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honey the codewitch22-Jul-23 19:51

22-Jul-23 19:51

You can't really make proper embedded devices with Arduino.

Embedded involves like ZephyrOS, embedded linux, or FreeRTOS. It involves pulling your hair out because you spent the day trying to get SPI working only you didn't read paragraph 3, page 1059 of the hardware reference manual's errata which tells you that SPI won't work at the clock speed you're running at due to a hardware bug.

That's embedded. Cry | :((

Check out my IoT graphics library here:
https://honeythecodewitch.com/gfx

modified 23-Jul-23 2:03am.

BillWoodruff22-Jul-23 20:05

BillWoodruff

22-Jul-23 20:05

got it, thanks: imho, your definition of "embedded" is critical to your work, and, i don't get ... that OMG | :OMG:

advice ?: if i wanted to find a low cost limited functioning robot kit i could cover with my own design cover, that i'd then send commands to by bluetooth ... imagine a small robot dog ...

where would you look ?

thanks, bill

«The mind is not a vessel to be filled but a fire to be kindled» Plutarch

honey the codewitch22-Jul-23 20:07

22-Jul-23 20:07

Honestly, Amazon has a pretty big selection of them. You'll have to get creative about designing a cover for one, but it's a start

Amazon.com : arduino robot[^]

Check out my IoT graphics library here:
https://honeythecodewitch.com/gfx

Cpichols24-Jul-23 2:05

Cpichols

24-Jul-23 2:05

Does this mean you are a pioneer? I think it does.

honey the codewitch24-Jul-23 2:31

24-Jul-23 2:31

Oh plenty of people do embedded. They just aren't talking. $Shucks | :-\$

Check out my IoT graphics library here:
https://honeythecodewitch.com/gfx

Cpichols24-Jul-23 2:54

Cpichols

24-Jul-23 2:54

So you aren't Lewis and Clark, but you could be Laura Ingalls ...

trønderen24-Jul-23 7:25

trønderen

24-Jul-23 7:25

Maybe they are talking, but in more specific forums.

Such as for the Nordic Semiconductor chips: There is quite some traffic at Nordic DevZone[^], bur aimed at those developing for Nordic chips.

Yet you might be able to pick up some useful tricks, if you work with ARM based chips and Zephyr. Lots of issues relate to Zephyr and ARM, not specifically to the Nordic implementation.

sasadler24-Jul-23 7:08

sasadler

24-Jul-23 7:08

In the later half of my embedded career, I was pretty much locked into using TI DSPs. Our 911 products did lots of audio processing (one product had 23 audio channels). TI has lots of samples for their DSP products and since they have a fair number of ARM processors, I'd bet they have samples for them too. You might want to check them out. They also have cheap dev boards where you can try things out.

The only ARM project I worked on was using an ARM7tdmi. It's been around for a long time so it was fairly easy to find sample code on the web.

Member 1488449224-Jul-23 10:25

Member 14884492

24-Jul-23 10:25

Embedded programming is antithetical to pretty much every programming trend of the last 20 years. Note: If you are programming on a board that runs Linux or Android then this discussion is not really aimed at you.

Deeply embedded systems are often built on severely resource constrained hardware. The typical embedded system uses only the memory built into the processor which can be a lot less than you expect. Cortex M0 processers for example come in variants with as little as 32KB FLASH and 2 KB RAM. Note the K vs M.

The primary embedded programming languages is C (not C++ even though your compiler will claim to be C/C++). You will also need assembly code if you do board support packages. If you are not a proficient C coder, then get a good book and teach yourself.

Book recommendations: All of these are older than dirt, but they are classics for a reason and will help you develop the mindset of an effective embedded programmer. Some of these are available as free downloads.

* "Practical C Programming" by Steve Oualline for learning C coding in general.
* "The Art of Embedded Systems" by Jack Gansslle for the general philosophy of embedded programming.
* "Math Toolkit for Real-Time Programming" by Jack Crenshaw for complicated math.
* "Insiders Guide to the Phillips ARM7 based Microcontrollers" by Trevor Martin for using processor resources.

