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ARMing a Breadboard – Everyone Should Program an ARM

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Re: ARMing a Breadboard – Everyone Should Program an ARM

#31

Post by klagermkii »

ChuckMcM wrote: post #13

I too am often surprised at how often people reach for an Atmel 8 bit AVR chip rather than an ARM. It is a testament to the momentum that Atmel built, the avr-freaks community and the amazing cost effectiveness of it all. But now we're seeing ARM chips with built in clocks, and fewer base components required and I think the end of that AVR dominance is on the horizon. And that is why Dialog is buying Atmel[1]. Gettin…

Most hobby electronics projects aren't really CPU limited though, so using ARM doesn't really bring relevant advantages. Having a standard platform, including the peripherals like PWM/ADC/timer etc which are going to vary wildly between ARM implementations, is far more important for people starting out and are trying to solve their problems via Google.

The 5V chips are also better at taking punches from miswired projects.

Re: ARMing a Breadboard – Everyone Should Program an ARM

#32

Post by d9fb698e010974b »

MissingGear wrote: post #14

An an electronics hobbyist wannabe, may I please have the links for parts / assembling the 5v to 3.3v circuit needed to power this thing ?

Others are suggesting power supplies, but I think you can just use a voltage divider from a 5V supply. Like maybe a 2.7K resistor followed by a 5.6K to ground?

Re: ARMing a Breadboard – Everyone Should Program an ARM

#33

Post by analog31 »

MissingGear wrote: post #14

An an electronics hobbyist wannabe, may I please have the links for parts / assembling the 5v to 3.3v circuit needed to power this thing ?

Since you also need a USB-to-serial converter, either of these boards include onboard 3.3 V regulated power output, probably with enough current to run a microcontroller:

https://www.sparkfun.com/products/11736

http://www.adafruit.com/products/284

In addition, this is an easy to apply 3.3 V regulator chip, in a package that's compatible with a breadboard:

https://www.adafruit.com/products/2166

Re: ARMing a Breadboard – Everyone Should Program an ARM

#34

Post by analog31 »

d9fb698e010974b wrote: post #32
MissingGear wrote: post #14

An an electronics hobbyist wannabe, may I please have the links for parts / assembling the 5v to 3.3v circuit needed to power this thing ?

Others are suggesting power supplies, but I think you can just use a voltage divider from a 5V supply. Like maybe a 2.7K resistor followed by a 5.6K to ground?

It needs to be regulated, because the microcontroller draws varying amounts of current. But a simple regulator is just a three-legged IC and a capacitor.

Re: ARMing a Breadboard – Everyone Should Program an ARM

#35

Post by deutronium »

d9fb698e010974b wrote: post #32
MissingGear wrote: post #14

An an electronics hobbyist wannabe, may I please have the links for parts / assembling the 5v to 3.3v circuit needed to power this thing ?

Others are suggesting power supplies, but I think you can just use a voltage divider from a 5V supply. Like maybe a 2.7K resistor followed by a 5.6K to ground?

You really don't want to do that imo.

Re: ARMing a Breadboard – Everyone Should Program an ARM

#36

Post by sokoloff »

the-dude wrote: post #27
ChuckMcM wrote: post #13

I too am often surprised at how often people reach for an Atmel 8 bit AVR chip rather than an ARM. It is a testament to the momentum that Atmel built, the avr-freaks community and the amazing cost effectiveness of it all. But now we're seeing ARM chips with built in clocks, and fewer base components required and I think the end of that AVR dominance is on the horizon. And that is why Dialog is buying Atmel[1]. Gettin…

With a development board: yes. But if you want to do hack something on a breadboard or make your own PCB it is really convenient to have THD ( through hole device ). The ARM used in the article is the only TDH available AFAIK.

Breadboard, yes, but if you're making your own PCB, I'd argue that SMD for the micro is easier (not to include BGA, but everything with perimeter pins, I think SMD is easier, even for the home hobbyist).

For SMD-only parts, there are SMD to DIP adapters readily available to let you use them on breadboards; for relatively low-frequency digital work, there's no problem using them, so being available in through-hole isn't a practical advantage.

