cancel
Showing results for 
Search instead for 
Did you mean: 

Hardware configuration problem

milton
Associate II
Posted on December 30, 2008 at 14:31

Hardware configuration problem

8 REPLIES 8
daniel8
Associate II
Posted on May 17, 2011 at 09:57

If your code works on a dev board, but not on your PC board, chances are either things are not soldered right, or the design has some fault. The only way anyone will even have the slightest chance of helping would be if you post the schematic of your board, along with the BOM for it (if the schematic does not have the actual values used).

Assuming the schematic is looking good, then it might be an assembly issue.

daniel8
Associate II
Posted on May 17, 2011 at 09:57

Well, if you have firmware that works, and firmware that does not, it is probably not a hardware issue. I don't use IAR, so I cant really look at your project - but if the codebase is the same, it might be a project setting thats causing you grief.

The copy of your schematic is a little poor (can't zoom in to read anything), but it looks to me like your clock frequency is different than the SDK schematic, and that could be causing your issues, since USB will want a 48Mhz clock. Check and make sure that you changed your SCU config to match your 22.7Mhz (as far as I can read it).

daniel8
Associate II
Posted on May 17, 2011 at 09:57

What is the voltage at the base of Q2 when you have your USB pullup enable low? Is the LED always on (the one that should indicate that there is a device on the bus.

The second schematic is a bit better, but still very poor to read. I can't really zoom at all to read the net names without them being very fuzzy. If you have a better copy, send it to d

mailto:awime123@yahoo.com

(remove the space from the first d and a).

Daniel

milton
Associate II
Posted on May 17, 2011 at 09:57

The LED is always on, as far as I use the USB_ENA in the base of the Q1.

Thanks

daniel8
Associate II
Posted on May 17, 2011 at 09:57

Here is my 2c on what may be happening. If your usb device says connected but not recognized, something isn't working on the device end. The discovery is pretty sensitive to timing delays. Make sure your USB code is ready to run when that line goes low.

When you say your code works for 2 seconds the first time, what exactly does that mean? Does the device get recognized as a valid USB device by the computer? Does it hang after it tries to recognize?

Does that same code work on the dev board (without any changes to the project)?

milton
Associate II
Posted on May 17, 2011 at 09:57

The device is connected and recognizedas a valid device, using the device viewer i can see that is a dfu device. I have a blinking device while running and goes off after 2 seconds.

The exact same code works perfecly in the dev board. pretty strange...

Thanks for your help...

daniel8
Associate II
Posted on May 17, 2011 at 09:57

That is pretty weird indeed. Is the code that works dependent on anything that is on other pages of your schematic? If so, I would take anything that depends on any external device and see if that is causing a problem.

Was this board assembled by you or was it done by a professional?

One thing you could try is short the 22 ohm resistors you have on the D- D+ lines. I really don't think that would do it but I am grasping at straws.

Daniel

16-32micros
Associate III
Posted on May 17, 2011 at 09:57

Hi Guys,

Here is my 2cent suggestion : The only difference with IAR-SK kit is that the CD1 ( 48MHz) oscillator which is Y5 in your schematics is not fitted and unuseful since the firmware is coded to run with the internal 48Mhz from PLL. I strongly suggest to remove your Y5 ( 48Mhz) oscillator and it should work 🙂 Let me know if it helps ...

Cheers,

STOne-32.

[ This message was edited by: STOne-32 on 30-12-2008 19:02 ]