From dbd69c72842b4fc213e707f11d7f37c18e0a9a75 Mon Sep 17 00:00:00 2001
From: Kai Lauterbach <klaute@gmx.de>
Date: Wed, 14 Feb 2024 16:42:47 +0100
Subject: [PATCH] Added genral support for DAC MCP4725

---
 firmware/command_ctrl.ino      | 22 +++++-----------------
 firmware/firmware.ino          | 30 ++++++++++++++++++++++++++++++
 firmware/globals.h             |  7 ++++++-
 firmware/waveformgenerator.ino |  7 ++++---
 4 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/firmware/command_ctrl.ino b/firmware/command_ctrl.ino
index bc73bbb..b52d164 100644
--- a/firmware/command_ctrl.ino
+++ b/firmware/command_ctrl.ino
@@ -241,14 +241,8 @@ void cc_startMeasurement()
     // TODO an diesem punkt muss unterschieden werden ob eine waveform ausgegeben werden soll oder eine frequenz, und welche Art von Kurve
     if (freq < WF_FREQ_MAX_HZ)
     {
-      if (freq > PWM_MAX_VALUE)
-      {
-        setWaveform(WAVEFORM_SINUS);
-        setWaveformFrequency(freq);
-      } else {
-        setWaveform(WAVEFORM_DUTYCYCLE);
-        setWaveformDC((uint8_t)(freq & 0xff));
-      }
+      setWaveformFrequency(freq);
+
       enableWaveformOutput();
       pollWaveformGenerator(); // manually poll the waveformgenerator
       si5351.output_enable(SI5351_CLK0, 0); // disable clock output 0
@@ -315,7 +309,7 @@ void cc_getConfig()
   send32BitValue(end_freq);
   send32BitValue(step_freq);
   send16BitValue(intervall);
-  Serial.write((uint8_t) drive_str);
+  Serial.write((uint8_t)drive_str);
   sendEOM();
 }
 
@@ -328,14 +322,8 @@ void cc_enableClk(void)
   {
     if (start_freq < WF_FREQ_MAX_HZ) // < 8kHz
     {
-      if (start_freq > PWM_MAX_VALUE) // > 8 bit pwm value
-      {
-        setWaveform(WAVEFORM_SINUS);
-        setWaveformFrequency(start_freq);
-      } else {
-        setWaveform(WAVEFORM_DUTYCYCLE);
-        setWaveformDC((uint8_t)(start_freq & 0xff));
-      }
+      setWaveformFrequency(start_freq);
+
       enableWaveformOutput();
       si5351.output_enable(SI5351_CLK0, 0);
     } else {
diff --git a/firmware/firmware.ino b/firmware/firmware.ino
index a3555f7..af8db88 100644
--- a/firmware/firmware.ino
+++ b/firmware/firmware.ino
@@ -6,7 +6,9 @@
 
 /*****************************************************************************/
 
+#include <Adafruit_MCP4725.h>
 #include <si5351.h>
+
 #include "Wire.h"
 
 #include <EEPROM.h>
@@ -19,11 +21,13 @@ extern "C" {
 /*****************************************************************************/
 
 Si5351 si5351;
+Adafruit_MCP4725 dac;
 
 uint32_t start_freq = 10000;
 uint32_t   end_freq = 50000000;
 uint32_t  step_freq = 1000000; // 1 MHz default step size
 uint16_t  intervall = 1000; // intervall to change the frequency as milli seconds
+
 enum si5351_drive drive_str = SI5351_DRIVE_2MA;
 
 /*****************************************************************************/
@@ -49,6 +53,17 @@ void setup()
   // initialize the command control module
   cc_init();
 
+  if (dac.begin(0x62))
+  {
+    bool tmp = dac.setVoltage(500, false, 100000);
+    if (!tmp)
+    {
+      blinkCode(150);
+    }
+  } else {
+    blinkCode(500);
+  }
+
   // init the Si5351
   si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0);
 
@@ -192,3 +207,18 @@ uint32_t keepFreqRange(uint32_t freq)
 }
 
 /*****************************************************************************/
+
+void blinkCode(uint16_t d)
+{
+  pinMode(13, OUTPUT);
+  while (true)
+  {
+    digitalWrite(13, HIGH);
+    delay(d);
+    digitalWrite(13, LOW);
+    delay(d);
+    Serial.write(MSG_TYPE_ANSWER_NOK);
+  }
+}
+
+/*****************************************************************************/
diff --git a/firmware/globals.h b/firmware/globals.h
index 72f8e43..7c6502c 100644
--- a/firmware/globals.h
+++ b/firmware/globals.h
@@ -5,8 +5,13 @@
 
 /*****************************************************************************/
 
-#define PWM_BIT_WIDTH 8
+#define DAC_I2C_ADDRESS 0x62
+#define DAC_MAX_VOLTAGE 0xfff
+
+/*****************************************************************************/
+
 #define PWM_PIN       5 // PWM-Pin für DAC0 auf dem Arduino Nano 328
+#define PWM_BIT_WIDTH 12
 #define PWM_MAX_VALUE ((1 << PWM_BIT_WIDTH)-1)
 
 /*****************************************************************************/
diff --git a/firmware/waveformgenerator.ino b/firmware/waveformgenerator.ino
index ac84ac6..be0a0b8 100644
--- a/firmware/waveformgenerator.ino
+++ b/firmware/waveformgenerator.ino
@@ -82,10 +82,10 @@ void pollWaveformGenerator()
       {
           wf_prevMicros = currentMicros;
 
-          uint16_t sample = map(waveformsTable[wf_wave0][wf_pos], 0, 0xfff, 0, PWM_MAX_VALUE);
-          sample = constrain(sample, 0, PWM_MAX_VALUE);
+          uint16_t sample = map(waveformsTable[wf_wave0][wf_pos], 0, 0xfff, 0, DAC_MAX_VOLTAGE);
+          sample = constrain(sample, 0, DAC_MAX_VOLTAGE);
           // TODO write the selected waveform on DAC0
-          analogWrite(PWM_PIN, sample);
+          dac.setVoltage(sample, false, 100000); // do not write to EEPROM, 400000Hz DAC frequency
 
           wf_pos++;
           if (wf_pos == WAVEFORM_MAX_SAMPLES_NUM)  // Reset the counter to repeat the wave
@@ -104,6 +104,7 @@ void pollWaveformGenerator()
   } else {
     if (wf_pwm_needs_disabling)
     {
+      dac.setVoltage(0, false, 400000);
       analogWrite(PWM_PIN, 0);
       wf_pwm_needs_disabling = false;
     }