MSP430G2553: Issue with SPI, problem may be in the code.

Hi Edoardo,
Can you please post a scope shot and your code, and perhaps a schematic?

I'll look over it and help you find the root of your problem.

Sorry I changed a few things. I wrote the code for the accelerometer (using Energia) but still it is not working. Basically it shows the x y and z values as either 0's or -1's and no other changes. From the comments at the beginning of the code and the schematics in the two links below you can see the connections I made.

www.google.co.uk/url

www.st.com/.../en.steval-mki135v1_schematic.pdf


#include <SPI.h>

/*
#define DATAOUT 15 //MOSI MSP430G2553 pin 15; LIS2DH SDI pin21
#define DATAIN 14 //MISO MSP430G2553 pin12; LIS2DH SDO pin22
#define SPICLOCK 13 //SCK MSP430G2553 pin 7; LIS2DH SCL pin20
#define cs 8 //CS pin 8; cs LIS2DH pin19, active low, 0: SPI enabled
*/

//Register Addresses:
const int OUT_X_L = 0x28; //X-axis acceleration data
const int OUT_X_H = 0x29;
const int OUT_Y_L = 0x2A; //Y-axis acceleration data
const int OUT_Y_H = 0x2B;
const int OUT_Z_L = 0x2C; //Z-axis acceleration data
const int OUT_Z_H = 0x2D;

int CS = 8;

int readRegister(byte x) {
int r=0;
byte b = x| (0b10000000);

digitalWrite (CS, LOW);
SPI.transfer(b);
r = SPI.transfer (0x00);
digitalWrite (CS, HIGH);
return r;
}


int readval (int x) {
int val;
byte h, l;

if (x==1) {
l = readRegister(OUT_X_L);
h = readRegister(OUT_X_H);
}
else if (x == 2) {
l = readRegister(OUT_Y_L);
h = readRegister(OUT_Y_H);
}
else if (x == 3) {
l = readRegister(OUT_Z_L);
h = readRegister(OUT_Z_H);
}
val = (h<<8) | l;
return val;
}


void setup()
{
delay(500);
pinMode(CS,OUTPUT);

SPI.begin();
//our device requires data to be sent MSB
//(most significant byte) first, pg. 23
SPI.setBitOrder(MSBFIRST);
//clock is idle high and data is shifted in and out
//on the rising edge of the data clock signal, pg. 23
SPI.setDataMode(SPI_MODE3);
SPI.setClockDivider(SPI_CLOCK_DIV2);
//Create a serial connection to display the data on the terminal.
Serial.begin(9600);
delay(500);
}

void loop()
{
Serial.print(" x = ");
Serial.print(readval(1));
Serial.print(" y = ");
Serial.print(readval(2));
Serial.print(" z = ");
Serial.println(readval(3));
delay (500);

}

Using a scope, are you seeing a clock on the SCK line? I see that you have selected pin 13 in your code, but if I'm not mistaken, the energia library uses pin 13 for the SCK.

Are you seeing any data on the MISO and MOSI lines? If so, what data and on which lines?

I don't see a clk and no data in MISO and MOSI.
I connected the SCK to pin 7 (P 1.5) according to this.
energia.nu/.../

Any idea of what the problem might be?

Kind regards
Edoardo Occhipinti