PIC16F1778 10-bit DAC, anyone?

[Mike]

I'm trying to get the 10-bit DAC of the PIC16F1778 working and am not being successful.  Has anyone used this, or similar?  I'm scoping the output pin and getting nothing.  Below is my code.  Any push in the right direction is appreciated.

Regards,

Mike

--

include 16f1778                     -- target PICmicro

--

pragma target clock    8_000_000       -- oscillator frequency

--

pragma target OSC      INTOSC_NOCLKOUT           -- internal oscillator

pragma target PLLEN    DISABLED                  -- PLL off

pragma target CLKOUTEN DISABLED                  -- no clock output

pragma target WDT      DISABLED                  -- watchdog off

pragma target BROWNOUT DISABLED                  -- no brownout reset

pragma target FCMEN    DISABLED                  -- no clock monitoring

pragma target IESO     DISABLED                  -- no int/ext osc switching

pragma target LVP      DISABLED                  -- low voltage programming off

pragma target MCLR     INTERNAL                  -- internal reset

--

--

OSCCON_SCS = 0                      -- select primary oscillator

OSCCON_IRCF = 0b1110                -- 8 MHz

OSCCON_SPLLEN = FALSE               -- software PLL off

--

enable_digital_io()                 -- make all pins digital I/O

--

LATA = 0

LATB = 0

LATC = 0

TRISA = 0

TRISB = 0

TRISC = 0

DAC1REFL = 0

DAC1REFH = 0

DAC1CON0 = 0b1010_0000 -- DAC on and output to the pin

--

var byte c = 0

--

forever loop

for 255 using c loop

    DAC1REFL = c

    DACLD_DAC1LD = true

    _usec_delay(100_000)

end loop

end loop

--

[Mike]

Well, I got it working, but I'm not sure what I did.  Needs some more research.

Regards,

Mike

[Mike]

By the way, this 10-bit DAC could be very nice for audio applications.  And this PIC16F1778 also has an op-amp.  If I get something interesting working I'll post it.

Regards,

Mike

[Rob CJ]

Hi Mike,

I used a 10-bit DAC with PIC16F1765 in my Digital Controlled Power Supply:

Digital Controlled Linear Power Supply : 6 Steps (with Pictures) - Instructables

I used two functions.

; Initialize the 10-bit Digital to Analog Converter (DAC)

procedure dac_init() is

   ; Enable, right justified, output enable, use VDD as reference, VRef- to VSS.

    DAC1CON0 = 0b1010_0000 ; VDD reference.

    dac_set(MIN_DAC_VALUE) ; Output at minimum    

end procedure

; Write the given value to the 10-bit DAC.

procedure dac_set(word in value) is

   DAC1REF = value

   DACLD_DAC1LD = TRUE

   while DACLD_DAC1LD loop

      ; Wait for DAC to complete transfer.

   end loop

end procedure

This was a very fruitful project for JAL since I extracted two JAL libraries from it, one to control a digital potentiometer and one to write data into HEF (this PIC does not have EEPROM but HEF instead) 😊

Hope this helps.

Kind regards,

Rob

---

Van: 'Mike' via jallib <jal...@googlegroups.com>
Verzonden: zaterdag 28 november 2020 03:37
Aan: jallib <jal...@googlegroups.com>
Onderwerp: [jallib] PIC16F1778 10-bit DAC, anyone?

 

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[vsurducan]

Hi Rob,

Which is the meaning of the word "ROJA" ? :)

thx,

Vasile

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[Rob CJ]

Haha,

ROb JAnsen 😊

Kind regards,

Rob

---

Van: jal...@googlegroups.com <jal...@googlegroups.com> namens vsurducan <vsur...@gmail.com>
Verzonden: zaterdag 28 november 2020 08:07
Aan: jal...@googlegroups.com <jal...@googlegroups.com>
Onderwerp: Re: [jallib] PIC16F1778 10-bit DAC, anyone?

 

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[Mike]

Hi Rob,

Thank you for posting that.  I'll definitely take a look at it.

Regards,

Mike