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scanan
Joined: 13 Aug 2004
Posts: 58
Location: Turkey
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| About MAX528/529 driver |
 Posted: Tue Jul 10, 2012 12:13 am |
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Hi,
I wonder if someone has written a driver for the MAX528 Octal DAC.
cheers |
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temtronic
Joined: 01 Jul 2010
Posts: 9162
Location: Greensville,Ontario
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| Posted: Wed Jul 11, 2012 7:15 pm |
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Just printout the datasheet, google 'max528 CCS C code'...see what comes up, try your hand at cutting the code. Also check similar 'family' type parts, say a quad DAC or dual DAC, it may be very, very similar.
Drivers are not magical...just common sense, line by line coding.
Take a stab at it, upload here so we can see how you're doing so we can 'fill in the blanks'.
I don't cut code without real parts on a breadboard to test as it's the ONLY way to verify the code does work.
Most datasheets will tell you 99% of what you have to know to get the product up and running, the other 1% deals with board layout, wiring, EMI,e tc.
hth
jay |
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scanan
Joined: 13 Aug 2004
Posts: 58
Location: Turkey
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| Posted: Wed Mar 26, 2014 9:15 am |
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| Code: | void max528(unsigned int8 chan,unsigned int8 value)
{
unsigned int8 data;
#bit dataMSBit=data.7;
/////////// zero all DAC output
output_high(PIN_D7);
output_low(PIN_D7);
for(m=0;m<25;m++){};
output_low(PIN_C3);
data=chan;
for(jj=0;jj<8;jj++){
output_low(PIN_C3);
output_bit(PIN_C4,dataMSBit);
for(m=0;m<25;m++){};
output_high(PIN_C3);
for(m=0;m<25;m++){};
data<<=1;
}
data=value;
for(jj=0;jj<8;jj++){
output_low(PIN_C3);
output_bit(PIN_C4,dataMSBit);
for(m=0;m<25;m++){};
output_high(PIN_C3);
for(m=0;m<25;m++){};
data<<=1;
}
output_high(PIN_D7);
output_low(PIN_C3);
} |
_________________
Dr Suleyman CANAN
R&D Electronic Engineer
https://suleymancanan.wordpress.com
Do whatever you do with amateur spirit -
But always feel professional. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Mar 26, 2014 5:06 pm |
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This is an SPI chip. You should be using either setup_spi() and spi_write()
or the other method, with #use spi() and spi_xfer(). |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19329
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| Posted: Thu Mar 27, 2014 5:37 am |
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No guarantees, haven't got this chip to try.
However attached is a demo program and a concept driver:
main.c
| Code: |
#include <18F4520.h> //change to suit your chip
#device ADC=10
#FUSES NOWDT //No Watch Dog Timer
#FUSES BROWNOUT //Brownout enabled
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOXINST //Extended set extension and Indexed Addressing mode disabled
#use delay(crystal=10000000)
#use rs232(baud=9600,parity=N,UART1,bits=8,errors)
#define SSP_BAUD 2000000
//define this to suit the hardware Max 4.7Mhz with 1KR pull-up. See data sheet
//define the pins used for the SSP connection to max528/9
#define SSP_1
//Define this to use hardware SSP. SSP_1 or SSP_2.
//To use software SSP
//REM this out, and define pin numbers below
#define SSP_DO PIN_xx
#define SSP_DI PIN_xx
#define SSP_CLK PIN_xx
//define the CS pin here
#define SSP_CS PIN_A0
#include <max529.h> //include the driver
void main()
{
int16 dac_val;
setup_buffers(BUFF_01 | BUFF_23 | BUFF_45 | BUFF_67 | BUFF_FULL_0TO3 | BUFF_FULL_4TO7);
//enable full buffering on all channels - change as needed
while(TRUE)
{
for (dac_val=0;dac_val<256;dac_val++)
{
//count through all possible values (sawtooth waveform)
//output inverse waveform on channels 4 to 7, and normal waveform on 0 to 3
write_dac(DAC0 | DAC1 | DAC2 | DAC3, dac_val); //writing 4 channels at once.
write_dac(DAC4 | DAC5 | DAC6 | DAC7, 255-dac_val);
//delay for a moment
delay_us(10);
}
}
}
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max529.h
| Code: |
//Driver for Max528/529 DAC
//Setup the SPI port - uses settings made in the main.
#ifdef SSP_1
#USE SPI (MASTER, SPI1, MODE=3, BITS=8, BAUD=SSP_BAUD, BITS=16, STREAM=MAX529)
#else
#ifdef SSP_2
#USE SPI (MASTER, SPI2, MODE=3, BITS=8, BAUD=SSP_BAUD, BITS=16, STREAM=MAX529)
#else
#USE SPI (MASTER, DI=SSP_DI, DO=SSP_DO, CLK=SSP_CLK, MODE=3, BITS=8, BAUD=SSP_BAUD, BITS=16, STREAM=MAX529)
#endif
#endif
//Port will tryt to use the highest rate it can below 'SSP_BAUD'. For hardware
//may get close, but software will be slower....
//defines for buffer programming
#define BUFF_01 0x20
#define BUFF_23 0x10
#define BUFF_45 0x4
#define BUFF_67 0x2 //buffer enables for channel pairs
#define BUFF_FULL_0TO3 0x8
#define BUFF_FULL_4TO7 0x1 //Enable full buffer as opposed to half buffer
//defines for DAC selection
#define DAC0 0x1
#define DAC1 0x2
#define DAC2 0x4
#define DAC3 0x8
#define DAC4 0x10
#define DAC5 0X20
#define DAC6 0x40
#define DAC7 0x80
void setup_buffers(unsigned int8 bmask)
{
unsigned int16 templ;
templ = bmask | 0x80;
output_high(SSP_CS); //ensure CS starts high
delay_cycles(1);
output_low(SSP_CS);
templ = spi_xfer(MAX529, templ, 16);
//reading the result forces transaction to complete, even if using hardware
output_high(SSP_CS);
}
void write_dac(unsigned int8 channels, unsigned int8 value)
{
//set one or more DAC channels to 'value'
int16 result;
output_low(SSP_CS); //select chip
result = spi_xfer(MAX529, make16(channels,value), 16);
output_high(SSP_CS);
}
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Completely untried, but should be pretty close. Allows you to program one or more channels at a time, and configure the buffer configuration. Demo outputs a sawtooth on four channels, and inverse sawtooth on the other four channels.
Best Wishes |
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