new ADC: NAU7802, new library versions

README.md

@@ -3,3 +3,33 @@
 Code fuer den LoraWAN Node
 
 Autor: Joerg Lehmann, nbit Informatik GmbH
+
+| Parameter         | Value                       |
+| ----------------- | --------------------------- |
+| Board             | MCCI Catena 4610            |
+| LoraWAN Subband   | "Default, works everywhere" |
+| Serial interface  | Generic Serial              | 
+| LoraWAN Network   | Swisscom                    |
+| System Clock      | 24 MHz                      |
+| LoraWAN Region    | Europe 868 MHz              |
+| Optimize          | Smallest (-Os default)      |
+
+Das sind die verwendeten Libraries [1]:
+
+| URL | Commit | Commit Date |
+| --- | -----  | ----------- |
+| https://github.com/mcci-catena/Adafruit_BME280_Library.git  | 3dafbe1 | Wed, 13 Dec 2017 13:56:30 -0500  |
+| https://github.com/mcci-catena/Adafruit_Sensor.git  | f2af6f4 | Tue, 1 Sep 2015 15:57:59 +0200  |
+| https://github.com/mcci-catena/arduino-lmic.git  | 6fe04ec | Tue, 12 May 2020 09:16:47 -0400  |
+| https://github.com/mcci-catena/arduino-lorawan.git  | 4bc0d48 | Sat, 9 May 2020 12:38:28 -0400  |
+| https://github.com/mcci-catena/Catena-Arduino-Platform.git  | 92019ca | Tue, 12 May 2020 01:34:08 -0400  |
+| https://github.com/mcci-catena/Catena-mcciadk.git  | a428006 | Sat, 21 Dec 2019 20:45:26 -0500  |
+| https://github.com/mcci-catena/MCCI_FRAM_I2C.git  | f0a5ea5 | Sat, 21 Dec 2019 16:17:01 -0500  |
+| https://github.com/tatobari/Q2-HX711-Arduino-Library.git  | ccda8d8 | Wed, 13 Mar 2019 12:41:44 -0300  |
+| https://github.com/sparkfun/SparkFun_Qwiic_Scale_NAU7802_Arduino_Library.git  | 688f255 | Fri, 3 Jan 2020 12:35:22 -0700  |
+| https://github.com/mcci-catena/OneWire.git  | d814a7b | Thu, 26 Apr 2018 03:45:27 +0800  |
+| https://github.com/mcci-catena/SHT1x.git  | be7042c | Tue, 20 Sep 2011 13:56:23 +1000  |
+
+
+`[1]:
+[joerg@cinnamon libraries]$ for i in Adafruit_BME280_Library Adafruit_Sensor arduino-lmic arduino-lorawan Catena-Arduino-Platform Catena-mcciadk MCCI_FRAM_I2C Q2-HX711-Arduino-Library SparkFun_Qwiic_Scale_NAU7802_Arduino_Library OneWire SHT1x ; do cd $i; echo "| $(git remote -v |grep fetch |awk '{print $2}' |tr '\n' ' ') | $(git log --pretty=format:'%h | %cD ' -n 1) |" ; cd ..; done`

