spi module update

modules/spi/nrfer_spi_alive/nrfer_spi_alive.ino

-#include <AccelStepper.h>
-#include "pins.h"
-
-AccelStepper stepper(AccelStepper::DRIVER, STEP_PIN, DIR_PIN);
-
-void setup() {
-  pinMode(LED_PIN_1, OUTPUT);
-  pinMode(LED_PIN_2, OUTPUT);
-  pinMode(LED_PIN_3, OUTPUT);
-  outclr(LED_PIN_1);
-  outclr(LED_PIN_2);
-  outclr(LED_PIN_3);
-
-  stepper.setEnablePin(ENABLE_PIN);
-  stepper.setPinsInverted(false, false, true);
-  stepper.setMaxSpeed(10000.0);
-  stepper.setAcceleration(1000.0);
-  stepper.enableOutputs();
-  stepper.moveTo(5000);
-
-  SPI_Setup();
-
-  Serial.begin(115200);
-}
-
-uint32_t ticker = 0;
-bool cntr = true;
-
-void loop() {
-  ticker ++;
-
-  if (stepper.distanceToGo() == 0 ) {
-    stepper.moveTo(-stepper.currentPosition());
-  }
-
-  //stepper.run();
-
-  if (!(ticker % 25000)) {
-    SPI_Test();
-    if (cntr) {
-      cntr = false;
-      outclr(LED_PIN_2);
-    } else {
-      cntr = true;
-      outset(LED_PIN_2);
-    }
-  }
-}
-
-#define NRF_SPI_BUFFER_SIZE 4 // 5 8-bit words, making up:
-#define NRF_SPI_NUM_BUFFER 1 // one buffer, one 40-bit word
-
-typedef struct SPIArrayList {
-  uint8_t buffer[NRF_SPI_BUFFER_SIZE];
-} SPIArrayList_type;
-
-SPIArrayList_type RX_Buffer[NRF_SPI_NUM_BUFFER]; // 3 words
-SPIArrayList_type TX_Buffer[NRF_SPI_NUM_BUFFER];
-
-void SPI_Setup() {
-  /*
-     NRF52 Datasheet pg 283: must cfg pins for GPIO 1st
-     CS: Output, value 0
-     SCK: Output, value 'same as CONFIG.CPOL' (so dep. on SPI mode)
-     MOSI: Output, value 0
-     MISO: Input
-  */
-  NRF_GPIO->DIRSET = (1 << CS_PIN);
-  NRF_GPIO->DIRSET = (1 << SCK_PIN);
-  NRF_GPIO->DIRSET = (1 << MOSI_PIN);
-  NRF_GPIO->DIRSET = (0 << MISO_PIN);
-  /*
-     Enabling SPI, setting pins
-     CS Pin is not associated with this module, u do u
-  */
-  NRF_SPIM0->ENABLE = SPIM_ENABLE_ENABLE_Enabled;
-  NRF_SPIM0->PSEL.SCK = SCK_PIN;
-  NRF_SPIM0->PSEL.MOSI = MOSI_PIN;
-  NRF_SPIM0->PSEL.MISO = MISO_PIN;
-  /*
-     Frequency
-  */
-  NRF_SPIM0->FREQUENCY = SPI_FREQUENCY_FREQUENCY_K250;
-  /*
-     Config
-  */
-  NRF_SPIM0->CONFIG = (SPIM_CONFIG_CPOL_Msk << SPIM_CONFIG_CPOL_ActiveHigh) |
-                      (SPIM_CONFIG_CPHA_Msk << SPIM_CONFIG_CPHA_Leading) |
-                      (SPIM_CONFIG_ORDER_Msk << SPIM_CONFIG_ORDER_MsbFirst);
-  /*
-     DMA to Send Buffers
-  */
-  NRF_SPIM0->TXD.MAXCNT = NRF_SPI_BUFFER_SIZE * NRF_SPI_NUM_BUFFER;
-  NRF_SPIM0->TXD.PTR = (uint32_t)&TX_Buffer;
-  NRF_SPIM0->RXD.MAXCNT = NRF_SPI_BUFFER_SIZE * NRF_SPI_NUM_BUFFER;
-  NRF_SPIM0->RXD.PTR = (uint32_t)&RX_Buffer;
-
-  //outset(CS_PIN);
-}
-
-void SPI_Test() {
-  for (int i = 0; i < NRF_SPI_NUM_BUFFER; i++) {
-    TX_Buffer[i].buffer[0] = 0x6F; // addr. byte
-    TX_Buffer[i].buffer[1] = 0x00;
-    TX_Buffer[i].buffer[2] = 0x00;
-    TX_Buffer[i].buffer[3] = 0x00;
-  }
-
-  NRF_SPIM0->EVENTS_STARTED = 0;
-  NRF_SPIM0->EVENTS_END = 0;
-  outclr(CS_PIN); // go lo
-  NRF_SPIM0->TASKS_START = 1;
-
-  outset(LED_PIN_3);
-  while (NRF_SPIM0->EVENTS_STARTED == 0) {} // wait 4 start
-  outclr(LED_PIN_3);
-  outset(LED_PIN_1);
-  while (NRF_SPIM0->EVENTS_END == 0) {} // does the business
-  outclr(LED_PIN_1);
-  outset(CS_PIN);
-}
-
-void outclr(uint8_t pin) {
-  NRF_GPIO->OUTCLR = (1 << pin);
-}
-
-void outset(uint8_t pin) {
-  NRF_GPIO->OUTSET = (1 << pin);
-}

