Compiler/MSP430G2210: MSP430G2210 comparator functioning

Robert Verhulst

Part Number: MSP430G2210

Tool/software: TI C/C++ Compiler

Hello, can somebody help me ?

I’m using the MSP430G2210 and have to detect a voltage superior of 0.25xVcc on pin 4 (P1.6) and give a high output on pin 5 (P1.7) when this is the case.

I’ve used following settings :
P1REN=0x1B; // Terminate unavailable Port1 pins (P1.0/1/3/4) properly
P1DIR= 0x80; // my output

CACTL1=CAREF0 | CAON | CAEX;

CACTL2=P2CA3|P2CA2

With my program I would like to activate my output whenever I test CAOUT==0, but CAOUT stays==1?

Thanks for any help

Robert

over 4 years ago

0 Bruce McKenney47378 over 4 years ago

Guru 88700 points

Are you checking CAOUT in the register or at the pin? Per data sheet (SLAS753E) Table 16, you should set P1SEL.7=1 to get output at the pin.

Also, you should set CAPD.6=1 to make P1.6 act like a real analog input [Also Table 16].

0 Robert Verhulst over 4 years ago in reply to Bruce McKenney47378

Prodigy 150 points

Bruce,

I check CAOUT with an if (CAOUT) statement in c programming

I'm using an IAR workbench to compile and load but P1SEL.7 and CAPD.6 are unknown for the compiler.

In fact I worked on bases of an example program msp430g2210_ca_04.c in the example library put using other pins.

0 Bruce McKenney47378 over 4 years ago in reply to Robert Verhulst

Guru 88700 points

You would set those bits using:

> P1SEL |= BIT7; // P1SEL.7=1 -> P1.7 as CAOUT per data sheet Table 16

> CAPD |= BIT6; // CAPD.6=1 -> P1.6 as CA6 per data sheet Table 16

I also find it a little odd that the examples don't set CAPD. The pin schematic (data sheet Figure 22) makes it look pretty important.

In case it needs to be said: CAOUT is a constant (==1). Test it using "if (CACTL2 & CAOUT)".

0 Robert Verhulst over 4 years ago in reply to Bruce McKenney47378

Prodigy 150 points

Super many thanks Bruce

This works !

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Compiler/MSP430G2210: MSP430G2210 comparator functioning