Hi
Just starting my attempt at reading a sensor through SPI. So I wrote this skeleton code that errors out when I try to compile.
"ss1" was not declared in this scope
In the setup I did declare a "const int ss1", used it as "ss1" to set pinmode and wrote it high( just to be sure to be sure 
)
That work fine but when I use "ss1" in the loop it errors out.
What am I missing here?
I did google and searched forum, this seems to be way its done: declare it in set up, then use in remainder of code.
Note:
I commented out the line: digitalWrite (ss1,LOW); The line that errors out in loop
then the next variable "Ang_ss1" errors out.
Declarations in setup does not work in main loop?
/* ******************************************************************************
* SPI read 3x A1335 rotation sensor chips with UNO and display on serial monitor
* Slave select pins 10 >ss1, 9 >ss2, 8 >ss3
*/
#include <SPI.h>
void setup() {
// set slave pins and variables
const int ss1 = 10;
const int ss2 = 9;
const int ss3 = 8;
int Ang_ss1 = 0;
int Ang_ss2 = 0;
int Ang_ss3 = 0;
//set slave pins High and as outputs
pinMode (ss1,OUTPUT);
digitalWrite (ss1,HIGH);
pinMode (ss2,OUTPUT);
digitalWrite (ss2,HIGH);
pinMode (ss3,OUTPUT);
digitalWrite (ss3,HIGH);
SPI.begin();
Serial.begin(9600);
}
void loop() {
/*SPI settings incorparated here and not declared globaly for attaching
spi devices with difrent settings. Call transaction,begin with new
settings*/
SPI.beginTransaction(SPISettings(15000000,MSBFIRST,SPI_MODE0));
//select sensor 1 to 3 and read registers 0x20 and 0x21
digitalWrite (ss1,LOW);
Ang_ss1 = SPI.transfer16(0x20);
digitalWrite (ss1,HIGH);
digitalWrite (ss2,LOW);
Ang_ss2 = SPI.transfer16(0x20);
digitalWrite (ss2,HIGH);
digitalWrite (ss3,LOW);
Ang_ss3 = SPI.transfer16(0x20);
digitalWrite (ss3.HIGH);
SPI.endTransaction()
// convert received angle values to angular degrees
Serial.print(Ang_ss1*(360/4096)"DEG ");
Serial.print(Ang_ss2*(360/4096)"DEG ");
Serial.println(Ang_ss3*(360/4096)"DEG");
}
Then move declerations infront of " void set up"
Now it errors out on "digitalWrite (ss3,HIGH);" (Its happy with the same statement for previous ss2 and ss1 lines)
Expected constructor, destructor or type conversion before '('
/* ******************************************************************************
* SPI read 3x A1335 rotation sensor chips with UNO and display on serial monitor
* Slave select pins 10 >ss1, 9 >ss2, 8 >ss3
*/
#include <SPI.h>
// set slave pins and variables
const int ss1 = 10;
const int ss2 = 9;
const int ss3 = 8;
int Ang_ss1 = 0;
int Ang_ss2 = 0;
int Ang_ss3 = 0;
//set slave pins High and as outputs
pinMode (ss1,OUTPUT);
digitalWrite (ss1,HIGH);
pinMode (ss2,OUTPUT);
digitalWrite (ss2,HIGH);
pinMode (ss3,OUTPUT);
digitalWrite (ss3,HIGH);
void setup() {
SPI.begin();
Serial.begin(9600);
}
void loop() {
/*SPI settings incorparated here and not declared globaly for attaching
spi devices with difrent settings. Call transaction,begin with new
settings*/
SPI.beginTransaction(SPISettings(15000000,MSBFIRST,SPI_MODE0));
//select sensor 1 to 3 and read registers 0x20 and 0x21
digitalWrite (ss1,LOW);
Ang_ss1 = SPI.transfer16(0x20);
digitalWrite (ss1,HIGH);
digitalWrite (ss2,LOW);
Ang_ss2 = SPI.transfer16(0x20);
digitalWrite (ss2,HIGH);
digitalWrite (ss3,LOW);
Ang_ss3 = SPI.transfer16(0x20);
digitalWrite (ss3.HIGH);
SPI.endTransaction()
// convert received angle values to angular degrees
Serial.print(Ang_ss1*(360/4096)"DEG ");
Serial.print(Ang_ss2*(360/4096)"DEG ");
Serial.println(Ang_ss3*(360/4096)"DEG");
}