helper.h

@@ -0,0 +1,78 @@
+#ifndef _HELPER_H_
+#define _HELPER_H
+
+#pragma once
+
+#ifndef _CATENA_H_
+#include <Catena.h>
+#endif
+
+using namespace McciCatena;
+
+// the primary object
+Catena gCatena;
+
+
+//Following functions are based on "https://github.com/dndubins/QuickStats", by David Dubins
+
+void bubbleSort(long A[], int len) {
+  unsigned long newn;
+  unsigned long n = len;
+  long temp = 0;
+  do {
+    newn = 1;
+    for (int p = 1; p < len; p++) {
+      if (A[p - 1] > A[p]) {
+        temp = A[p];         //swap places in array
+        A[p] = A[p - 1];
+        A[p - 1] = temp;
+        newn = p;
+      } //end if
+    } //end for
+    n = newn;
+  } while (n > 1);
+}
+
+long median(long samples[], int m) //calculate the median
+{
+  //First bubble sort the values: https://en.wikipedia.org/wiki/Bubble_sort
+  long sorted[m];   // Define and initialize sorted array.
+  long temp = 0;    // Temporary float for swapping elements
+
+  for (int i = 0; i < m; i++) {
+    sorted[i] = samples[i];
+  }
+  bubbleSort(sorted, m); // Sort the values
+
+  if (bitRead(m, 0) == 1) { //If the last bit of a number is 1, it's odd. This is equivalent to "TRUE". Also use if m%2!=0.
+    return sorted[m / 2]; //If the number of data points is odd, return middle number.
+  } else {
+    return (sorted[(m / 2) - 1] + sorted[m / 2]) / 2; //If the number of data points is even, return avg of the middle two numbers.
+  }
+}
+
+// Joergs STDDEV
+float stddev(long samples[], int m) //calculate the stdandard deviation
+{
+  float sum_x;
+  float sum_x2;
+  float mean;
+
+  float stdev;
+  sum_x = 0;
+  sum_x2 = 0;
+
+  for (int i = 0; i < m; i++) {
+    sum_x = sum_x + samples[i];
+  }
+  mean = sum_x / m;
+
+  for (int i = 0; i < m; i++) {
+    sum_x2 = sum_x2 + ((samples[i] - mean) * (samples[i] - mean));
+  }
+
+  stdev = sqrt(sum_x2 / m);
+
+  return stdev;
+}
+#endif

mini-beieli-node.ino

@@ -8,6 +8,9 @@
 
 */
 
+// HX711: 0 => compile for hx711, 1 => compile for NAU7802
+#define HX711 1
+
 #include <Catena.h>
 
 #include <Catena_Led.h>
@@ -25,9 +28,18 @@
 #include <cmath>
 #include <type_traits>
 
-#include <Q2HX711.h>
 #include "mini_beieli_node.h"
 
+#if (HX711)
+#include "mini_beieli_node_hx711.h"
+#else
+#include "mini_beieli_node_nau7802.h"
+#endif
+
+#ifndef _HELPER_H_
+#include "helper.h"
+#endif
+
 using namespace McciCatena;
 
 // forwards
@@ -104,10 +116,6 @@ uint32_t gRebootMs;
 // generic timer
 long t_cur;
 
-// the primary object
-Catena gCatena;
-
-//
 // the LoRaWAN backhaul.  Note that we use the
 // Catena version so it can provide hardware-specific
 // information to the base class.
@@ -131,9 +139,6 @@ SPIClass gSPI2(
 Catena_Mx25v8035f gFlash;
 bool fFlash;
 
-// Scales
-Q2HX711 hx711(A1, A0);
-
 //  USB power
 bool fUsbPower;
 
@@ -153,13 +158,10 @@ void setup(void)
 {
   gCatena.begin();
 
-  // Use D10 to regulate power
-  pinMode(D10, OUTPUT);
-
   setup_platform();
+  SetupScales(config_data.debug_level);
   ClearLoraData();
   setup_bme280();
-  //setup_scales();
 
   setup_flash();
   setup_uplink();
@@ -181,7 +183,7 @@ void setup_platform(void)
   if (config_data.debug_level > 0) {
     gCatena.SafePrintf("%010d - Reading Calibration Config from FRAM...\n", millis());
   }
-  gCatena.getFram()->getField(cFramStorage::kBme680Cal, (uint8_t *)&config_data, sizeof(config_data));
+  gCatena.getFram()->getField(cFramStorage::kAppConf, (uint8_t *)&config_data, sizeof(config_data));
 
   if (config_data.debug_level > 0) {
     gCatena.SafePrintf("%010d - setup_platform, this is the configuration\n", millis());
@@ -305,10 +307,7 @@ bool setup_scales(void)
   res = true;
 
