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Everything ARM and LPC
By jordi
Hello Everybody.

I was in and i don't why i been forward to here, anyway..

I been developing an UAV simulator using a Keil development board, and is working pretty well. Now i tried to port it to an Olimex board (cheaper), but the USB don't want to work. After digging i found out that the component (that looks like a diodes arrangement) is not populated in the board, the component is the U3, and also the capacitors C16 and 17, are not populated, you can see the schematic here:

This is the board im trying to use, that i bought it here in Funny Spark:

I will really appreciate if somebody can tell me which part i need to buy, with the correct package.. (i mean the U3 component)..

I also try to contact olimex support, but they never answer back, i read that they ban all the hotmail, yahoo accounts because they receive tons of spam. Somebody should tell them some basic "antispan" rules , for example they put the contact email in the main page:, as, instead info[@] or, info at olimex dot com... :shock:

Many thanks!!

the NA next to the components means that this component is not populated, so everything is OK with your board, as you can see on the picture on our web they are missing there too.

I don't know why your project for Keil board doesn't work on ours, you have to compare the schematics and see the difference.

We never used Keil, but have mouse demo using USB for EW-ARM and the board USB definitely works ;)

Best regards
By jordi
Hi again,

Mmhh.. :roll: You are right, i didn't saw this little detail (is actually connected), the USB port is connected straight..

This is the Keil schematics: ... matics.pdf

The real chip on the board is the STM32F103RB..

So if you see, the USB is connected exactly in the same PINs and everything, i still don't know why is not working... I even try with the P103, and H103... and the same problem... So i able to load the code, and then when i connect the unit to the PC, it power up, but the PC do not "see" anything, not even the typical "TLUNG" sound.

Now, in the olimex boards, do you know the function of the vias labeled "USB_P" and "DISC" connected to pins PC4 and PC11 , they suppose to be low or high? (i didn't saw that too)..

Many thanks!
By jordi
Now is working, thank you very much....

Jordi Munoz
and the problem was...?

By jordi
Oh I'm sorry... :oops:

You need to pull down the pin PC11 (connected to via "DISC").
If i'm right is just to give the option to disable and enable the USB by software.

Could be useful if the mcu crash, and the system is rebooted by the Watch Dog or something, you can disconnect and reconnect the USB by software during the booting process, otherwise you will have to do it manually...
I will implement it 8)...

Very nice..

Again.. many thanks...
By rico

I have IAR kickstart for STM32, and it is working great.

Now, I am trying to use IAR-EW with STM32-H103. The JTAG
seems to work, but when I try the USBMOUSE sample for STM32-SK,
the USBMOUSE application does not seem to work.

Do I need to set any jumpers, or connect an external power supply?
I only have the IAR JLink-ARM and USB connectors attached.

Or do I need a special version of the USBMOUSE program? The IAR
release did not seem to contain direct support for STM32-H103.

Thank you,
By jordi
Hi Rico,

Well just for reference, i had to move a jumper in my keil board, labeled "VUSB", and then it works.
By rico

Did you have to do anything special to get a reply from Olimex? It has been 5 days now, and I have not seen a response.
By jordi
Hello Rico,

Try to make a new post..