ARM Processor On a Breadboard (hackaday.com)

An anonymous reader writes: A normal Arduino is easy to use and cheap, but it is a reasonably slow 8-bit processor with limited memory. Why do people use them? They are simple to use and set up. Hackaday shows how to take a cheap ($6) 32-bit CPU in a breadboard-friendly package, plug in a small number of parts (resistors, LEDs, and a cable), and use an online Arduino-like IDE to program it. The chip is way more powerful than an 8-bit Arduino and the code is comparable in complexity to an Arduino sketch that does the same thing. It's an easy way to get into embedded without having to suffer through 8-bit processors. And the new Arduinos also use 32-bit ARM, so that's an option too.

Comments

Teensy 3.1

[suso]

Or you just buy a Teensy 3.1 for around $20. Its a 32-bit ARM running at 72 MHz and runs Arduino code.

Re:Teensy 3.1

[geoskd]

and greybeards/hams tend to use obsolete hardware and chant "right tool for the job" because they refuse to learn new things. same guys show up for an interview and wonder why they don't get hired.

Us greybeards would be impressed with these things if there was anything to be impressed about. This thing is far too little far too late. for $10, you can get one of these.

You young uns don't even understand enough to know what to get excited about...

Re:Teensy 3.1

[Tailhook]

Or you just buy a ST Nucleo for around $10. It's a whole family of STM32 ARM Cortex MCUs available on the same board with Arduino Uno R3 compatible headers and every IO pin exposed.

Power usage?

[MobileTatsu-NJG]

My Arduino projects don't require the power of a 32-bit processor, but do run on batteries. How much more (... or less maybe?) power is drawn by this processor?

Re:Power usage?

[subreality]

My Arduino projects don't require the power of a 32-bit processor, but do run on batteries. How much more (... or less maybe?) power is drawn by this processor?

It's reasonably close. If you check the datasheets for "Static Characteristics" / "DC Characteristics" you'll find:

The LPC1114FN28 (the ARM chip) draws 9ma @50 MHz, 6ua @deep-sleep, and 220na @power-down;
The ATMEGA168PA (typical Arduino-ish AVR) draws 4.2ma @8MHz, 0.8ua @power-save, and 0.1ua @power-down.

These numbers are just for the chips - the Arduino draws considerably more (about 40ma @idle), and you can stretch your batteries a lot by hacking it. To give a sense of scale, the power LED on an Arduino probably draws 5-10 ma just by itself.

Note that this is a "Cortex M0" profile ARM chip - M means Microcontroller, and 0 means low-end. This is a 50 MHz chip with 32K of flash and 4K of RAM. It's more powerful than an AVR, but don't expect to boot Linux on your breadboard with this thing... that's a job for the Cortex A (Application) series.

Source:
http://www.nxp.com/documents/d...
http://www.atmel.com/images/At...

Why?

[BitZtream]

So let me be clear, I'm currently work on flight controller software (Drones) that I'm running on both AVR and ARM processors. A 72mhz ARMv6 chip ... meh, give me the AVR at 20mhz.

Its not all about bus width or clock speed. Most AVR instructions are 1 or 2 clock cycles, a handful are 3. ARM is rarely a single clock cycle, 3 being common. From a MHZ perspective, you just practically equalized them. The ARM at 72mhz has very little advantage from a CPU perspective. Having an MMU is nice, but once you start using it, you're likely starting to eat more cycles than you have spare and you're no longer real time.

The AVR has a fully orthogonal instruction set. Writing AVR assembly is actually enjoyable. Unlike ARM (god don't get me started on x86).

AVR chips are durable, you're not going to find an ARM that can handle the load/voltage of an AVR. I could go on for hours.

Of course, on that same note, I could argue for hours about why you'd want to use an ARM over an AVR.

They don't serve the same purposes, its stupid to pretend they really compete against each other. You simply can't take full advantage of the ARM CPU and do a lot of real time work, for example. So just use an AVR for the real time bits and leave the 'business logic' to something else.

The chip is way more powerful than an 8-bit Arduino

No, it isn't, you're just only looking at the MHZ and not the actual real world performance. Its not bad or anything, its just barely better.

and the code is comparable in complexity to an Arduino

Sure, but so is any processor that has an Arduino library for it, whats your point? I can write an entire OS in one line if you want. Of course, that one line is just going to jump to some actual code that does the real work ... kind of like how Arduino sketchs are just standard C++ files which are preprocessed to include the Arduino headers and libraries.

"suffer" from 8 bits?

[rubycodez]

8 bit processors are simple, functional and a joy to program; what moron thinks one "suffers" from using the proper sized tool for a job?