MSP430F5529: Is it proper to continuously switch a GPIO Direction (I/p to O/p and vice versa) at a rate of 1 ms ?

Shubhendra Singh

Part Number: MSP430F5529

hello every one ,

i want to interface a push button Switch and LED on same GPIO. i have already built the circuit and successfully interfaced both switch and LED on same pin. Now I have one question is it fine to change direction register of controller continuously [ from internal hardware point of view ].

i am using pin5 of port 7 in 430F5529.

over 8 years ago

0 Agustin Villavedra over 8 years ago

Intellectual 510 points

Hello,
Switching direction shouldn't be a problem. Be careful not to short the output, and you might need to use delays to read the input and not your output.
It does not sound right from a hardware view....at least not the easiest

0 Ilmars over 8 years ago in reply to Agustin Villavedra

Guru 46710 points

Agustin Villavedra said:
It does not sound right from a hardware view....at least not the easiest

It does sound right indeed. GPIO is made to support bidirectional mode, for example in case of one wire bus. Adding delay after direction change is very good advice.

0 Keith Barkley over 8 years ago

Guru 42145 points

As everyone said, no problem, the typical sonars need to do this.

0 Agustin Villavedra over 8 years ago in reply to Ilmars

Intellectual 510 points

I meant multiplexing a LED and a switch. The GPIO should work fine.

0 Shubhendra Singh over 8 years ago in reply to Agustin Villavedra

Intellectual 885 points

hi everyone,
thanks for replying, at starting i was also concerned about shorting of the output but i have already taken care of that part.
i have designed external circuit in such a way that if GPIO is in output mode and my switch is pressed it will not short it to ground. i had already checked this part every thing is working fine.
actually i was worried from controller point of view and i think i got my answer.
thanks every one

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MSP430F5529: Is it proper to continuously switch a GPIO Direction (I/p to O/p and vice versa) at a rate of 1 ms ?