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1. 

   siy
   Member

   @olimexino, so, you're going to implement powering scheme described above by me?

   Posted 3 years ago #
2. 

   olimexino
   Member

   the power scheme is DC-DC taking 6-16VDC and making 5V/2A source to feed to the USB ports and to the second DCDC which generate 3.3V for the STM32F407

   Posted 3 years ago #
3. 

   siy
   Member

   Yes, this is exactly what I proposed few posts above. By the way, you can use regular LDO for the second DC/DC. With fixed 5V input it will work in rather light conditions. For example, LM3940 is designed specially for this case and it can source up to 1A. Another advantage of this IC is that (unlike x1117) it has tab connected to the ground so it is rather easy to provide required thermal conditions.

   Posted 3 years ago #
4. 

   ThomasB
   Member

   @so now this board will take 6-16VDC power supply
   Hope this will not make the board too expensive...
   Sorry, only a joke ;)

   I'm very happy with this decision. (Could be my idea)
   What's your timeplan with this project (planned time of release) ?

   Posted 3 years ago #
5. 

   olimexino
   Member

   we will route board and may have prototypes next week, if everything goes well then we will run production

   Posted 3 years ago #
6. 

   mabl
   Member

   @olimex:
   I think you mentioned you wanted to make a open source version of a F4 board once. Do you still intend to open up you design?

   Also what's the time frame on the ethernet daughterboard? Will there still be a dedicated (more expensive) STM32-E407 or only the daughterboard over the pin headers?

   Posted 3 years ago #
7. 

   olimexino
   Member

   @mabl STM-H407 will be open source

   with the latest changes with the Ehternet snap-on board I do wonder if we should make the E407 version as it will have nothing more than this board and keeping two separate boards which do the same have no sense

   Posted 3 years ago #
8. 

   mabl
   Member

   @olimexino

   I'd still favor the dedicated Ethernet board (no high speed signals over pins) - but I guess I'll have to live with what you provide ;-)

   Having a 407 board with ethernet and a lot of free IOs which are not used by onboard peripherals is really a dream come true - and even open source!

   Oh, and if there is an ethernet shield, could you build it in a way which has the ethernet port on the same level as the rest of the ports (as proposed in one of you blog comments) - this would be important for casing.

   Posted 3 years ago #
9. 

   olimexino
   Member

   It's too early to predict how the Ethernet will be routed, it's 100MBit Ethernet and we will route it for best signal integrity at first place

   Posted 3 years ago #
10. 

    olimexino
    Member

    just to update you: STM32-H407 routing is complete and we run the prototypes.
    the STM32-E407 development started and I will upload some preliminary schematics and would love to hear your comments.

    on first sight we have to forget about the HS USB as it eats the SPIs which we could use for the SD card and UEXT :(
    also Arduino platform on E407 should be shared with the external memory bus, i.e. you have either Arduino shield either external memory bus but not both at same time.

    Posted 3 years ago #
11. 

    mabl
    Member

    Hi Olimex,

    thanks for the update! I'm definitely looking forward to both boards. Regarding the feature loss through Ethernet - I guess it cannot be helped, everybody has to find his own trade-off. Personally, I don't mind not having Host Support USB.

    Let the schematics come :-)

    Posted 3 years ago #
12. 

    siy
    Member

    @mabl, it's not about host USB support, it's about second on-chip USB controller which supports high speed USB (with external PHY, only full-speed without external PHY). Both USB controllers in F4 support host/OTG, so in fact the loss is not very important, from my point of view.

    Posted 3 years ago #
13. 

    mabl
    Member

    @siy, thx for the hint. I've not looked into USB that much. It seems this loss will have no impact on me.

    Posted 3 years ago #
14. 

    siy
    Member

    @mabl, in fact it is always a trade-off between chip size/price/complexity in use and number/type of simultaneously available interfaces. In this case someone, who will need second USB but don't cares much about number of SPI interfaces, may sacrifice one SPI.

    Posted 3 years ago #
15. 

    gbulmer
    Moderator

    Tsvetan - have you posted the schematics for the boards?

    Posted 3 years ago #

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