LPC Microcontrollers中的主题 LPC1768FBD100 USB Host communicates with keyboard issues.

LPC1768FBD100 USB Host communicates with keyboard issues.

lpcware — Wed, 15 Jun 2016 17:50:29 GMT

Content originally posted in LPCWare by CH Wu on Wed Dec 17 20:45:59 MST 2014
Hello,
There's an issue of LPC1768FBD100 that use the USB Host function to communicate with keyboards. The USB Host has a re-try function if the keyboard doesn't feedback to Host that the Host will send request continuously.

The issue only caused while re-try to kenboard for 1 byte. If the communication date is above 2 bytes that the re-try function works fine.

Re: LPC1768FBD100 USB Host communicates with keyboard issues.

lpcware — Wed, 15 Jun 2016 17:50:30 GMT

Content originally posted in LPCWare by CH Wu on Wed Dec 17 21:00:24 MST 2014
Hello,

Add more information.
The re-try function sometimes lose data while sending 1 byte data to the keyboard. It will cause keyboard failed on description.
It looks like chip issue of LPC1768FBD100 of different date codes.
The same USB Host sample code to program to different date code chips.
The date code of 1335A, 1304A, 1403A, 1424A, 1437A are all failed to communicate with keyboard.
The date code of 1328A is always OK.

The viewer to open the USB log file.
http://www.ellisys.com/products/download/visualusb.msi

Re: LPC1768FBD100 USB Host communicates with keyboard issues.

lpcware — Wed, 15 Jun 2016 17:50:31 GMT

Content originally posted in LPCWare by CH Wu on Wed Dec 17 21:03:51 MST 2014
Hello,

Enclosed the sample code of USB Host.

Re: LPC1768FBD100 USB Host communicates with keyboard issues.

lpcware — Wed, 15 Jun 2016 17:50:32 GMT

Content originally posted in LPCWare by CH Wu on Wed Dec 17 21:12:51 MST 2014
Hello,

Enclosed the log files of USB.