Re: ARMing a Breadboard – Everyone Should Program an ARM

#37

Post by pcwalton »

0xcde4c3db wrote: post #10

If you're interested in low-level code (assembly, JITs, Forth, etc.), note that official documentation for the ARM ISA has considerable encumbrance. It's not like most architectures where you just go to the manufacturer's website and download a PDF of the programming manual; ARM makes you register an account and agree to a rather restrictive clickwrap license (something to the effect of "you're only allowed to use th…

The situation still isn't great, but this has gotten better over time with the documentation on infocenter.arm.com, which Google usually pulls up as a top result when you search for various ARM instructions.

For example, Googling for "arm tbl" brings up this: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc....

which contains links to the rest of the AArch64 instruction set. The documentation has scary "Superseded" notices, but it's all basically accurate and it's enough to do low-level programming.

Re: ARMing a Breadboard – Everyone Should Program an ARM

#38

Post by 0xcde4c3db »

d9fb698e010974b wrote: post #28
0xcde4c3db wrote: post #10

If you're interested in low-level code (assembly, JITs, Forth, etc.), note that official documentation for the ARM ISA has considerable encumbrance. It's not like most architectures where you just go to the manufacturer's website and download a PDF of the programming manual; ARM makes you register an account and agree to a rather restrictive clickwrap license (something to the effect of "you're only allowed to use th…

That shouldn't encumber most people though. How many people who don't already know that have the skills to seriously compete with ARM? Probably none.

Historically, it hasn't really taken "serious competition" to invite threats. There's a reason that the best-known open-source ARM implementation explicitly only targets ARMv2 (which dates from the days when the "A" stood for "Acorn") [1].

That said, people who just want to play with ARM-based hardware can get pretty far by leaning on the GNU support and third-party documentation (there are some Game Boy Advance documents that cover the ARMv4 instruction set, for example).

[1]: http://opencores.org/project,amber

Re: ARMing a Breadboard – Everyone Should Program an ARM

#39

Post by ChuckMcM »

klagermkii wrote: post #31
ChuckMcM wrote: post #13

I too am often surprised at how often people reach for an Atmel 8 bit AVR chip rather than an ARM. It is a testament to the momentum that Atmel built, the avr-freaks community and the amazing cost effectiveness of it all. But now we're seeing ARM chips with built in clocks, and fewer base components required and I think the end of that AVR dominance is on the horizon. And that is why Dialog is buying Atmel[1]. Gettin…

Most hobby electronics projects aren't really CPU limited though, so using ARM doesn't really bring relevant advantages. Having a standard platform, including the peripherals like PWM/ADC/timer etc which are going to vary wildly between ARM implementations, is far more important for people starting out and are trying to solve their problems via Google. The 5V chips are also better at taking punches from miswired proj…

My experience is that most hobby projects are RAM limited when people are using the AVR chips. Whether its trying to hold a copy of an LCD view, or any sort of moderate data structure. The ATMega328 is 8K of RAM. The M0+ chips seems to all come with 64K of RAM, and given that folks are writing in C/C++ rather than Assembler that is quite helpful.

I agree with you on the general tolerances to abuse though. I've filled out a couple of surveys sent to me by semiconductor folks (I often get one after attending a free training session) and I've mentioned several times that a short/overvoltage hardened chip would be a useful thing for me. You can do that with off chip parts but since manufacturers are wondering what to do with an abundance of silicon surface area to distinguish their products, I continue to suggest that would be one way.

Re: ARMing a Breadboard – Everyone Should Program an ARM

#40

Post by ChuckMcM »

sokoloff wrote: post #36
the-dude wrote: post #27

Earlier quoted context omitted.

With a development board: yes. But if you want to do hack something on a breadboard or make your own PCB it is really convenient to have THD ( through hole device ). The ARM used in the article is the only TDH available AFAIK.

Breadboard, yes, but if you're making your own PCB, I'd argue that SMD for the micro is easier (not to include BGA, but everything with perimeter pins, I think SMD is easier, even for the home hobbyist). For SMD-only parts, there are SMD to DIP adapters readily available to let you use them on breadboards; for relatively low-frequency digital work, there's no problem using them, so being available in through-hole isn…

And the "winner" is something like the Teensy which is an SMD part but its mounted on a board that gives it pins like a DIP chip.
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