Help with Absolute encoder 14 bit

Projects Programming
1

I've got an absolute encoder with chip MLX90363 SPI ,14 bit output, .
Now I've got a code in C which works on mbed but i need to run it in arduino
I have attached the code here,i want to convert it to its arduino equivalent

I am a beginner in arduino. Can someome please help me to understand the code and to convert it in arduino...?! Thank you.

#include "mbed.h" 
SPI spi(p5, p6, p7); //MOSI, MISO, CLK 
DigitalOut ss1(p8); //SS Pin for Die 1 
Serial pc(USBTX, USBRX); //Create a virtual serial port 
int main(void) { 
char u8_spi_mode = 1; //SPI mode 
char u8_spi_bits = 8; //number of bits per mbed write command 
char u8_spi_read_buffer[8]; 
char u8_spi_write_buffer[8]; 
float f32_angle_degrees; 
unsigned int u16_angle_lsb; 
char u8_error_lsb; 

//360 degrees is mapped to 14 bits = 360/2^14 = 0.02197 
const float f32_lsb_to_dec_degrees = 0.02197; 
//Serial port setup 
pc.baud(115200); 
//SPI Bus setup 
spi.format(u8_spi_bits, u8_spi_mode); 
spi.frequency(500000); 
ss1 = 1; //SS to deselected state 
while (1){ 
//issue GET1 message 
u8_spi_write_buffer[0] = 0x00; 
u8_spi_write_buffer[1] = 0x00; 
u8_spi_write_buffer[2] = 0xFF; 
u8_spi_write_buffer[3] = 0xFF; 
u8_spi_write_buffer[4] = 0x00; 
u8_spi_write_buffer[5] = 0x00; 
u8_spi_write_buffer[6] = 0x13; 
u8_spi_write_buffer[7] = 0xEA; 
ss1 = 0; 
for (int i = 0; i < 8; i++){ 
u8_spi_read_buffer[i] = spi.write(u8_spi_write_buffer[i]); 
} 
ss1 = 1; 
wait_ms(1); 
//issue NOP message 
u8_spi_write_buffer[0] = 0x00; 
u8_spi_write_buffer[1] = 0x00; 
u8_spi_write_buffer[2] = 0xAA; 
u8_spi_write_buffer[3] = 0xAA;
u8_spi_write_buffer[4] = 0x00; 
u8_spi_write_buffer[5] = 0x00; 
u8_spi_write_buffer[6] = 0xD0; 
u8_spi_write_buffer[7] = 0xAB; 
ss1 = 0; 
for (int i = 0; i < 8; i++){ 
u8_spi_read_buffer[i] = spi.write(u8_spi_write_buffer[i]); 
} 
ss1 = 1; 
//Extract and convert the angle to degrees 
//remove error bits and shift to high byte 
u16_angle_lsb = (u8_spi_read_buffer[1] & 0x3F) << 8; 
//add LSB of angle 
u16_angle_lsb = u16_angle_lsb + u8_spi_read_buffer[0]; 
//convert to decimal degrees 
f32_angle_degrees = u16_angle_lsb * f32_lsb_to_dec_degrees; 
//Extract the error bits 
u8_error_lsb = u8_spi_read_buffer[1] >> 6; 
//Send results to serial port 
pc.printf("Angle (LSb): %d\r\n", u16_angle_lsb); 
pc.printf("Angle (Dec): %2.2f\r\n", f32_angle_degrees); 
pc.printf("Error Bits (Dec): %d\r\n", u8_error_lsb); 
wait(0.5);
}
}

mlx90363-datasheet-melexis.pdf (1.13 MB)

2

Kkksc:
Now I've got a code in C which works on mbed but i need to run it in arduino .

SPI spi(p5, p6, p7); //MOSI, MISO, CLK

DigitalOut ss1(p8); //SS Pin for Die 1
Serial pc(USBTX, USBRX); //Create a virtual serial port

[...]

//Serial port setup
pc.baud(115200);
//SPI Bus setup
spi.format(u8_spi_bits, u8_spi_mode);
spi.frequency(500000);

I'm pretty sure that's C++, not C.

What have you tried?
The main difference are the Serial and SPI APIs, which are well-documented in the Arduino references. The rest should remain mostly the same.

Pieter

3

One other difference: You should change the variables whose name start with 'u8' from 'char' to 'byte'. Otherwise you will get sign extension when you shift the values to the right.