topic Re: LPC1343 USB To Send Data To a PC in LPCXpresso IDE

LPC1343 USB To Send Data To a PC

lpcware — Thu, 16 Jun 2016 02:22:41 GMT

Content originally posted in LPCWare by rtos on Sun Feb 20 10:25:00 MST 2011
I currently use an FTDI FT232R chip attached to the LPC1343 to send serial data to a PC over USB.

Can I eliminate the FTD232R chip and use the LPC1342 in USB HID mode to achieve the same thing? I don't understand enough about the different modes of USB to know if this is possible. I'm looking for some advice.

I see that I can easily hook up the USB to the LPC1343 as shown here http://ics.nxp.com/support/documents/microcontrollers/pdf/lpcxpresso.getting.started.pdf

Thanks!

Re: LPC1343 USB To Send Data To a PC

lpcware — Thu, 16 Jun 2016 02:22:41 GMT

Content originally posted in LPCWare by Ex-Zero on Sun Feb 20 11:18:27 MST 2011
1. Add USB hardware:

Schematic:
http://knowledgebase.nxp.trimm.net/showthread.php?t=505

http://knowledgebase.nxp.com/showthread.php?t=526

2. Import usbcdc example from examples.lpc13xx.new.zip

3. Read 'readme.txt' in usbcdc folder

Re: LPC1343 USB To Send Data To a PC

lpcware — Thu, 16 Jun 2016 02:22:42 GMT

Content originally posted in LPCWare by rtos on Sun Feb 20 13:17:11 MST 2011
Zero, you should change your name to Hero! Thanks for you help.

I read the posts you linked to and I need some time to digest your USB circuit as compared to the USB circuit recommended in the NXP Getting Started Guide.

I have a few questions so far.
1) EDIT: <Delete Question #1 per my next post>
2) Why would you want to connect/disconnect the 1.5K pullup resistor via software. Do you disconnect and connect the 1.5K pullup to signal to the PC that the device has been disconnected and then reconnected?

Re: LPC1343 USB To Send Data To a PC

lpcware — Thu, 16 Jun 2016 02:22:43 GMT

Content originally posted in LPCWare by rtos on Sun Feb 20 13:32:05 MST 2011
Disregard Question #1 in my previous post. The ground is connected between the LPC1343 and the USB cable. My PDF reader (Foxit Reader) was not showing the line connecting the two on my screen. I can see that the line was there when I printed it out. Very strange. I'm going to delete that question from the previous post so it does not confuse someone later.

Re: LPC1343 USB To Send Data To a PC

lpcware — Thu, 16 Jun 2016 02:22:43 GMT

Content originally posted in LPCWare by Ex-Zero on Sun Feb 20 13:40:42 MST 2011
1. Yes!! No Ground, no Fun :)

2. AFAIR working without FET requires a lot disconnecting and reconnecting...

User manual:

5.6 SoftConnect
The connection to the USB is accomplished by bringing USB_DP (for a full-speed device) HIGH through a 1.5 kOhm pull-up resistor. The SoftConnect feature can be used to allow software to finish its initialization sequence before deciding to establish connection to the USB. Re-initialization of the USB bus connection can also be performed without having to unplug the cable.