commit ade55edd61344aa760e0c303cfa6fe507fc9edfe
Author: James Devine <devine.jd@gmail.com>
Date:   Mon Jul 30 21:32:56 2018 +0200

diff --git a/DUESPITestMasterandSlave.ino b/DUESPITestMasterandSlave.ino
new file mode 100644
index 0000000..aa6ea07
--- /dev/null
+++ b/DUESPITestMasterandSlave.ino
@@ -0,0 +1,221 @@
+#include <SPI.h>
+
+/* Cosmic Pi SPI test routines - Master version, slave is commented out below. Runs on an Arduino DUE,
+ *  Pinouts:
+ *  MOSI - MOSI
+ *  MISO - MISO
+ *  SCK - SCK
+ *  Pin 10 - Pin 10 (SS)
+ *  GND - GND
+ *  5V - 5V
+ *  
+ *  The slave echoes the master byte in the next (16 bit) transmission. 
+
+
+
+
+SPI COMMUNICATION TRANSACTION LIST OF COMMANDS
+
+WRITE OPERATIONS (FOR EACH WRITE, SLAVE MUST SEND BACK THE VALUE IT RECEIVES)
+
+01  WRITE MSB(16 high bits) HV1_DUTY_CYCLE
+02  WRITE LSB(16 low bits) HV1_DUTY_CYCLE
+03  WRITE MSB(16 high bits) HV2_DUTY_CYCLE
+04  WRITE LSB(16 low bits) HV2_DUTY_CYCLE
+05  WRITE 16 bits LED_DUTY_CYCLE
+
+READ OPERATIONS (FOR EACH READ, SLAVE MUST SEND BACK THE VALUE OF THE RELATED REGISTER)
+
+06  READ MSB(16 high bits) HV1_DUTY_CYCLE
+07  READ LSB(16 low bits) HV1_DUTY_CYCLE
+08  READ MSB(16 high bits) HV2_DUTY_CYCLE
+09  READ LSB(16 low bits) HV2_DUTY_CYCLE
+10  READ 16 bits LED_DUTY_CYCLE
+
+11  WRITE STATUS
+11  READ STATUS
+
+
+*/
+
+byte CMD=1;
+
+unsigned int duty_cycle_LED = 81;
+unsigned int duty_cycle_channel_A = 100000;
+unsigned int duty_cycle_channel_B = 200000;
+unsigned int MSB;
+unsigned int LSB;
+
+//unsigned int response = 0;
+unsigned int answer = 0;
+byte PSU_parametrized = 0;
+
+void setup() {
+
+pinMode(SS, OUTPUT);
+
+  SPI.begin();
+  SPI.setBitOrder(MSBFIRST);
+  //SPI.setClockDivider(SPI_CLOCK_DIV128 );
+  Serial.begin(9600);
+  
+  //delay(500);
+
+}
+
+
+void loop() {
+
+
+
+
+      // WRITE OPERATIONS
+      Serial.println("*******************  WRTTE  OPERATIONS  *************************");
+
+      /********************* HV1 DUTY CYCLE *********************************/
+
+ 
+      delay(20);
+
+      //MSB
+      MSB = duty_cycle_channel_A >> 16;
+      spi_exchange(1);
+      spi_exchange(MSB);
+
+      //LSB
+      LSB = duty_cycle_channel_A & 0x0000FFFF;
+      spi_exchange(1);
+      spi_exchange(LSB);
+
+      /********************* HV2 DUTY CYCLE *********************************/
+      //MSB
+      MSB = duty_cycle_channel_B >> 16;
+      spi_exchange(3);
+      spi_exchange(MSB);
+
+      //LSB
+      LSB = duty_cycle_channel_B & 0x0000FFFF;
+      spi_exchange(4);
+      spi_exchange(LSB);
+
+
+      /********************* LED DUTY CYCLE *********************************/
+      spi_exchange(5);
+      spi_exchange(duty_cycle_LED);
+
+      // READ OPERATIONS
+      Serial.println("*******************  READ  OPERATIONS  *************************");
+      
+      /********************* HV1 DUTY CYCLE *********************************/
+      //MSB
+      spi_exchange(6);
+      spi_exchange(255);
+
+      //LSB
+      CMD=7;
+      spi_exchange(CMD);
+      spi_exchange(255);
+
+
+      /********************* HV2 DUTY CYCLE *********************************/
+      //MSB
+      CMD=8;
+      spi_exchange(CMD);
+      spi_exchange(255);
+
+      //LSB
+      CMD=9;
+      spi_exchange(CMD);
+      spi_exchange(255);
+
+      /********************* LED DUTY CYCLE *********************************/
+      CMD=10;
+      spi_exchange(CMD);
+      spi_exchange(255);
+
+      /********* STATUS *******/
+      // WRITE
+      CMD=11;
+      spi_exchange(CMD);
+      spi_exchange(11);
+
+      // READ
+      CMD=12;
+      spi_exchange(CMD);
+      spi_exchange(255);
+
+  
+      delay(4000);
+
+
+}
+
+int spi_exchange(int data){
+      digitalWrite(SS, LOW);
+      int response = SPI.transfer16(data);
+      Serial.println("Master send command:" + String(data) + " Slave reply:" + String(response));
+      digitalWrite(SS, HIGH);
+      delay(20);
+      return response;
+}
+
+/*Arduino SPI slave test code that I found on https://github.com/manitou48/DUEZoo/blob/master/spislave.ino
+ * Nice one Manitou, it worked first time
+
+#include <SPI.h>
+
+// assumes MSB
+static BitOrder bitOrder = MSBFIRST;
+
+void slaveBegin(uint8_t _pin) {
+  SPI.begin(_pin);
+  REG_SPI0_CR = SPI_CR_SWRST;     // reset SPI
+  REG_SPI0_CR = SPI_CR_SPIEN;     // enable SPI
+  REG_SPI0_MR = SPI_MR_MODFDIS;     // slave and no modefault
+  REG_SPI0_CSR = SPI_MODE0;    // DLYBCT=0, DLYBS=0, SCBR=0, 8 bit transfer
+}
+
+
+byte transfer(uint8_t _pin, uint8_t _data) {
+    // Reverse bit order
+    if (bitOrder == LSBFIRST)
+        _data = __REV(__RBIT(_data));
+    uint32_t d = _data;
+
+    while ((REG_SPI0_SR & SPI_SR_TDRE) == 0) ;
+    REG_SPI0_TDR = d;
+
+    while ((REG_SPI0_SR & SPI_SR_RDRF) == 0) ;
+    d = REG_SPI0_RDR;
+    // Reverse bit order
+    if (bitOrder == LSBFIRST)
+        d = __REV(__RBIT(d));
+    return d & 0xFF;
+}
+
+#define PRREG(x) Serial.print(#x" 0x"); Serial.println(x,HEX)
+
+void prregs() {
+  Serial.begin(9600);
+  while(!Serial);
+  PRREG(REG_SPI0_MR);
+  PRREG(REG_SPI0_CSR);
+  PRREG(REG_SPI0_SR);
+}
+
+
+#define SS 10
+void setup() {
+  slaveBegin(SS);
+  prregs();  // debug
+}
+
+void loop() {
+  byte in;
+  static byte out=0x83;
+
+  in = transfer(SS, out);
+  out = in;
+}
+
+*/
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