tested with MCU and MCU S2

examples/serial-test/serial-test.ino

@@ -1,32 +1,36 @@
-#include <SolarCharger.h>
+#include <SolarChargerSB041.h>
 #include <Wire.h>
+// #include <senseBoxIO.h> // only needer fo senseBox MCU
 
-SolarCharger solar;
+SolarChargerSB041 charger;
 
 void setup() {
   Wire.begin();
   Serial.begin(9600);
 }
 
 void loop() {
-  solar.update();
+  charger.update();
 
-  if (solar.isConnected()) {
-    Serial.print("Solar Panel Voltage: ");
-    Serial.println(solar.getSolarPanelVoltage());
-    Serial.print("Battery Voltage: ");
-    Serial.println(solar.getBatteryVoltage());
-    Serial.print("Battery Level: ");
-    Serial.println(solar.getBatteryLevel());
-    Serial.print("Charging: ");
-    Serial.println(solar.isCharging() ? "Yes" : "No");
-    Serial.print("Fast Charging: ");
-    Serial.println(solar.isFastCharging() ? "Yes" : "No");
-    Serial.print("Battery Temperature: ");
-    Serial.println(solar.getBatteryTemperature());
-  } else {
-    Serial.println("Solar charger not connected.");
-  }
+  Serial.print("Charger Connected: ");
+  Serial.println(charger.isChargerConnected() ? "true" : "false");
+  Serial.print("Solar Panel Voltage: ");
+  Serial.println(charger.getSolarPanelVoltage());
+  Serial.print("Battery Voltage: ");
+  Serial.println(charger.getBatteryVoltage());
+  Serial.print("Charging: ");
+  Serial.println(charger.isCharging() ? "true" : "false");
+  Serial.print("Fast Charging: ");
+  Serial.println(charger.isFastCharging() ? "true" : "false");
+  Serial.print("Battery Level: ");
+  Serial.println(charger.getBatteryLevel());
+  Serial.print("Good Input Voltage: ");
+  Serial.println(charger.isGoodInputVoltage() ? "true" : "false");
+  Serial.print("Battery Present: ");
+  Serial.println(charger.isBatteryPresent() ? "true" : "false");
+  Serial.print("Battery Temperature: ");
+  Serial.println(charger.getBatteryTemperature());
+  Serial.println();
 
   delay(1000);
 }

library.properties

@@ -1,9 +1,9 @@
 name=SolarChargerSB041
 version=1.0.0
-author=Dein Name
-maintainer=Dein Name <[email protected]>
-sentence=Eine Arduino-Bibliothek für das Auslesen des Solarladereglers SB-041.
-paragraph=Diese Bibliothek ermöglicht das einfache Auslesen von Daten wie Batterie- und Solarpanel-Spannung, Ladezustand und Temperatur.
+author=Björn Luig
+maintainer=Björn Luig
+sentence=Library to read data from the SB041 solar charger designed for the senseBox. 
+paragraph=This library enables easy reading of data such as battery and solar panel voltage, charge status, and temperature.
 category=Sensors
-url=https://github.com/dein-repo
+url=https://github.com/sensebox/SolarChargerSB041
 architectures=*

src/SolarChargerSB041.cpp

@@ -1,30 +1,53 @@
 #include "SolarChargerSB041.h"
 
+#include "Arduino.h"
+
 SolarChargerSB041::SolarChargerSB041(uint8_t address)
     : address(address),
-      connected(false),
+      chargerConnected(false),
       solarPanelVoltage(-1),
       batteryVoltage(-1),
-      batteryLevel(-1),
       charging(false),
       fastCharging(false),
+      batteryLevel(-1),
+      goodInputVoltage(false),
+      batteryPresent(false),
       batteryTemperature(-1) {}
 
+/*
+ * I2C i/f with following info on address 0x32:
+ * - Register 0: cell voltage, 20mV/LSB
+ * - Register 1: input voltage, 100mV/LSB
+ * - Register 2: status bits: [B,I,L3,L2,L1,L0,F,C]
+ *    B=battery present >2.8V
+ *    I=Input voltage present >4.5V
+ *    L0-L3=battery status LEDs
+ *    F=Fast charge enabled
+ *    C=Charging
+ * - Register 3: temperature in C, signed 8-bit
+ * Thresholds: L0: 3.2V, L1: 3.6V, L2: 3.7V, L3: 3.9V
+ * Switch to slow charge at 8*C
+ * Switch to fast charge at 12*C
+ */
 void SolarChargerSB041::update() {
   Wire.beginTransmission(address);
   byte error = Wire.endTransmission();
-  if (error == 0 || error == 2) {
-    connected = (error == 0);
+  if (error == 0) {
+    chargerConnected = true;
     Wire.requestFrom((uint8_t)address, (uint8_t)4);
 
