Zhiyong Li

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10 years, 8 months ago.

How to access all pins on Mbed LPC1768?

Hi folks,

I am building my customized board with LPC1768. Because I have quite a few peripherals, I will need to repurpose the ethernet phy pins to GPIO and probably some other unexposed pins on mbed. Could some body tell me whether this is possible?

I am still in the middle of building circuit and haven't done any actual code in mbed yet. I may have stumbled onto some post on this topic but I could not find it later on. So please forgive me if this question has been asked and answered before.

Thanks in advance,

ZL

1 Answer

Erik -
10 years, 8 months ago.

Yep, you can address all pins as Px_#, for example P0_1 for port 0, pin 1.

Accepted Answer

I dont quite understand; the 1768 has no ports, just pXX as pin numbers to associate to GPIO. How do we access the ethernet pins named: RD-, RD+, TD-, TD+, to make them a DigitalOut or DigitalIn?

Thanks

posted by Ethan P 27 Aug 2014

It has ports, just not as standard pin numbers. But you cannot use the ethernet pins as GPIO pins.

posted by Erik - 28 Aug 2014

Thanks. The post above led me to believe I can repurpose the ethernet pins as GPIO

posted by Ethan P 28 Aug 2014

He has a custom board, so I assumed he meant the mbed pins connected to the ethernet PHY, not the ethernet PHY pins connected to the physical pins on the default mbed. That indeed is not possible.

IIRC D+ and D- can be used as GPIO, but you need to search their port/pin number.

posted by Erik - 28 Aug 2014

Ah, that will help. Thanks

posted by Ethan P 28 Aug 2014