STM32 series µController questions.

Hey Guys,

Anyone here have much experience with the STM32 series µControllers?

Looking at using one but I can't seem to decipher whether or not it has non-volatile storage for storing user settings etc during power down.

I can't tell if they are saying in the datasheet whether or not my program will be able to allocate storage in the actual flash, or if I would need to connect an external eeprom?

Currently looking at this device. STM32L476xx

http://datasheet.octopart.com/STM32L476RGT6-STMicroelectronics-datasheet-37534169.pdf

Up to 1MB of flash means you can save a lifetime of poop.  While you need to figure out the secret handshakes.

JR

You can definitely use the internal flash for storing your user data. Take a look at the reference manual http://www.st.com/st-web-ui/static/active/en/resource/technical/document/reference_manual/DM00083560.pdf page 77 ("Embedded Flash memory (FLASH)"). There's probably code around that provides a nice API to use this.

JohnRoberts said:

Up to 1MB of flash means you can save a lifetime of poop.  While you need to figure out the secret handshakes.

JR

Click to expand...

SEcret Handshakes? lol

Think I have finally settled on ,,

STM32F405VG

damn it's hard to choose with so many out there...

bradholland said:

JohnRoberts said:

Up to 1MB of flash means you can save a lifetime of poop.  While you need to figure out the secret handshakes.

JR

Click to expand...

SEcret Handshakes? lol

Click to expand...

I am self taught programming microprocessors and often the (Microchip) documentation is pretty thin. Sometimes it is just wrong.

Trust but verify, and when in doubt debug...

JR

Hi there,

I massively use the STM32F407 on my day job. For me it's one of the best documented processors I have ever worked with.
IMHO, this is due to the low-cost evaluation boards, like the discovery or nucleo series. One big knowledge base for me is the German web site: http://mikrocontroller.bplaced.net/wordpress/?page_id=6
Even if the site is in German, you can download the code or CoIDE project files with English comments.

There are examples for almost every peripheral available. I am sure you will find code for the embedded flash as well.

Cheers,
Carsten

bradholland said:

Think I have finally settled on ,,

STM32F405VG

damn it's hard to choose with so many out there...

Click to expand...

It starts with requirements: what does the processor have to do?  That is, what peripherals are required, and what kind of processing do you need? 

A bit of ARM advice: when you find what you think is a suitable device, do the hard work of determining whether you can use all of the peripherals you want. Often the peripherals share I/O ports, so you have to figure out how to configure everything. For example, I was looking at using an NXP LCP18xx-series ARM for something, until I realized that I couldn't use the I2S port and the quad-serial memory interface at the same time.

And every processor vendor has a different way of muxing the peripherals. Silicon Labs has a "priority crossbar," which changes pin assignments depending on whether each peripheral is enabled or not (it's not as weird as it sounds). For each I/O pin, Atmel has a mux which selects one of two peripherals, or lets you drive the I/O pin directly (bit-banging). NXP's muxing is weird. I looked at ST briefly, so I don't know what they do.

Most of the vendors offer some kind of software configuration tool, which lets you choose your peripherals and then it shows you any conflicts.

For firmware development, the GNU ARM Eclipse environment knows about STM32F parts right out of the box.

Oh, one more thing: all of the ARM vendors provide libraries to get you started. Some of them can be quite bloated, requiring a larger flash program memory store than you'd expect.

Good luck.

-a