Martin's book on Philips ARM7 is the very best hardware tutorial book I have ever read. Hitex did a great thing for embedded programmers when they released this book as a free download (I think Philips paid for this book). I wish they had done the same thing for Cortex M processors, but life happens and money is not infinite.

https://perswww.kuleuven.be/~u0068190/ARM7/lpc-ARM-book_srn.pdf

Embedded systems can go years between reboots and memory usage management is up to the programmer. Automatic memory allocation (malloc, new, etc.), or anything object oriented can be dangerous. Be wary of any library code that uses these kinds of things. This is one of the reasons why I want the source code for all libraries I use.

Ring buffers are your friend. If properly implemented, buffer overflow exploits just became a thing of the past. You will need to be able to deal with missing data. I use packetized messages with error detection and missing message detection built into the communication protocol (I have been using my own processor to processor packetized protocol that I have used and extended over the last 2 decades).

Every embedded product needs a robust powerup self test function. Run a checksum on your application, perform whatever hardware testing you can and protect your non-volatile memory. Break NVM up into structs that fit within your EEPROM page size. Include a non-zero ID value and checksum in each NVM struct. Add limit tests on multiple choice variables, do anything you can do to detect corrupted NVM data since this is a major risk vector for your code. Alert users as best you can when you detect a problem. Always use the enable pin on EEPROMs (don't just tie them to ground). In some EEPROM devices a single bit change (ESD anyone) can turn a read into a write or erase.

Fight to include an LED the user can see for status display, even if you have an operator display. The happy state is best indicated by a slowly flashing (not a solid on or worse, solid off). You can change the flash rate to indicate different status or mode conditions. Pulsed patterns can be used to indicate specific states or error conditions. And don't use a hardware counter/timer to pulse the LED. Put the LED code in the lowest priority (background) task and make it look at variables in each of the other tasks that indicate if the task is hung up.

Embedded systems often directly control hardware. An electrical engineering background really helps. At a minimum, you need to be able to understand an electronic schematic. If you lack this background then I suggest you take some EE classes. Focus on serial interfaces like I2C and SPI. You will also find yourself using UARTs far more than you ever expected. Martin's Philips ARM7 book is a great resource for best to do this kind of stuff.

You will also sometimes have to meet hard real time requirements which are most easily implemented with an RTOS. If there are any hard real time requirements, then start your designs on the RTOS of your choice, because systems inevitably get more complex over time and porting an existing project to an RTOS is a complete waste of time.

F.Y.I. I am very experience using the Nordic Semi SDK and all I can say, this is not a good resource to learn how to do embedded programming. The SDK was designed to work with a wide variety of ARM processors with a minimum of rewriting and the stuff that actually does the work are extremely well hidden and it is difficult to comprehend by reading the tutorial code in the SDK. The SDK is also extremely inefficient (6 nested subroutine calls to toggle a GPIO bit???). The first project I did using this SDK was reading a high speed ADC over a wireless link (5000 reads per second). It turned out I could read the ADC using a bit-bang implementation of the SPI port 3 times faster than the SDK could using the processor's hardware SPI port. That is pretty pathetic.

Tony Bennett at 96

megaadam21-Jul-23 4:02

megaadam

21-Jul-23 4:02

Another great performer has checked out. I warmly recommend you to find any of his duets with Lady Gaga (e.g: The Lady is a Tramp). An unexpected and amazing cooperation across generations.

"If we don't change direction, we'll end up where we're going"

Re: Tony Bennett at 96

honey the codewitch22-Jul-23 0:10

Another Legend gone - Tony Bennett

22-Jul-23 0:10

I understand he also - while serving in a segregated military - got demoted essentially for fraternizing with black troops, and assigned to corpse duty (exhuming mass graves for soldiers bodies to send home) as punishment.

It didn't stop him. Later he'd march with MLK Jr.

