Author Topic: Cannot connect to multiple LPC925 devices  (Read 5493 times)

Daniel.L

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Cannot connect to multiple LPC925 devices
« on: October 02, 2012, 09:56:05 am »
Hi,

I'm having a board with 20 LPC925 devices, each LPC925 connected through a MCP2200 (USB to rs232 converter).

I'm having problem to connect to any device (with Flash Magic or my program). The answers i keep getting is: "Unable to communicate. (configuration)".

I removed all the LPC devices and communicate with only one - and it is working.

Is there any limit using multiple devices with Flash Magic or FM_functions? (fm_connect, erase, and program) or do i need to use another function?

Also, I have noticed that in device manager i see all my COMs starting with "COM56" .. to "COM76", but in the Flash Magic the COMs starting with "COM1" to "COM32".

I'm using win XP, and Flash Magic 6.50.2644.

Thanks in advance,
Daniel


Daniel.L

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Re: Cannot connect to multiple LPC925 devices
« Reply #1 on: October 02, 2012, 10:14:15 am »
Hi,

The answer i'm receiving is: "Unable to communicate. Failed to autobaud". and not configuration..

Thanks in advance,
Daniel

Andy Ayre

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Re: Cannot connect to multiple LPC925 devices
« Reply #2 on: October 03, 2012, 01:03:40 am »
If you don't see the COM port number you want to use then you can type it in directly.

The DLLs support communicating with one device at a time. So you program the first then move on to the second. Providing none of the other devices interfere with the communications.

Andy
Embedded Systems Academy, Inc.
support at esacademy dot com

Daniel.L

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Re: Cannot connect to multiple LPC925 devices
« Reply #3 on: October 04, 2012, 03:25:28 am »
Hi Andy,

Thank you for your quick reply. The problem was in noisy ground on the board..


Daniel.L

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Re: Cannot connect to multiple LPC925 devices
« Reply #4 on: October 04, 2012, 08:53:29 am »
Hi Andy,

Although i cleaned the ground from noise, sometimes i keep receiving errors on connection.

I have searched in the dll functions and used the fm_raw_connect(..), and it always passed successfully.

But i couldn't erase or program the device - Can i use the fm_erase(..) after a raw_connect?.

what is the difference between the fm_connect and the fm_raw_connect functions?

and is there a way to program/erase the device with these funrtions? (raw_transmit/receive)

Thanks in advance,
Daniel

Andy Ayre

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Re: Cannot connect to multiple LPC925 devices
« Reply #5 on: October 04, 2012, 12:19:12 pm »
The raw functions do not know anything about the bootloader. They only open, close, send and receive.

fm_connect autobauds with the device and sends things like the frequency you specified.

I suggest you put a scope on the Rx/Tx and look for more noise, glitches, reflection or other electrical issues that may be confusing the device and/or Flash Magic.

Andy
Embedded Systems Academy, Inc.
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