modules/spi/nrfer_spi_alive/pins.h

-#ifndef PINS_H
-#define PINS_H
-
-#define LED_PIN_1   20 // R 
-#define LED_PIN_2   11 // G
-#define LED_PIN_3   12 // B
-
-#define STEP_PIN    13
-#define DIR_PIN     18
-#define ENABLE_PIN  3
-
-#define DIAG0       7
-#define DIAG1       9
-
-#define MOSI_PIN    14
-#define MISO_PIN    10
-#define SCK_PIN     16
-#define CS_PIN      19
-
-#endif

modules/spi/spi.ino

+/*
+   Pins for SPI
+*/
+#define MOSI_PIN    14
+#define MISO_PIN    2
+#define SCK_PIN     16
+#define CS_PIN      19
+
+/*
+   buffers
+*/
+#define NUM_WORDS_BUFFER    1 // # of 'words' in the buffer
+#define NUM_BYTES_WORD   5 // # of bytes per 'word'
+
+typedef struct SPIArrayList {
+  uint8_t buf[NUM_BYTES_WORD];
+} SPIArrayList_type;
+
+SPIArrayList_type SPI_RX[NUM_WORDS_BUFFER];
+SPIArrayList_type SPI_TX[NUM_WORDS_BUFFER];
+
+void setup() {
+  /*
+     NRF52 Datasheet pg 283: must cfg pins for GPIO 1st
+     CS: Output, value 0
+     SCK: Output, value 'same as CONFIG.CPOL' (so dep. on SPI mode)
+     MOSI: Output, value 0
+     MISO: Input
+     FOR REGISTERS: look in (version #s may change) (from windows machine, probably different-but-similar on mac / ubuntu
+     /yourusername/AppData/Local/Arduino15/packages/adafruit/hardware/nrf52/0.7.5/cores/nRF5/SKD/components/device/nrf52_bitfields.h
+     and /nrf.h
+     and /nrf52.h
+     also available in SDK from Nordic
+  */
+  NRF_GPIO->DIRSET = (1 << CS_PIN);
+  NRF_GPIO->DIRSET = (1 << SCK_PIN);
+  NRF_GPIO->DIRSET = (1 << MOSI_PIN);
+  NRF_GPIO->DIRSET = (0 << MISO_PIN);
+  NRF_GPIO->PIN_CNF[MISO_PIN] = (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos) |
+                                (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos);
+  /*
+     Enabling SPI, setting pins
+     CS Pin is not associated with this module, u do u
+  */
+  NRF_SPIM0->ENABLE = (SPIM_ENABLE_ENABLE_Enabled << SPIM_ENABLE_ENABLE_Pos);
+  NRF_SPIM0->PSEL.SCK = SCK_PIN;
+  NRF_SPIM0->PSEL.MOSI = MOSI_PIN;
+  NRF_SPIM0->PSEL.MISO = MISO_PIN;
+  /*
+     Frequency - device & electronics quality dependent. I generally dial this up until it breaks, and then come down by 2/3
+  */
+  NRF_SPIM0->FREQUENCY = SPI_FREQUENCY_FREQUENCY_M1; // 1MBps
+  // SPI_FREQUENCY_FREQUENCY_K250 // 250kB/s
+  // SPI_FREQUENCY_FREQUENCY_K500 // 500kB/s
+  // SPI_FREQUENCY_FREQUENCY_M1 // 1MB/s
+  // SPI_FREQUENCY_FREQUENCY_M2 // 2MB/s
+  /*
+     Config - device dependent, best to read datasheet carefully
+  */
+  NRF_SPIM0->CONFIG = (SPIM_CONFIG_CPOL_Msk << SPIM_CONFIG_CPOL_ActiveHigh) | // or ActiveLow
+                      (SPIM_CONFIG_CPHA_Msk << SPIM_CONFIG_CPHA_Leading) |    // or CPHA_Trailing
