Microchip Starter Kits with SPI mode - c

Question

I want to use microcontrollers for communicating data by SPI. So, I have chosen firstly the Microchip USB Starter Kit III module which has a PIC32MX470F512L. I tried several ways to code its SPI, but only the clock signal SCK can be seen on an oscilloscope.
Then, i tried the same code (just adjusted a few code lines to the new PIC) with the Microchip Starter Kit I which has a PIC32MX360F512L. And all run perfectly. So, i don't understand why the USB Starter Kit III doesn't work for SPI communication?
I give you the code used to test the SPI SDO & /SS.
#define _SUPPRESS_PLIB_WARNING
#include <stdio.h>
#include <stdlib.h>
#include <plib.h>
#include <p32xxxx.h>
#include <xc.h>
#include <peripheral/spi.h>
// DEVCFG2
#pragma config FPLLIDIV = DIV_2 // PLL Input Divider (12x Divider)
#pragma config FPLLMUL = MUL_20 // PLL Multiplier (24x Multiplier)
#pragma config FPLLODIV = DIV_1 // System PLL Output Clock Divider (PLL Divide by 256)
// DEVCFG1
#pragma config FNOSC = PRIPLL // Oscillator Selection Bits (Primary Osc w/PLL (XT+,HS+,EC+PLL))
#pragma config FSOSCEN = OFF // Secondary Oscillator Enable (Disabled)
#pragma config IESO = ON // Internal/External Switch Over (Enabled)
#pragma config POSCMOD = HS // Primary Oscillator Configuration (HS osc mode)
#pragma config OSCIOFNC = OFF // CLKO Output Signal Active on the OSCO Pin (Disabled)
#pragma config FPBDIV = DIV_1 // Peripheral Clock Divisor (Pb_Clk is Sys_Clk/8)
#pragma config FCKSM = CSDCMD // Clock Switching and Monitor Selection (Clock Switch Disable, FSCM Disabled)
#pragma config WDTPS = PS1048576 // Watchdog Timer Postscaler (1:1048576)
#pragma config FWDTEN = OFF // Watchdog Timer Enable (WDT Disabled (SWDTEN Bit Controls))
// DEVCFG0
#pragma config DEBUG = OFF // Background Debugger Enable (Debugger is Enabled)
#pragma config ICESEL = ICS_PGx2 // ICE/ICD Comm Channel Select (Communicate on PGEC1/PGED1)
#pragma config PWP = OFF // Program Flash Write Protect (Disable)
#pragma config BWP = OFF // Boot Flash Write Protect bit (Protection Disabled)
#pragma config CP = OFF // Code Protect (Protection Disabled)
int main(void) {
TRISGbits.TRISG6=0; //SCK2
TRISGbits.TRISG7=1; //SDI2
TRISGbits.TRISG8=0; //SDO2
TRISGbits.TRISG9=0; //SS2
OpenSPI2(SPI_MODE16_ON|SPI_SMP_ON|MASTER_ENABLE_ON|SEC_PRESCAL_5_1|PRI_PRESCAL_16_1, SPI_ENABLE);
int data;
PORTGbits.RG9 = 1;
while(1)
{
PORTGbits.RG9 = 0;
putcSPI2(0xaaaa);
data=getcSPI2();
PORTGbits.RG9 = 1;
}
return 0;
}
Thanks

Answer 1

Pin Mapping
Do you do the pin mapping ? It does not appear on the code your posted.
You need to assign the pin to the SPI Module using the PPS (peripheral pin select).
OpenSPI is a library function, but it's also needed to do the pin mapping with the pin peripheral select (PPS)
Point 12.3.1 http://ww1.microchip.com/downloads/en/DeviceDoc/60001120F.pdf
Pin State (analog / digital)
Check your pin are not in (default) analog state. If the pin also has an analog (AN) function, the default state will be analog and you cannot control that pin. You need to set the register ANSELx (or AD1PCFG) to set the pin.
In the chip PIC32MX470F512L the pin you are using (RG6-9) also has analog function (AN):
10 AN16/C1IND/RPG6/SCK2/PMA5/RG6
11 AN17/C1INC/RPG7/PMA4/RG7
12 AN18/C2IND/RPG8/PMA3/RG8
14 AN19/C2INC/RPG9/PMA2/RG9
Page 7 http://ww1.microchip.com/downloads/en/DeviceDoc/60001185F.pdf
Analog pin Section 12.2.5 http://ww1.microchip.com/downloads/en/DeviceDoc/60001120F.pdf

Answer 2

Hi everyone and thanks for your replies !
Thanks to your help, i found out that issue. Pin configuration was necesary. Below the code i added for pin configuration.
// Mapping SPI1 & SPI2
SDI1Rbits.SDI1R = 0xa; // SDI1 to C4
RPD0Rbits.RPD0R = 0x8; // SDO1 to D0
RPB2Rbits.RPB2R = 0x7; // SS1 to B2
SDI2Rbits.SDI2R = 0x1; // SDI2 to G7
RPG8Rbits.RPG8R = 0x6; // SDO2 to G8
RPG9Rbits.RPG9R = 0x6; // SS2 to G9