A real mensch.

Check out my IoT graphics library here:
https://honeythecodewitch.com/gfx

Matthew Dennis21-Jul-23 4:01

Matthew Dennis

21-Jul-23 4:01

Legendary musician Tony Bennett dies at 96 - National | Globalnews.ca

Listening to Jazz.fm 91.1 here in Toronto and the DJ is crying.

"Mistakes are prevented by Experience. Experience is gained by making mistakes."

Re: Another Legend gone - Tony Bennett

Matthew Dennis21-Jul-23 4:06

Matthew Dennis

21-Jul-23 4:06

They have thrown out the playlist and are spinning and talking about Tony.
JAZZ.FM91 - Discover Music

"Mistakes are prevented by Experience. Experience is gained by making mistakes."

Re: Another Legend gone - Tony Bennett

Mike Hankey21-Jul-23 4:29

Mike Hankey

21-Jul-23 4:29

Never was a fan but he had talent. R.I.P.

Give me coffee to change the things I can and wine for those I can not!
PartsBin an Electronics Part Organizer - Release Version 1.1.0 JaxCoder.com
Latest Article: Simon Says, A Child's Game

Re: Another Legend gone - Tony Bennett

jeron121-Jul-23 7:32

jeron1

21-Jul-23 7:32

Didn't know a lot of his stuff, but surviving in that business for 70+ years, he obviously had a great deal of talent. Rose | [Rose]

"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment
"Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst
"I don't drink any more... then again, I don't drink any less." - Mike Mullikins uncle

Microsoft, please - get your act together.

OriginalGriff21-Jul-23 2:18

OriginalGriff

21-Jul-23 2:18

Had a question today related to Visual Studio 2013 and I remembered it was still installed on this computer (though I use 2022 these days).

So I tried to run it and it complained that my community edition licence had expired, did I want a new one? "Yes please" I reply. "Sod off" said VS. "I can't get you one".

So I google, and it happened because I stopped using it, and to get it back I'd have to update it to patch 5, and then do this, and that, yada yada yada.

I'll uninstall it. Get the space back! It takes 20 minutes to uninstall, and I'm presented with a dialog:

Dialog

                      Setup completed!
  All specified components have ben uninstalled successfully.



The computer needs to be restarted before starting the product.

                        Restart now

So you want to restart the computer to run the app you just removed? Sigh | :sigh:

"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!

modified 21-Jul-23 8:52am.

Jeremy Falcon21-Jul-23 4:51

Jeremy Falcon

21-Jul-23 4:51

That's because it updated the spyware used to track you during the uninstallation process. All hail Microsoft. Unsure | :~

Jeremy Falcon

Craig Robbins21-Jul-23 6:57

Craig Robbins

21-Jul-23 6:57

Gee Whiz Jeremy -- one might think you don't completely trust Microsoft!

Jeremy Falcon21-Jul-23 7:17

Jeremy Falcon

21-Jul-23 7:17

Ha ha ha. Guilty. Laugh | :laugh:

Jeremy Falcon

Choroid21-Jul-23 7:27

Choroid

21-Jul-23 7:27

I often wonder how MS manages so many products
I had a MS Security Essentials update that kept trying to install
after it installed twice OK So I said HIDE this update that did not work
Like a NumNut I contacted MS Support we played the Update OS Game
Yes I am still running Windows 7 65 bit but MS Security is still updating
One tech that I think know what he was doing we did
sfc/scannnow
DISM.exe
chkdsk/f C:
NO Results message was 98 reparse records
Second Contact with MS Support I was told to update to Widows 10
and that updates for MS Security Essentials were not supported
Thank You Very Much I leave the room now
Still get MS Security Essentials updates
I guess it is still working Waiting on Windows 12 ?
Guess one department does not talk to other departments NO SURPRISE

jeron121-Jul-23 7:36

jeron1

21-Jul-23 7:36

Quote:
Windows 7 65 bit

Well there's your problem, there's an extra bit there. Smile | :)