New STM32F4 Discovery

Same processor that Justin is using on BlueGenie and that Oberon are working on. BIGGER MEMORY ! Cool huh!

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I like it

The main difference between 427 and 429 MCUs, in 429 MCU memory controller supports SDRAM. 32F429IDISCOVERY already has 8 Mb of SDRAM on board.

Also interesting new line of STM32F401xx MCUs, with unbeatable price starts 3.1$ at 1K with Cortex-M4 core. I think that line is suitable to some small footprint NETMF devices or slave/daisylink and etc. devices with possibility using NETMF.

the 429 vs 427 was a good pick up !

Finally ST released firmware for 32F429IDISCOVERY, and StdPeriph library for STM429 /439 MCUs.

Would be interesting to see “killer” board, with 2MB Flash and 8MB SDRAM.

Still cant get any silicon tho… :frowning:

Not sure about MCU’s , but DISCOVERY boards i think available.

Looked the file “system_stm32f4xx.c” and seems “SystemInit_ExtMemCtl” method enabling SDRAM as system memory. Hope that would not interfere with current system initialization.

I was going to nick a mcu off a discovery but its the wrong pin count, so alas…a little boy waits…

just spin a new board for the 144 pin variant ! :slight_smile:

looks like there’s still no stock on our 100-pin friend. At least the Discovery board is approaching available on Element14

The problem with “killer” boards is that it means different things to different people. For me, for example, “killer” means inexpensive and small, so that rules out SDRAM. Just the onboard RAM on the 429/439 is plenty for me, and the doubled flash makes it plenty easy to run the bigger GCC-compiled firmware.

So for you the 427 is probably fine too, unless theres a hardware feature on 429 that you want (I can’t recall if there’s a difference in things like the number of hardware timers that might have some benefit)

429 adds the LCD-TFT controller to the 427, that’s the difference.

Edit: yeah, the 427 is almost certainly plenty for anything I’m going to do. Since cost is a priority for me, external RAM is unlikely, which makes intensive graphics unlikely.

@ godefroi

I do understand that cost is a big concern for you. This is easy to get from all your posts. I am curious to know you average volume vs cost sensitivity

What is you normal purchase volume for components or boards ?

100s ? 1K pcs ? 10Kpcs ?

How sensitive is your manufacturing to long term availability of components / boards ?

I remember that you were selling cheaper variants of an Ethernet board ? What is the expected long term availability for those boards ?

I am not trying to put you on a spot, my apologies, but I see that you always complain about the cost of development boards and wifi modules and lcd modules. I suspect that you follow some lean manufacturing processes that may be useful for all of us to understand.

And if you have high volume procurements (1K+), we should talk as I may be able to get anything for you real cheap.

I’m a hobbyist, just a cost conscious one. Maybe that’s because I have kids.

Edit: also, maybe, as a person who writes server-side performance-critical software for a living, it’s a little disappointing to me to see hardware such as these MCUs be so underutilized before the community and GHI moves on to the next big thing. A native compiler for something like USBizi would result in better performance than G400 for many, if not most or all things.

Especially with Gadgeteer, the answer to every problem always seems to be “oh, just add another $30/$40/$50 module” when the hardware is already right there.


STM32F429I-DISCO is avaible on Farnell for 21€ so the price is very good…

I wonder if the porting to netmf will be an easy task…
I would really buy this board for learning graphics and LCD displays ;]

Getting the current firmware running is only a couple of line changes.
the extra features…how long is a piece of string… :whistle:

@ Justin

What do you think, is it would be easy or too complicated to enable SDRAM on the board?

@ slawek - after a very brief look into it, i don’t think it will be too hard…famous last words i know :smiley:

One thing is SDRAM, the other is display, the board has a 2.4" QVGA with touch controlled by STMPE811 on I2C.

And a quick demo of the screen: