Pull Down register enable

vikas dabas

Intellectual 670 points

Taking ADC i/p at P1.1

P1OUT |= 0X02;

P1REN &= ~0X02; // Enable pull down register

Vcc =3.58v

AT P1.1 Vcc = 3.52v.

I don't get low signal here.

over 12 years ago

0 Robert Cowsill over 12 years ago

Guru 16361 points

P1REN &= ~0X02 disables the pull-up/down resistor on p1.1. If you want to enable pull-down on p1.1 you need to do this:

P1REN |= 0X02;  // Enable resistor on P1.1
P1OUT &= ~0X02; // Set P1.1 resistor to pull down

Notice that when a bit in PxREN is set, the matching bit of PxOUT sets whether the resistor is pulling up or down. This is detailed in section 8.2.4 of the MSP430x2xx Family User's Guide.

0 vikas dabas over 12 years ago in reply to Robert Cowsill

Intellectual 670 points

Sorry Bro. I'm still getting 2.5v supply

Try for single pin and double pins. It shows same 2.5v each pin

0 Robert Cowsill over 12 years ago in reply to vikas dabas

Guru 16361 points

Is this on a launchpad? If so, do you have the TXD/RXD jumpers in place on J3?

0 vikas dabas over 12 years ago in reply to Robert Cowsill

Intellectual 670 points

Yes it is msp430g2 launchpad.

All Jumpers of J3 are connected in parallel.

0 vikas dabas over 12 years ago in reply to vikas dabas

Intellectual 670 points

After some experiments, Failures, And hit.....

I've tried to remove the RXD and TXD from J3 and now all pull down and pull up works.

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Pull Down register enable