   // Enable Power
-  digitalWrite(D10, HIGH);
+  PowerupScale();
-
-  // we wait 400ms (settling time according HX711 datasheet @ 10 SPS
-  delay(400);
 
   if (config_data.debug_level > 0) {
     gCatena.SafePrintf("%010d - setup_scale done\n", millis());
@@ -531,73 +530,11 @@ void DoDeepSleep(uint32_t sleep_time)
   }
 }
 
-//Following functions are based on "https://github.com/dndubins/QuickStats", by David Dubins
-
-long median(long samples[], int m) //calculate the median
-{
-  //First bubble sort the values: https://en.wikipedia.org/wiki/Bubble_sort
-  long sorted[m];   // Define and initialize sorted array.
-  long temp = 0;    // Temporary float for swapping elements
-
-  for (int i = 0; i < m; i++) {
-    sorted[i] = samples[i];
-  }
-  bubbleSort(sorted, m); // Sort the values
-
-  if (bitRead(m, 0) == 1) { //If the last bit of a number is 1, it's odd. This is equivalent to "TRUE". Also use if m%2!=0.
-    return sorted[m / 2]; //If the number of data points is odd, return middle number.
-  } else {
-    return (sorted[(m / 2) - 1] + sorted[m / 2]) / 2; //If the number of data points is even, return avg of the middle two numbers.
-  }
-}
-
-void bubbleSort(long A[], int len) {
-  unsigned long newn;
-  unsigned long n = len;
-  long temp = 0;
-  do {
-    newn = 1;
-    for (int p = 1; p < len; p++) {
-      if (A[p - 1] > A[p]) {
-        temp = A[p];         //swap places in array
-        A[p] = A[p - 1];
-        A[p - 1] = temp;
-        newn = p;
-      } //end if
-    } //end for
-    n = newn;
-  } while (n > 1);
-}
-
-long my_read_average(byte gain, byte times) {
-  long res;
-  int const num_scale_readings = 50; // number of instantaneous scale readings to calculate the median
-
-  // we use the median, not the average, see https://community.particle.io/t/boron-gpio-provides-less-current-than-electrons-gpio/46647/13
-  long readings[num_scale_readings];  // create arry to hold readings
-
-  if (config_data.debug_level > 0) {
-    gCatena.SafePrintf("%010d - my_read_average, measurements: ", millis());
-  }
-
-  hx711.setGain(gain);
-
-  for (int i = 0; i < num_scale_readings; i++) {
-    readings[i] = hx711.read();  // fill the array with instantaneous readings from the scale
-  }
-
-  res = median(readings, num_scale_readings); // calculate median
-
-  if (config_data.debug_level > 0) {
-    gCatena.SafePrintf("; median of %d samples: %d\n", num_scale_readings, res);
-  }
-
-  return res;
-}
-
 void ReadSensors(SENSOR_data &sensor_data) {
   SENSOR_data res;
   int32_t weight_current32;
+  long w1_0_real;
+  long w2_0_real;
 
   // vBat
   gCatena.poll();
@@ -608,33 +545,52 @@ void ReadSensors(SENSOR_data &sensor_data) {
   }
 
