I'm not officially lost!
Ive got a AD5235(http://www.analog.com/static/imported-files/data_sheets/AD5235.pdf ) for replacing the volume dial in my audio amplifier.
I've got the thing wired up and coded as per this tut - http://www.arduino.cc/en/Tutorial/SPIDigitalPot#.UwdMqHna7wN - but it doesn't work. I see no change on the wiper reading.
I've tried using this one as well - http://www.reigndesign.com/blog/controlling-a-10-bit-digital-potentiometer-via-spi-with-arduino/
And, I've also tried this replicating this once - http://forum.arduino.cc/index.php/topic,85837.0.html
All to no avail.
This is all part of a home cinema project, and everything else is working bar this last bit.
Can someone offer me some support?
Thanks
Martin
knut_ny
February 21, 2014, 10:56pm
2
pin 10 , SS defined OUTPUT ??
all connection cables OK ?
spi-mode ? , msb/lsb first ?
pullups needed ?
no mods in transfer speed
if it still doesnt work. hardware has faults. use scope to check signals
Im just going to get the breadboard back out and try it again.
Ive got a Pro Mini, could you quickly run up the config you would use for the rest of the pin configuration.
knut_ny
February 22, 2014, 1:37pm
4
I'v seen the datasheet. Not sure, but from what I can see(read) I hope somethine near this can do.have to be stored in chip..
/* interfacing AD5235, digital pot
Arduino pin AD5235
D10 (CS) CS (pin 15)
D11 (MOsi) Din (pin 2)
D12 (MIso) Do (pin 3)
D13 (Clk) Clk (pin 1)
GND GND (pin 4),Vss (pin 5)
5V Vdd (pin 12),wp(13),pr(14)
--------------
Wiper1: pins 6, 7, 8
Wiper2: pins 11,10, 9
no connect RDY pin 16
ADDR (wiper1) = 0
ADDR (wiper2) = 1
*/
#include <SPI.h>
byte cs = 10;
byte wip1=0;
void setup()
{
SPI.begin();
SPI.setBitOrder(MSBFIRST); //We know this from the Data Sheet
// 24bits must be sent
pinMode(cs,OUTPUT);
digitalWrite(cs,HIGH);
}
void loop()
{
// test: set incr. position 0..1020 step 15
for (int i=0; i<1024; i+=15)
{
setvol(0,i); //wiper,volume
delay(100);
}
}
void setvol(byte wiper, int value) // wiper MUST be 0 or 1
{
digitalWrite(cs, LOW); //select potmeter
byte command = 0xB0 || wiper;
byte hibyte = highByte(value);
byte lowbyte = lowByte(value);
SPI.transfer(command);
SPI.transfer(byte1);
SPI.transfer(byte0);
digitalWrite(cs, HIGH);
// may remove nxt 5 lines: (stores this setting to eeprom)
digitalWrite(cs, LOW); //select potmeter
SPI.transfer(0x20 || wiper);
SPI.transfer(0);
SPI.transfer(0);
digitalWrite(cs, HIGH);
}