Smaller alternative to discovery-board?

[FantomXR]

Hey people,

I took a look into the drivers that come with MIOS. It seems that all STM32F4xx could be supported. Is that right? 
I ask because I'm looking for a smaller alternative to the DISCOVERY-board which has a big footprint. Here f.e. you can find a much smaller board with has a STM32F405 on board:

http://re.reworld.eu/de/produkte/s64dil-405/index.htm

Any informations on this?

Best,
Chris

[Psykhaze]

Hi Chris,
maybe something like this might help ? :  https://fr.aliexpress.com/item/STM32F4discovery-STM32F407VGT6-ARM-Cortex-M4-32bit-MCU-Core-Development-Board/32828318079.html ,
it's still bigger than your purposal that i would have preffered something like https://fr.aliexpress.com/item/Minimum-system-board-STM32F103RBT6-development-board-bottom-with-adapter-plate-Combo/32761293191.html
to stay compatible with existant firmware/MCU used . But maybe still bigger that what you might expect.
Hope it helped anyway :)
regards,
Jerome

[Antichambre]

Hello Chris, salut Jerome ;)

Chris, you can use any prototyping board which support STM32F407V, for using the existing MIOS32 drivers you just need to respect the pinout.
@latigid on already proposes an alternative to the disco

Best Bruno.

Edited January 16, 2018 by Antichambre

[latigid on]

Even though some of the other breakouts are more ideal in terms of form, they don't always include every pin. You should take care with the particular MCU used as it may have reduced performance. The Waveshare stuff looks fairly trustworthy with regards to quality, documentation, support, etc. 

[FantomXR]

Thanks for your suggestions!

@latigid on: Your design has a big advantage: I hate those Micro-USB connectors on the DISCO-board. So this will be a huge improvement. Also it looks a bit smaller as the DISCO-board. How about the PCBs? Do you plan to upload the layout? 
I designed my own breakout-board for the DISCO-board. So it has a bunch of connectors that the MIDIbox-core doesn't have. Also some regulators and another micro-sd-card slot. I'd like to take your design, make those changes and give it a try. Is there any chance to get the eagle-files from you?

@Antichambre: I've read in the link you posted that you already designed an own stm32f4-PCB. Any progress on this? To be honest: I'd really like to create my own stm32f4-PCB. But I have no clue about what is needed for a minimal circuit. Your PCB looks like it has everything on board and I just need to make my modifications to it. SMD soldering is not a problem. I have a reflow oven.

We could also think of a core, that is especially made for midibox-users. I could make them in my reflow oven and sell them to others if there is any interest. 

[Antichambre]

55 minutes ago, FantomXR said:

Any progress on this?

No I made it when the disco version of the core was difficult to find, before Latigid on version too. it's useless now.
 

57 minutes ago, FantomXR said:

But I have no clue about what is needed for a minimal circuit.

All of this informations are in the datasheet, you can get a good idea of what is the minimum by studying all the board which are on the market, more than that you need to know what you will have to connect to it and keep the pinout compatible with the MIOS32.
What is your exact needs and your real constraints for such a board? Are you sure the Wavecore can not fit your design?
in all honesty I know we are on an open-source platform. but to create such a pcb is a lot of time and work, I'm going to have a little trouble letting it go like that ;)

Best Bruno

[FantomXR]

Just now, Antichambre said:

What is your exact needs and your real constraints for such a board? Are you sure the Wavecore can not fit your design?

I'm building a lot of keyboards with MIDIbox and space is a problem at any time. So the main reason is, to create a PCB, that has just those components on board, which are necessary for that application (including the shift registers for scanning). This would save space and cables.

Like I said: The Wavecore seems to be a huge improvement already. So I'm curious if latigid is willing to share his project ;) 

Maybe you are right: I could go through all schematics of those boards which are on the market. But as you said: This is really time consuming. I took a look into the waveshare-407-schematic. This looks promising! Very few parts and a good oversight. The datasheet of the disco-board is really killing...