   // Read Scales
+  w1_0_real = config_data.cal_w1_0;
+  w2_0_real = config_data.cal_w2_0;
   if (setup_scales()) {
     if (config_data.debug_level > 0) {
-      gCatena.SafePrintf("%010d - HX711 LoadCell is ready.\n", millis());
+      gCatena.SafePrintf("%010d - LoadCell is ready.\n", millis());
     }
     gCatena.poll();
-    res.weight1 = (int32_t)my_read_average(32, 7);
+    if (config_data.cal_w1_0 != NOT_ATTACHED) {
-    if (config_data.debug_level > 0) {
+      res.weight1 = (int32_t)ReadScale('A');
-      gCatena.SafePrintf("%010d - Load_cell 1 weight1_current: %ld\n", millis(), res.weight1);
+      if (config_data.debug_level > 0) {
+        gCatena.SafePrintf("%010d - Load_cell 1 weight1_current: %ld\n", millis(), res.weight1);
+      }
+    } else {
+      res.weight1 = 0;
+      w1_0_real = 0;
+      if (config_data.debug_level > 0) {
+        gCatena.SafePrintf("%010d - Load_cell 1 is disabled\n", millis());
+      }
     }
     gCatena.poll();
-    res.weight2 = (int32_t)my_read_average(128, 7);
+    if (config_data.cal_w2_0 != NOT_ATTACHED) {
-    if (config_data.debug_level > 0) {
+      res.weight2 = (int32_t)ReadScale('B');
-      gCatena.SafePrintf("%010d - Load_cell 2 weight2_current: %ld\n", millis(), res.weight2);
+      if (config_data.debug_level > 0) {
+        gCatena.SafePrintf("%010d - Load_cell 2 weight2_current: %ld\n", millis(), res.weight2);
+      }
+    } else {
+      res.weight2 = 0;
+      w2_0_real = 0;
+      if (config_data.debug_level > 0) {
+        gCatena.SafePrintf("%010d - Load_cell 2 is disabled\n", millis());
+      }
     }
   }
   else {
     if (config_data.debug_level > 0) {
-      gCatena.SafePrintf("%010d - HX711 LoadCell not ready.\n", millis());
+      gCatena.SafePrintf("%010d - LoadCell not ready.\n", millis());
     }
   }
 
   // Disable Power
   gCatena.poll();
-  digitalWrite(D10, LOW);
+  PowerdownScale();
 
   // Gewicht berechnen
-  weight_current32 = (int32_t)((((res.weight1 - config_data.cal_w1_0) / config_data.cal_w1_factor) + ((res.weight2 - config_data.cal_w2_0) / config_data.cal_w2_factor)) / 5.0);
+  weight_current32 = (int32_t)((((res.weight1 - w1_0_real) / config_data.cal_w1_factor) + ((res.weight2 - w2_0_real) / config_data.cal_w2_factor)) / 5.0);
+
   if (weight_current32 < 0) {
     weight_current32 = 0;
   } else if (weight_current32 > UINT16_MAX) {
@@ -642,6 +598,10 @@ void ReadSensors(SENSOR_data &sensor_data) {
     // we set the weight to 0, as such high values are not realistic and probably a sign for bad calibration...
     weight_current32 = 0;
   }
+  if (config_data.cal_w1_0 == NOT_ATTACHED || config_data.cal_w2_0 == NOT_ATTACHED) {
+    // when at least one load cell is disabled, we multiply the measured weight by 2
+    weight_current32 = weight_current32 * 2;
+  }
   res.weight = (uint16_t)weight_current32;
 
   if (fBme) {
@@ -1231,7 +1191,7 @@ static void receiveMessage(void *pContext, uint8_t port, const uint8_t *pMessage
 
       config_data.cal_w1_0 = cal_w1_0;
       config_data.cal_w2_0 = cal_w2_0;
-      gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+      gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
       lora_data_first.cal_w1_0 = config_data.cal_w1_0;
       lora_data_first.cal_w2_0 = config_data.cal_w2_0;
     }
@@ -1247,7 +1207,7 @@ static void receiveMessage(void *pContext, uint8_t port, const uint8_t *pMessage
       config_data.cal_w2_0 = cal_w2_0;
       config_data.cal_w1_factor = cal_w1_factor;
       config_data.cal_w2_factor = cal_w2_factor;
-      gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+      gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
 
       lora_data_first.cal_w1_0 = config_data.cal_w1_0;
       lora_data_first.cal_w2_0 = config_data.cal_w2_0;
@@ -1315,8 +1275,8 @@ cCommandStream::CommandStatus cmdGetScale2(cCommandStream *pThis, void *pContext
 cCommandStream::CommandStatus cmdCalibrateZeroScaleA(cCommandStream *pThis, void *pContext, int argc, char **argv)
 {
   setup_scales();
-  config_data.cal_w1_0 = (int32_t)my_read_average(32, 10);
+  config_data.cal_w1_0 = (int32_t)ReadScale('A');
-  gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+  gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
   pThis->printf("{ \"msg\": \"calibrate_zero_scale_a was successful\" }\n");
 
