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Mikael Patel
Mikael Patel
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Is it a really bad idea to use malloc() and free() with Arduino?

The short answer is yes. Below isare the reasons why:

It is all about understanding what an MPU is and how to program within the constraints of the available resources. The Arduino Uno uses an ATmega328p MPU with 32KB ISP flash memory, 1024B EEPROM, and 2KB SRAM. That is not a lot of memory resources.

Remember that the 2KB SRAM is used for all global variables, string literals, stack and possible usage of the heap. The stack also needs to have head room for an ISR.

The memory layout is:

SRAM map

Todays PC/laptops have more than 1.000.000 times the amount of memory. A 1 Mbyte default stack space per thread is not uncommon but totally unrealistic on an MPU.

EmbeddedAn embedded software project has to do a resource budget. This is estimating ISR latency, necessary memory space, compute power, instruction cycles, etc. There isare unfortunately no free-lunches and hard real-time embedded programming is the most difficult of programming skills to master.

Is it a really bad idea to use malloc() and free() with Arduino?

The short answer is yes. Below is the reasons why:

It is all about understanding what an MPU is and how to program within the constraints of the available resources. The Arduino Uno uses an ATmega328p MPU with 32KB ISP flash memory, 1024B EEPROM, and 2KB SRAM. That is not a lot of memory resources.

Remember that the 2KB SRAM is used for all global variables, string literals, stack and possible usage of the heap. The stack also needs to have head room for an ISR.

The memory layout is:

SRAM map

Todays PC/laptops have more than 1.000.000 times the amount of memory. A 1 Mbyte default stack space per thread is not uncommon but totally unrealistic on an MPU.

Embedded software project has to do a resource budget. This is estimating ISR latency, necessary memory space, compute power, instruction cycles, etc. There is unfortunately no free-lunches and hard real-time embedded programming is the most difficult of programming skills to master.

Is it a really bad idea to use malloc() and free() with Arduino?

The short answer is yes. Below are the reasons why:

It is all about understanding what an MPU is and how to program within the constraints of the available resources. The Arduino Uno uses an ATmega328p MPU with 32KB ISP flash memory, 1024B EEPROM, and 2KB SRAM. That is not a lot of memory resources.

Remember that the 2KB SRAM is used for all global variables, string literals, stack and possible usage of the heap. The stack also needs to have head room for an ISR.

The memory layout is:

SRAM map

Todays PC/laptops have more than 1.000.000 times the amount of memory. A 1 Mbyte default stack space per thread is not uncommon but totally unrealistic on an MPU.

An embedded software project has to do a resource budget. This is estimating ISR latency, necessary memory space, compute power, instruction cycles, etc. There are unfortunately no free-lunches and hard real-time embedded programming is the most difficult of programming skills to master.

Source Link
Mikael Patel
Mikael Patel
  • 8k
  • 2
  • 16
  • 21

Is it a really bad idea to use malloc() and free() with Arduino?

The short answer is yes. Below is the reasons why:

It is all about understanding what an MPU is and how to program within the constraints of the available resources. The Arduino Uno uses an ATmega328p MPU with 32KB ISP flash memory, 1024B EEPROM, and 2KB SRAM. That is not a lot of memory resources.

Remember that the 2KB SRAM is used for all global variables, string literals, stack and possible usage of the heap. The stack also needs to have head room for an ISR.

The memory layout is:

SRAM map

Todays PC/laptops have more than 1.000.000 times the amount of memory. A 1 Mbyte default stack space per thread is not uncommon but totally unrealistic on an MPU.

Embedded software project has to do a resource budget. This is estimating ISR latency, necessary memory space, compute power, instruction cycles, etc. There is unfortunately no free-lunches and hard real-time embedded programming is the most difficult of programming skills to master.