-    uint8_t vbat_raw = Wire.read();
-    batteryVoltage = 0.02 * vbat_raw;
+    // scale battery voltage
+    uint8_t batteryVoltageRaw = Wire.read();
+    batteryVoltage = 0.02 * batteryVoltageRaw;
 
+    // scale panel voltage
     uint8_t vin_raw = Wire.read();
     solarPanelVoltage = 0.1 * vin_raw;
 
+    // status flags
     uint8_t flags = Wire.read();
     charging = flags & 1;
+    fastCharging = flags & 2;
     if (flags & 32)
       batteryLevel = 4;
     else if (flags & 16)
@@ -35,30 +58,34 @@ void SolarChargerSB041::update() {
       batteryLevel = 1;
     else
       batteryLevel = 0;
+    goodInputVoltage = flags & 64;
+    batteryPresent = flags & 128;
 
-    fastCharging = flags & 64;
-    charging = flags & 128;
-
+    // battery temperature
     batteryTemperature = (int8_t)(Wire.read());
   } else {
-    connected = false;
-    fastCharging = false;
-    charging = false;
+    chargerConnected = false;  // or worse error
     batteryVoltage = -1;
     solarPanelVoltage = -1;
+    charging = false;
+    fastCharging = false;
     batteryLevel = -1;
+    goodInputVoltage = false;
+    batteryPresent = false;
     batteryTemperature = -1;
   }
 }
 
-bool SolarChargerSB041::isConnected() const { return connected; }
+bool SolarChargerSB041::isChargerConnected() const { return chargerConnected; }
 float SolarChargerSB041::getSolarPanelVoltage() const {
   return solarPanelVoltage;
 }
 float SolarChargerSB041::getBatteryVoltage() const { return batteryVoltage; }
-int SolarChargerSB041::getBatteryLevel() const { return batteryLevel; }
 bool SolarChargerSB041::isCharging() const { return charging; }
 bool SolarChargerSB041::isFastCharging() const { return fastCharging; }
+int SolarChargerSB041::getBatteryLevel() const { return batteryLevel; }
+bool SolarChargerSB041::isGoodInputVoltage() const { return goodInputVoltage; }
+bool SolarChargerSB041::isBatteryPresent() const { return batteryPresent; }
 float SolarChargerSB041::getBatteryTemperature() const {
   return batteryTemperature;
 }

src/SolarChargerSB041.h

@@ -1,60 +1,42 @@
-#ifndef SOLARCHARGER_H
-#define SOLARCHARGER_H
+/*
+  SolarChargerSB041.h - Library to read data from the SB041 solar charger
+  designed for the senseBox. Created by Björn Luig, Dec. 6, 2024. Released into
+  the public domain.
+*/
 
-#include <Wire.h>
-
-class SolarCharger {
- public:
-  SolarCharger(uint8_t address = 0x32);
-#ifndef SOLARCHARGER_H
-#define SOLARCHARGER_H
+#ifndef SOLARCHARGERSB041_H
+#define SOLARCHARGERSB041_H
 
 #include <Wire.h>
 
-      class SolarCharger {
-   public:
-    SolarCharger(uint8_t address = 0x32);
-
-    void update();
-    bool isConnected() const;
-    float getSolarPanelVoltage() const;
-    float getBatteryVoltage() const;
-    int getBatteryLevel() const;
-    bool isCharging() const;
-    bool isFastCharging() const;
-    float getBatteryTemperature() const;
-
-   private:
-    uint8_t address;
-    bool connected;
-    float solarPanelVoltage;
-    float batteryVoltage;
-    int batteryLevel;
-    bool charging;
-    bool fastCharging;
-    float batteryTemperature;
-  };
+#include "Arduino.h"
 
-#endif  // SOLARCHARGER_H
+class SolarChargerSB041 {
+ public:
+  SolarChargerSB041(uint8_t address = 0x32);
 
   void update();
-  bool isConnected() const;
+  bool isChargerConnected() const;
   float getSolarPanelVoltage() const;
   float getBatteryVoltage() const;
-  int getBatteryLevel() const;
   bool isCharging() const;
   bool isFastCharging() const;
+  int getBatteryLevel() const;
+  bool isGoodInputVoltage() const;
+  bool isBatteryPresent() const;
   float getBatteryTemperature() const;
 
  private:
   uint8_t address;
-  bool connected;
+  bool chargerConnected;
   float solarPanelVoltage;
   float batteryVoltage;
-  int batteryLevel;
   bool charging;
   bool fastCharging;
+  int batteryLevel;
+  bool goodInputVoltage;
+  bool batteryPresent;
   float batteryTemperature;
 };
 
-#endif  // SOLARCHARGER_H
+#endif  // SOLARCHARGERSB041_H