   return cCommandStream::CommandStatus::kSuccess;
@@ -1325,8 +1285,8 @@ cCommandStream::CommandStatus cmdCalibrateZeroScaleA(cCommandStream *pThis, void
 cCommandStream::CommandStatus cmdCalibrateZeroScaleB(cCommandStream *pThis, void *pContext, int argc, char **argv)
 {
   setup_scales();
-  config_data.cal_w2_0 = (int32_t)my_read_average(128, 10);
+  config_data.cal_w2_0 = (int32_t)ReadScale('B');
-  gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+  gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
   pThis->printf("{ \"msg\": \"calibrate_zero_scale_b was successful\" }\n");
 
   return cCommandStream::CommandStatus::kSuccess;
@@ -1336,11 +1296,18 @@ cCommandStream::CommandStatus cmdCalibrateScaleA(cCommandStream *pThis, void *pC
 {
   String w1_gramm(argv[1]);
   long weight1;
-  setup_scales();
-  weight1 = my_read_average(32, 10);
-  config_data.cal_w1_factor = (float)((weight1 - config_data.cal_w1_0) / w1_gramm.toFloat());
 
-  gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+  if (w1_gramm == "NA") {
+    // scale a is not connected
+    config_data.cal_w1_factor = 1.0;
+    config_data.cal_w1_0 = NOT_ATTACHED;
+  } else {
+    setup_scales();
+    weight1 = ReadScale('A');
+    config_data.cal_w1_factor = (float)((weight1 - config_data.cal_w1_0) / w1_gramm.toFloat());
+  }
+
+  gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
 
   pThis->printf("{ \"msg\": \"calibrate_scale_a was successful\" }\n");
 
@@ -1351,11 +1318,18 @@ cCommandStream::CommandStatus cmdCalibrateScaleB(cCommandStream *pThis, void *pC
 {
   String w2_gramm(argv[1]);
   long weight2;
-  setup_scales();
-  weight2 = my_read_average(128, 10);
-  config_data.cal_w2_factor = (float)((weight2 - config_data.cal_w2_0) / w2_gramm.toFloat());
 
-  gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+  if (w2_gramm == "NA") {
+    // scale b is not connected
+    config_data.cal_w2_factor = 1.0;
+    config_data.cal_w2_0 = NOT_ATTACHED;
+  } else {
+    setup_scales();
+    weight2 = ReadScale('B');
+    config_data.cal_w2_factor = (float)((weight2 - config_data.cal_w2_0) / w2_gramm.toFloat());
+  }
+
+  gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
 
   pThis->printf("{ \"msg\": \"calibrate_scale_b was successful\" }\n");
 
@@ -1366,7 +1340,7 @@ cCommandStream::CommandStatus cmdSetDebugLevel(cCommandStream *pThis, void *pCon
 {
   String s_debug_level(argv[1]);
   config_data.debug_level = s_debug_level.toInt();
-  gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+  gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
 
   pThis->printf("{ \"msg\": \"set_debug_level was successful\" }\n");
 
@@ -1375,7 +1349,7 @@ cCommandStream::CommandStatus cmdSetDebugLevel(cCommandStream *pThis, void *pCon
 
 cCommandStream::CommandStatus cmdGetDebugLevel(cCommandStream *pThis, void *pContext, int argc, char **argv)
 {
-  gCatena.getFram()->saveField(cFramStorage::kBme680Cal, (const uint8_t *)&config_data, sizeof(config_data));
+  gCatena.getFram()->saveField(cFramStorage::kAppConf, (const uint8_t *)&config_data, sizeof(config_data));
 
   pThis->printf("{ \"msg\": \"debug_level is %d\" }\n", config_data.debug_level);
 

mini_beieli_node.h

@@ -56,7 +56,7 @@ enum {
   |
   \****************************************************************************/
 