+                      (SPIM_CONFIG_ORDER_Msk << SPIM_CONFIG_ORDER_LsbFirst);  // or MsbFirst
+  /*
+     DMA to Send Buffers
+     MAXCNT is the # of bytes the SPI module will send
+     PTR an address to those bytes. see globally defined buffers above
+  */
+  NRF_SPIM0->TXD.MAXCNT = NUM_BYTES_WORD * NUM_WORDS_BUFFER;
+  NRF_SPIM0->TXD.PTR = (uint32_t)&SPI_TX;
+  NRF_SPIM0->RXD.MAXCNT = NUM_BYTES_WORD * NUM_WORDS_BUFFER;
+  NRF_SPIM0->RXD.PTR = (uint32_t)&SPI_RX;
+
+  NRF_GPIO->OUTSET = (1 << CS_PIN); // set line inactive (high)
+
+  Serial.begin(115200); // for testing
+}
+
+uint32_t lastms = 0;
+uint32_t period = 1000;
+
+void loop() {
+  if((millis() - lastms) > period){
+    lastms - millis();
+    /*
+     * setup your buffer, do this however you'd like
+     */
+    SPI_TX[0].buf[0] = 0x00;
+    SPI_TX[0].buf[1] = 0x01;
+    SPI_TX[0].buf[2] = 0x02;
+    SPI_TX[0].buf[3] = 0x03;
+    SPI_TX[0].buf[4] = 0x04;
+    /*
+     * do the business
+     */
+    blockingSpiTransfer();
+    /*
+     * reply is now available in SPI_RX[0].buf[n] 
+     * -> this is set up as an MD array because most spi 'words' are longer than 1 byte,
+     * so it's useful to have a buffer[x].ofWords[n]
+     * in the event you are transferring lots of data and want to not-block, 
+     * you can keep filling the buffer[x] and set up events to fire when it's empty, full etc...
+     */
+     Serial.print(SPI_RX[0].buf[0], BIN); // will print 0s and 1s to the line, can also spec HEX (default is ASCII)
+     Serial.print(" | ");
+     Serial.print(SPI_RX[0].buf[1], BIN);
+     Serial.print(" | ");
+     Serial.print(SPI_RX[0].buf[2], BIN);
+     Serial.print(" | ");
+     Serial.print(SPI_RX[0].buf[3], BIN);
+     Serial.print(" | ");
+     Serial.print(SPI_RX[0].buf[4], BIN);
+     Serial.print(" | ");
+     /*
+      * also: when reading a register, you normally have to send the 'read from' command twice
+      * as the device has to have a chance to shift its reply bits into the buffer it uses to reply with.
+      */
+  }
+}
+
+
+void blockingSpiTransfer() {
+  NRF_GPIO->OUTCLR = (1 << CS_PIN); // tells device to start listening (active low)
+
+  NRF_SPIM0->EVENTS_STARTED = 0; // clear these events
+  NRF_SPIM0->EVENTS_END = 0;
+  NRF_SPIM0->TASKS_START = 1; // ready go 
+
+  // now SPI hardware is pulling from the TX and pushing into the RX buffers
+
+  while (NRF_SPIM0->EVENTS_STARTED == 0) {} // wait 4 start
+  while (NRF_SPIM0->EVENTS_END == 0) {} // wait 4 spi module to do the business (todo: non blocking event based C++!)
+
+  NRF_GPIO->OUTSET = (1 << CS_PIN); // goodbye
+}