sketch: GoSpectro spectrometer

/*
 * Initial test program for
 * Adafruit Feather nRF52832 with XSPECLUM01 board.
 *
 * Core:
 * Initiate the ports and read the internal
 * sensor for Temperature and Relative Humidity
 *
 * Note: the feather needs to be removed from the board when updated,
 * since the bootloader does not set nKILL high (which will turn off the device after a few hundreds of ms).
 *
 */

#define DAC6571_ADDR 0x4C

#define BNC               A0
#define SPECTRO_AN        A1 // The analog video signal for the spectrometer
#define GX16_AN           A2 // The GX16 analog sensor signal
#define nKILL             17
#define nPBINT            18
#define ONEWIRE           19

#define GPIOSCK           26  // NC
#define nRE               25
#define GPIOMISO          24
#define GPIORX            1
#define GPIOTX            0
#define GPIOD2            2

#define SPECTRO_CLK       13
#define SPECTRO_ST        12
#define SPECTRO_TRG       11
#define SPECTRO_EOS       10
#define SPECTRO_BOOST_EN  9

#define LED_BUCK_EN       6
#define LED_PULSE         5

#define GPIOSCL           23
#define GPIOSDA           22

#define USERSWITCH        7
#define BATTERYV2         A6
#define NEOPIXEL          8

/* Define the channels of the spectrometer
  The definition below, 256 channels starting at channel 64 is for HAMAMATSU SMD
*/

#define SPECTRO_CHANNELS          256 // Nr of spectral channels in sensor
#define SPECTRO_START_CHANNEL     64 // First channel with valid data
#define SPECTRO_END_CHANNEL       256 // Last channel with valid data
#define SPECTRO_integration_time  300 // Integration time for spectral sensor sampling ("expsoture rime")

uint16_t data[SPECTRO_CHANNELS];

#include <Adafruit_NeoPixel.h>    //  Library that provides NeoPixel functions

// -- Create a NeoPixel object called onePixel that addresses 1 pixel in pin 8
Adafruit_NeoPixel rgbPixel = Adafruit_NeoPixel(1, 8, NEO_GRB + NEO_KHZ800);

#include <Wire.h>                 // Library
#include "SHT2x.h"                // Library for in-box temperature and relaive humidity

// -- Create a SHT2x object called sht for accessing the in-box Temperature and Relative Humidity
SHT2x sht;



/* tinyusb is for the serical connection with Adafruit nRF52 boards */
#if defined(USE_TINYUSB)
#include <Adafruit_TinyUSB.h> // for Serial
#endif

void setup() {

  pinMode(BNC,      INPUT);  // BNc connection - usually an Ion Selecteve Electrode (ISE)
  pinMode(SPECTRO_AN,   INPUT);  // Spectro video analog signal
  pinMode(GX16_AN,      INPUT);  // Aalog signal from GX16 expansion socket)
  pinMode(nKILL,    OUTPUT); // #KILL
  pinMode(nPBINT,   INPUT);  // #PBINT (pushbutton)
  pinMode(ONEWIRE,   INPUT);  // 1W interface (pulled up to 3v3 by 2k2)
  pinMode(SCK,      OUTPUT); // - (not connected)
  pinMode(nRE,      OUTPUT); // #RE (Receive enabled, RS485)
  pinMode(GPIOMISO, OUTPUT); // - (not connected)
  pinMode(GPIORX,   INPUT);  // Rx (Uart)
  pinMode(GPIOTX,   OUTPUT); // Tx (Uart)
  pinMode(GPIOD2,   OUTPUT); // - (not connected)

  pinMode(SPECTRO_CLK,   OUTPUT); // Spectrometer clock pulse
  pinMode(SPECTRO_ST,    OUTPUT); // Spectrometer start pulse
  pinMode(SPECTRO_TRG,   INPUT);  // Spectrometer trigger pulse
  pinMode(SPECTRO_EOS,   INPUT);  // SPECTRO_EOS
  pinMode(SPECTRO_BOOST_EN, OUTPUT); // Spectrometer end of scan

  pinMode(LED_BUCK_EN,  OUTPUT); // LED_BUCK_EN
  pinMode(LED_PULSE,    OUTPUT); // LED_PULSE

  pinMode(GPIOSCL,  INPUT);  // SCL
  pinMode(GPIOSDA,  INPUT);  // SDA

  pinMode(USERSWITCH,   INPUT);  // User switch

  pinMode(A6,           INPUT);  // Battery voltage/2
  pinMode(LED_BUILTIN,  OUTPUT); // Red LED

  pinMode(NEOPIXEL,     OUTPUT); // RGB LED

  digitalWrite(nKILL, HIGH);     // Keep the unit on. 3v3 feeds Rh/T sensor, Ph sensor and LED driver DAC
  digitalWrite(nRE, HIGH);       // Set transmit mode
  digitalWrite(SPECTRO_CLK, LOW);
  digitalWrite(SPECTRO_ST, LOW);
  digitalWrite(SPECTRO_BOOST_EN, LOW);

  digitalWrite(LED_BUCK_EN, LOW);