-static const int32_t fwVersion = 20200211;
+static const int32_t fwVersion = 20200513;
 
 static const byte INIT_PACKAGE_INTERVAL = 100;  // send an init package every 100 packages;
 static const byte MAX_VALUES_TO_SEND = 8;
@@ -65,15 +65,16 @@ static const uint8_t LORA_DATA_VERSION = 1;
 static const uint8_t LORA_DATA_VERSION_FIRST_PACKAGE = 128;
 static const uint32_t PRESSURE_OFFSET = 825;
 static const uint16_t SEND_DIFF_THRESHOLD_5GRAMS = 10;   // when weight value drops by 50g, then send data
+static const long NOT_ATTACHED = -2147483648;
 
-// must be 139 bytes long (size of kBme680Cal)
+// must be 64 bytes long (size of kAppConf)
 typedef struct {
-  long cal_w1_0;                                     // 4 Bytes, Wert Waegezelle 1 ohne Gewicht
+  long cal_w1_0;                                     // 4 Bytes, Wert Waegezelle 1 ohne Gewicht, LONG_MIN when not connected
-  long cal_w2_0;                                     // 4 Bytes, Wert Waegezelle 2 ohne Gewicht
+  long cal_w2_0;                                     // 4 Bytes, Wert Waegezelle 2 ohne Gewicht, LONG_MIN when not connected
   float cal_w1_factor;                               // 4 Bytes, Kalibrationsfaktor Waegezelle 1
   float cal_w2_factor;                               // 4 Bytes, Kalibrationsfaktor Waegezelle 2
   byte debug_level;                                  // 0 => no debugging, no led, 1 => infos, no led, 2 => infos, 3 => error, 4 => highest level
-  byte fill[122];
+  byte fill[47];
 } __attribute__((packed)) CONFIG_data;
 
 typedef struct {

mini_beieli_node_hx711.h

@@ -0,0 +1,89 @@
+#define SAMPLES 10
+
+#include <Q2HX711.h>
+
+#ifndef _HELPER_H_
+#include "helper.h"
+#endif
+
+// Scales
+Q2HX711 hx711(A1, A0);
+
+byte debug_level;
+
+bool SetupScales(byte dbg_level)
+{
+  debug_level = dbg_level;
+  if (debug_level > 0) {
+    gCatena.SafePrintf("%010d - setup_scales\n", millis());
+  }
+
+  bool res;
+  res = true;
+
+  // Use D10 to regulate power
+  pinMode(D10, OUTPUT);
+
+  if (debug_level > 0) {
+    gCatena.SafePrintf("%010d - setup_scale done\n", millis());
+  }
+
+  return res;
+}
+
+long ReadScale(char channel)
+{
+  if (channel == 'B') {
+    hx711.setGain(128);
+  } else {
+    hx711.setGain(32);
+  }
+  delay(500);
+
+  long res;
+  int const num_scale_readings = 25; // number of instantaneous scale readings to calculate the median
+
+  // we use the median, not the average, see https://community.particle.io/t/boron-gpio-provides-less-current-than-electrons-gpio/46647/13
+  long readings[num_scale_readings];  // create arry to hold readings
+
+  if (debug_level > 0) {
+    gCatena.SafePrintf("%010d - my_read_average, measurements:\n", millis());
+  }
+
+  for (int i = 0; i < num_scale_readings; i++) {
+    readings[i] = hx711.read();  // fill the array with instantaneous readings from the scale
+    if (debug_level > 1) {
+      gCatena.SafePrintf("Reading %d: %d\n", i, readings[i]);
+    }
+  }
+
+  res = median(readings, num_scale_readings); // calculate median
+
+  if (debug_level > 0) {
+    gCatena.SafePrintf("Median of %d samples: %d\n", num_scale_readings, res);
+    float sdev;
+    sdev = stddev(readings, num_scale_readings);
+    gCatena.SafePrintf("Standard Deviation: %d.%03d\n", (int)sdev, (int)abs(sdev * 1000) % 1000);
+  }
+
+  return res;
+}
+
+void PowerdownScale()
+{
+  // Disable Power
+  digitalWrite(D10, LOW);
+}
+
+void PowerupScale()
+{
+  // Enable Power
+  digitalWrite(D10, HIGH);
+
+  // we wait 400ms (settling time according HX711 datasheet @ 10 SPS
+  delay(400);
+
+  if (debug_level > 0) {
+    gCatena.SafePrintf("%010d - setup_scale done\n", millis());
+  }
+}

