Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

[PIC] Interfacing AD7490 with PIC16F1789

Status
Not open for further replies.

Poochi

Newbie level 1
Joined
Jul 18, 2018
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
12
I am trying to read data from AD7490 via SPI but I keep getting FF. Can you please help me find out what is wrong with my code? The code is given below:


Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
#include <16F1789.h>
#fuses NOWDT, NOBROWNOUT, NOMCLR
#use delay(internal=8MHz, clock=8MHz)
#include <PIC16F1789_registers.h>
 
 
#use rs232(baud=9600,parity=N,xmit=PIN_B6,rcv=PIN_B7,bits=8,stream=PORT1)
 
#use spi(MASTER, CLK = PIN_C3, DI = PIN_C4, DO = PIN_C5, BAUD = 9600, BITS = 16, STREAM = PORT2, MODE = 2 )
 
 
void main()
{
 
TRISC2 = 0;
 
 
 
   while(True)
   {
   
         RC2 = 0;
         ////////////////////////////////////////////
         spi_write(PORT2, 0xAB);
         spi_write(PORT2, 0x30);
         
          RC2 = 1;
          delay_us(5);
          
          RC2 = 0;
         
         
         spi_write(PORT2, 0x00);
         spi_write(PORT2, 0x00);
         
         delay_us(5);
         
              
         int16 vol_X = spi_xfer(PORT2);
         
        
        
         /////////////////////////////////////////////
         RC2 = 1;
 
 
         fputc(vol_X, PORT1);
          
         delay_ms(500);
   
  
   }
 
 
}

 
Last edited by a moderator:

Hmmm, not familiar with code syntax, but I think you try to make single conversions of Vin10.
checkout the sequence described in datasheet, the conversion output is interleaved, so you need one dummy write in front:


Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
void main()
{
  // Setup
  TRISC2 = 0;
  RC2 = 1;
  delay_us(5);
 
  // Dummy write to trigger first conversion - data read is ignored
  RC2 = 0;
  // not sure if Port2 is 8 or 16 bit register, maybe try spi_write(PORT2, 0xAB30)
  spi_write(PORT2, 0xAB);
  spi_write(PORT2, 0x30);
  RC2 = 1;
  delay_ms(500);
 
  while(True)
  {
    // write to trigger next conversion - data read is result from previous write
    RC2 = 0;
    // not sure if Port2 is 8 or 16 bit register, maybe try spi_write(PORT2, 0xAB30)
    spi_write(PORT2, 0xAB);
    spi_write(PORT2, 0x30);
    RC2 = 1;
    
    int16 vol_X = spi_xfer(PORT2);
    
    // Output read data to UART
    fputc(vol_X, PORT1);
    delay_ms(500);
  }
}

 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top