In the handbook the partial schematics of the mbed NXP LPC1768 Microcontroller are published as PDF, with the mbed interface subsystem removed.
So that there is a place to start from for new projects, here are the schematics, Eagle libraries. I would also like to build up a BOM of this that anyone can update with part numbers from thier favourite vendor.
A few notes:
The first page of the Eagle schematics are blank intentionally. If you are using thefree version this is the only page you can edit
The R'c and C's are generic, and there are multiple footprints for each. You should therefore be able to make this through hole or SMD without changing the schematics
why did you put 10 kOhm pulldowns on TXD0 and RXD0 (TGT_SBL_TXD and TGT_SBL_RXD) in your reference design? Is there a specific recommendation for that?
I have also a question regarding the JTAG-Pins. When the JTAG-Interface is not used, can i leave the corresponding pins open or do i have to implement the pullups and -downs like in your refdesign (or could i even directly tie them to VDD or GND accordingly)?
Best regards
Nenad
Hi Christian,
why did you put 10 kOhm pulldowns on TXD0 and RXD0 (TGT_SBL_TXD and TGT_SBL_RXD) in your reference design? Is there a specific recommendation for that?
I have also a question regarding the JTAG-Pins. When the JTAG-Interface is not used, can i leave the corresponding pins open or do i have to implement the pullups and -downs like in your refdesign (or could i even directly tie them to VDD or GND accordingly)?
Best regards
Nenad
The LPC1768 User guide seems to indicate that the ISP pin should be pulled up, which is not done in the current schematic (it was on the original mbed design). Also it looks like the FTDI header is hooked up wrong, TX and RX should be crossed over. Finally, don't use Sparkfun's version of FTDI cables with this design since they have RX/TX pulled up while this design has them pulled down (but official FTDI cables should work OK). User beware.
The LPC1768 User guide seems to indicate that the ISP pin should be pulled up, which is not done in the current schematic (it was on the original mbed design). Also it looks like the FTDI header is hooked up wrong, TX and RX should be crossed over. Finally, don't use Sparkfun's version of FTDI cables with this design since they have RX/TX pulled up while this design has them pulled down (but official FTDI cables should work OK). User beware.
Has anybody got the USB connection working? Hooking a connector to the mbed device and running my program, the computer recognises and correctly enumerates the mbed as a USBMIDI port. The exact same program, uploaded to an lpc1768 on my target board, however, elicits a "USB Device Not Recognized" pop-up on the pc. Has anyone else experienced similar problems?
problem solved
Thanks,
James
--Has anybody got the USB connection working? Hooking a connector to the mbed device and running my program, the computer recognises and correctly enumerates the mbed as a USBMIDI port. The exact same program, uploaded to an lpc1768 on my target board, however, elicits a "USB Device Not Recognized" pop-up on the pc. Has anyone else experienced similar problems?--
problem solved
Thanks,
James
I've just updated the PDF of the schematic, and the zip file with the Eagle files. The changes are :
- Added a pull up to the ISP line on the target
- Removed the pull down resistors on the Serial port
- Corrected the TX/RX lines on the FTDI header.
Anything else I've missed, please let me know!
Cheers,
Chris
Hi All,
Thanks for all the feedback and bug reports.
I've just updated the PDF of the schematic, and the zip file with the Eagle files. The changes are :
- Added a pull up to the ISP line on the target
- Removed the pull down resistors on the Serial port
- Corrected the TX/RX lines on the FTDI header.
Anything else I've missed, please let me know!
Cheers,
Chris
In the design IC3 MBED_MICROCONTROLLER - Where are the specs? where can I get it? And I do not require Ethernet in my design, so is there a need to put the DP83848J IC TXRX ETHERNET PHYTER 40-LLP on the board? Thank you very much in advance for your answers.
Regards
Victor
Hi All,
In the design IC3 MBED_MICROCONTROLLER - Where are the specs? where can I get it? And I do not require Ethernet in my design, so is there a need to put the DP83848J IC TXRX ETHERNET PHYTER 40-LLP on the board? Thank you very much in advance for your answers.
Regards
--Victor
Hi. tanks for the schematics, i´m desing a PCB for periferics compatibles and when i finish it, i show you and can compart ok.... bye and tanks you so much!!!...
Sorry for my english, not is good because my native languaje is Spanish, i´m of Ecuador....
/-----------------------------/*
Hola, muchas gracias por los esquematicos, yo estoy diseñando un PCB para los perifericos compatibles y cuando la finalice yo la mostrare a ustedes y podremos compartirla, muchisimas gracias y hasta la vista...
Disculpas por mi ingles, no es bueno porque mi idioma nativo es Español, yo soy de Ecuador...
Hi. tanks for the schematics, i´m desing a PCB for periferics compatibles and when i finish it, i show you and can compart ok.... bye and tanks you so much!!!...
Sorry for my english, not is good because my native languaje is Spanish, i´m of Ecuador....
*/-------------------------------------------------------------------------------------------------------------------------------------------------/*
Hola, muchas gracias por los esquematicos, yo estoy diseñando un PCB para los perifericos compatibles y cuando la finalice yo la mostrare a ustedes y podremos compartirla, muchisimas gracias y hasta la vista...
Disculpas por mi ingles, no es bueno porque mi idioma nativo es Español, yo soy de Ecuador...
Hello Experts,
I copy the reference design to eagle and start to work on it. In the mbed refdesign schematic there are some libraries used like mbed-connectors. If you make a board from this schematic the usb connector is changed to pinhead connector. Where can I get the missing libraries?
Regards Marc
Hello Experts,
I copy the reference design to eagle and start to work on it. In the mbed refdesign schematic there are some libraries used like mbed-connectors. If you make a board from this schematic the usb connector is changed to pinhead connector. Where can I get the missing libraries?
Regards Marc
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