mini_beieli_node_nau7802.h

@@ -0,0 +1,99 @@
+#include <Wire.h>
+
+#ifndef _HELPER_H_
+#include "helper.h"
+#endif
+
+#include "SparkFun_Qwiic_Scale_NAU7802_Arduino_Library.h"
+
+#define SAMPLES 10
+
+NAU7802 myScale; //Create instance of the NAU7802 class
+
+byte debug_level;
+
+byte interruptPin = A0;
+
+bool SetupScales(byte dbg_level)
+{
+  debug_level = dbg_level;
+
+  pinMode(interruptPin, INPUT);
+  Wire.begin();
+
+  if (!myScale.begin())
+  {
+    Serial.println("Scale not detected. Please check wiring. Freezing...");
+    return false;
+  }
+  Serial.println("Scale detected!");
+
+  myScale.setIntPolarityHigh();
+  delay(500);
+
+  return true;
+}
+
+long ReadScale(char channel)
+{
+  uint8_t channelNumber;
+  if (channel == 'B') {
+    channelNumber = NAU7802_CHANNEL_1;
+  } else {
+    channelNumber = NAU7802_CHANNEL_2;
+  }
+  long startTime = millis();
+  myScale.setChannel(channelNumber);
+  myScale.clearBit(NAU7802_PGA_PWR_PGA_CAP_EN, NAU7802_PGA_PWR);
+  myScale.setSampleRate(NAU7802_SPS_10);
+  myScale.setLDO(NAU7802_LDO_2V7);
+  myScale.calibrateAFE();
+  //delay(500);
+
+  long res;
+  int const num_scale_readings = SAMPLES; // number of instantaneous scale readings to calculate the median
+
+  // we use the median, not the average, see https://community.particle.io/t/boron-gpio-provides-less-current-than-electrons-gpio/46647/13
+  long readings[num_scale_readings];  // create arry to hold readings
+
+  for (int i = 0; i < num_scale_readings; i++) {
+    while (digitalRead(interruptPin) == LOW) {
+      //while(! myScale.available()) {
+      // we set a timeout of 60 seconds for the measurement...
+      if ((millis() - startTime) > 60000) {
+        if (debug_level > 0) {
+          gCatena.SafePrintf("Timeout while reading scale...\n");
+        }
+        return 0;
+      }
+      delay(1);
+    }
+    readings[i] = myScale.getReading();  // fill the array with instantaneous readings from the scale
+  }
+
+  long duration = millis() - startTime;
+  res = median(readings, num_scale_readings); // calculate median
+
+  if (debug_level > 0) {
+    gCatena.SafePrintf("Median of %d samples: %d\n", num_scale_readings, res);
+    float sdev;
+    sdev = stddev(readings, num_scale_readings);
+    float sdev_proc;
+    sdev_proc = 100 * (sdev / float(res));
+    gCatena.SafePrintf("Standard Deviation: %d.%03d\n", (int)sdev, (int)abs(sdev * 1000) % 1000);
+    gCatena.SafePrintf("Standard Deviation / Median (Percent): %d.%03d\n", (int)sdev_proc, (int)abs(sdev_proc * 1000) % 1000);
+    gCatena.SafePrintf("Duration (ms): %d\n", duration);
+  }  
+
+  return res;
+}
+
+void PowerdownScale()
+{
+  myScale.powerDown();
+}
+
+void PowerupScale()
+{
+  myScale.powerUp(); //Power up scale. This scale takes ~600ms to boot and take reading.
+}