LPC 2364 unable to communicate (transmit/receive)

[MarkusL]

Hello there,
I have a problem to communicate with my LPC.
I use the Comport over an USB-Com IO-Link Box, and the uC is on an Applikation Board. I can't test it without the Box because the Box is also used as a Level Converter.

I go to the ISP Mode with the IAP command "reinvoke ISP" - therefore I disable the pll and set the internal osc, so that the uC should work with 14,748 MHz.
When I send a "?" (with the console) for Autobaud - I get "Synchronized <CR> <LF> yd" back. so the uC should be in ISP Mode. my Problem is, can't communicate any more - I think it could stick together with the trash at the end of the respons but I dont know why. Or what to do.
I've tried to change baud rates (higher and lower) than 9600, but nothing changed.

What can I do to solve this Problem?
thanks ahead

[Andy Ayre]

I would suspect the way you are resetting the device or your level converter. Probably best to put a scope on the RxD and TxD signals and double-check them. Also start off simple by using Hyperterminal for initial tests so you can see what is going on.

Andy