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1. 

   bryank
   Member

   I have a few STM32F103RB chips and have 3 of these breakout boards coming this week.

   http://iteadstudio.com/store/index.php?main_page=product_info&cPath=19_21&products_id=271

   By omitting a few of the components from both the Maple schematic and the breakout board I believe I could have a fully functional board that could be programmed with the Maple IDE. I have taken the 2 .PDF schematics and noted which components I foresee needing to omit, can anyone look these over and give me the thumbs up or down before I spend a few hours populating the board? Thanks!

   Maple schematic with omitted components
   http://www.woofiles.com/dl-231029-DtqU9CDz-MapleR5Schematicwithomittedcomponents.pdf

   Breakout board schematic with omitted components
   http://www.woofiles.com/dl-231031-PD8JAl9R-STM32F103RBBreakoutSchematicwithomittedcomponents.pdf

   Posted 4 years ago #
2. 

   bryank
   Member

   Nevermind, found a populated board on Ebay and the pictures of it answer all my questions. Here it is if anyone is interested

   For auction
   http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180634588904&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

   Buy it now
   http://cgi.ebay.com/ARM-Cortex-M3-STM32F103RBT6-MINI-Development-Board-/170573639938?pt=LH_DefaultDomain_0&hash=item27b6fb3102

   Posted 4 years ago #
3. 

   anton
   Member

   To make it functional you should add USB_P divider and a couple of transistors from DISK pin to USB D+. Or it can be one pnp transistor: http://easyelectronics.ru/img/ARM_kurs/Flashing/stm_32_usb.jpg

   Posted 4 years ago #
4. 

   x893
   Member

   I think 22pF - not a 22nF

   Posted 4 years ago #
5. 

   bryank
   Member

   Thanks, especially for the drawing! Ill compare your drawing with the schematic of the Maple tonight to see what I missed. If you care to explain the purpose of this circuit I would definitely listen. Appreciate it!

   Posted 4 years ago #
6. 

   anton
   Member

   The circuit simulates USB cable disconnection. After it host OS changes device driver.
   http://leaflabs.com/docs/bootloader.html

   Posted 4 years ago #
7. 

   bryank
   Member

   Quick question about the possibility of avoiding that circuit. There is an STM32 discovery thread that is talking about using that development board with the Maple library and member geoffreymbrown says the following:

   "there's no soft disconnect circuitry so it isn't feasible
   to switch between dfu and serial modes under software control. I modified the bootloader to go directly to user code (without initializing the usb connection for dfu)
   if the button is not pressed."

   If I could get a hold of this modified bootloader could I to upload sketches without this circuit?

   Posted 4 years ago #
8. 

   anton
   Member

   There is another interesting opportunity.
   This program http://easyelectronics.ru/img/ARM_kurs/Flashing/rtx_f103_boot.zip
   generates bootloader which presents memory of stm32f103 as disk device with one file
   firmware.bin. You just copy your file over.
   It loads binary from 0x8002000 address, so you need to change linker script. BOOT1 pin used to swich from botloader to user code mode. 0 - bootloader, 1 - user.

   Posted 4 years ago #
9. 

   poslathian
   LeafLabs

   mBed style. I didnt realize there was a good example of this in the public domain. Thanks!

   Posted 4 years ago #

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