority of official Arduino boards are based on AVR microcontrollers, ARM processors do have a place in more advanced Arduino compatible projects. Using an ARM chip allows harnessing more power, but adds complexity compared to traditional 8-bit AVR boards. Each has their own strengths suited for different applications and user needs.