16F15345 DAC don't work [Solved]

[Roberto da Rivoli]

#include <main.h>

void main()
{

while(TRUE)
{

setup_DAC(DAC_VSS_VDD | DAC_OUTPUT);
dac_write(25); // OV DRL-->OFF
delay_ms(1000);
setup_DAC(DAC_VSS_VDD | DAC_OUTPUT);
dac_write(10); // OV DRL-->OFF
//TODO: User Code
}

}

[Ttelmah]

Comments:

First, learn to use the code buttons.
Then the code should be something we can compile. So you need to include
the stuff in main.h
Now with those said:

[Roberto da Rivoli]

thanks Ttelmah
I apologize if I was not very clear, and I entered a really badly written piece of code, but the whole project is very complex and needs some elaborate hardware behind it.

I inserted the two lines you recommended and now it works
#BYTE ANSELA = getenv ("SFR: ANSELA")
bit_set (ANSELA, 0); // turn on ANSEL bit for DAC1OUT1

I did not know I had to enter this code, on other micro I had not done it.
Thanks for the support

[Ttelmah]

OK. That makes sense then.

Mark the thread as [solved].

The point about ANSEL, is it doesn't exist, except on relatively new 'low
power' chips. It turns off the digital connection to a pin. Needs to be enabled
on things like ADC inputs, the DAC output, inputs to the comparators etc..
You need to set it on for every pin used for analog.
Though it is described as turning off the digital connection (which would
only be to save power), on some chips it seems to actually disconnect the
analog connection unless enabled, which is why you were having problems.
A 'caveat' on such chips...

[Ttelmah]

As one final comment, you can do this without accessing the register
yourself, by using:

set_analog_pins(PIN_A0);

This historically had issues on some chips (which is why I went manual),
but on recent compilers works fine.

[Roberto da Rivoli]