  Serial.begin(115200);

  // Light source
  // Turn off LED_PULSE before starting
  //  digitalWrite(LED_PULSE, LOW);
  digitalWrite(LED_PULSE, LOW);

  // Start LED driver
  digitalWrite(LED_BUCK_EN, HIGH);
  //  Turn on LED_PULSE;
  digitalWrite(LED_PULSE, HIGH);

  // Prepare the builtin neopixel - will loop the rainbow to indicate that spetrometer is scanning
  rgbPixel.begin();             // Start the NeoPixel object
  rgbPixel.clear();             // Set NeoPixel color to black (0,0,0)
  rgbPixel.setBrightness(20);   // Affects all subsequent settings
  rgbPixel.show();              // Update the pixel state

  // Blink the built-in REd and BLUE lights
  digitalWrite(LED_RED, HIGH);
  digitalWrite(LED_BLUE, HIGH);
  delay(100);   
  digitalWrite(LED_RED, LOW);
  digitalWrite(LED_BLUE, LOW);

  // Initate the in-box temperature + Reative Humidity driver
  sht.begin();
}

/* Set the DAC voltage*/

// Set DAC voltage (raw DAC value)
// 12 bit, 0-4095 <=> 0-3.3V
void DAC6571_setVoltage(uint16_t v)
{
  uint16_t vh,vl;

  vh=(v>>8) & 0xff;
  vl=v & 0xff;

  Wire.beginTransmission(DAC6571_ADDR);
  Wire.write(vh); // PD bits =0 (bit 4-5) = Normal operation
  Wire.write(vl);
  Wire.endTransmission();
}

#define RA 68.0
#define RB 16.9
#define RD 75.0
#define DAC_VREF_mV 3300.0
#define DAC_MAX 4095.0

void LED_setVoltage_mV(float vset_mV)
{
  float vdac_mV=600*(RD/RB+1)+(600-vset_mV)*RD/RA;
  //  (600.0*(1+RA/RB)-vset_mV)*RD/RA+600.0;
  float r=vdac_mV/DAC_VREF_mV*DAC_MAX;

  DAC6571_setVoltage((uint16_t)r);
}

/* Separate functions for all the sensors */

/* In-box temperature and Relative Humidity sensor*/

void InBoxShtTempRh(bool fullprint=0, bool valueprint=1) {
  float temp;
  float humidity;

  sht.read();  // Read Rh/T sensor

  temp = sht.getTemperature();

  humidity = sht.getHumidity();

  if (fullprint){
    Serial.print("Box temperature= ");
    Serial.print(temp, 1);
    Serial.print("'C\t Box relative Humidity= ");
    Serial.print(humidity, 1);
    Serial.print("'%\n");
  }
  else if (valueprint) {
    Serial.print("T/Rh: ");
    Serial.print(temp, 1);
    Serial.print(",");
    Serial.print(humidity, 1);
    Serial.print("\n");
  }

}

/* END - Separate functions for all the sensors */

#define VSET_mV 3000

float LED_vset_mV = VSET_mV;

int red = 0; int green = 0; int blue = 0;

int loopnr = 0;

void loop()
{

  loopnr+=1;

  // Step rgbpixel values blue - gree - yellow - red - purple -blue
  if (loopnr == 1) { red=0; green=0; blue=100; }
  else if (loopnr == 2) { red=0; green=100; blue=0; }
  else if (loopnr == 3) { red=80; green=80; blue=0; }
  else if (loopnr == 4) { red=100; green=0; blue=0; }
  else  { red=80; green=0; blue=80; }

  rgbPixel.setPixelColor(0, red, green, blue); //  Set pixel 0 to (r,g,b) color value

  rgbPixel.show(); //  Update pixel state

  digitalWrite(LED_RED, HIGH);

  if (loopnr == 5) {
    loopnr = 0;
  }

  bool fullprint = 0;
  bool valueprint = 1;
  InBoxShtTempRh(fullprint, valueprint);


  delay (200);

  digitalWrite(LED_RED, LOW);

  delay (200);

}