Version 4.4.0 - Fixed ESR (Equivalent Series Resistor) computing bug; Fixed I2C global error handling; Improved optional info handling.

Author: ArminJo

README.md

@@ -26,6 +26,12 @@ Based on the unmaintained [PackProbe program](https://github.com/PowerCartel/Pac
 
 <br/>
 
+# Features
+- Incudes a combined volt / resistance meter, to determine the function of unknown SBM connections.
+- Starts with I2C address scanning.
+- Computing of pack ESR (Equivalent Series Resistor) if current changes from 0 to != 0 e.g. at start to charge or discharge.
+- Activating a discharge MOsFet, as long as voltages are above 3.3 volt per cell.
+- Reconnecting after I2C failure.
 
 # Disclaimer
 **I do not know how to enter full access mode, clear permanent failure or unlock any controller IC.** Unfortunately according to most datasheets, you need an unlock key.
@@ -140,36 +146,37 @@ Sample outputs can be found in folder [extras](https://github.com/ArminJo/Smart-
 
 ```
 START ../src/SBMInfo.cpp
-Version 4.3 from Nov 23 2023
+Version 4.4 from Oct  4 2025
 Configured to set charge control pin 9 to low above 95 %
-Configured to stop discharge control pin 10 to low below 5 % or 3300 mV
-Found attached I2C device at 0xB
+Configured to set discharge control pin 10 to low below 5 % or 3300 mV
+Found attached I2C device at address 0xB
 
 Battery mode                        0x6081 | 0b110000010000001
                                     - Internal Charge Controller Supported
                                     - Battery OK
                                     - Disable AlarmWarning broadcast to Host and Smart Battery Charger
                                     - Disable broadcasts of ChargingVoltage and ChargingCurrent to Smart Battery Charger
 
-Manufacturer Name                   DP-SDI51
-Chemistry                           LION
-Manufacturer Data                   0x6 7D B B1 67 14 96 D 0 C8 0 A9 2A 
-Device Name                         DAVOS
-Serial number                       55982 | 0xDAAE
+Value1=3687, Value2=3667 - Non standard info is supported
+Manufacturer Name                   SANYO | 0x53 41 4E 59 4F 
+Chemistry                           LION | 0x4C 49 4F 4E
+Manufacturer Data                   W'4=5 | 0x57 7 27 3 34 E 3D E 1F E 35 E 
+Device Name                         M10B1 | 0x4D 31 30 42 31 
+Serial number                       11444 | 0x2CB4
 Manufacture date (YYYY-MM-DD)       2008-5-25
-Design voltage                      10.800 V
-Design capacity                     5100 mAh
-Charging current                    3570 mA
-Charging voltage                    12.600 V
+Design voltage                      14.400 V | 4 cells
+Design capacity                     4400 mAh
+Charging current                    3080 mA
+Charging voltage                    16.800 V
 SBM protocol (Version / Revision)   1.1 with optional PEC support / 1
-Cycle count                         277
+Cycle count                         331
 
 Max error of charge calculation     100%
 Remaining time alarm                10 min
 Remaining capacity alarm            510 mAh
 
 *** MANUFACTURER INFO ***
-Device Type                         0 | 0x0
+Device Type                         1794 | 0x702
 
 *** RATE TEST INFO ***
 Setting AT rate to                  100 mA
@@ -201,31 +208,39 @@ Pack config and status              0x8230 | 0b1000001000110000
                                     - Discharge is qualified for capacity learning
 
 
-*** DYNAMIC NON STANDARD INFO ***
+*** DYNAMIC NON STANDARD INFO / Cell Voltages + SOH ***
 Cell 1 Voltage                      3.826 V
 Cell 2 Voltage                      3.823 V
 Cell 3 Voltage                      3.819 V
 Cell 4 Voltage                      0x0
+State of Health                     5911 | 0x1717
 
 *** CHANGED VALUES ***
 
---- Next values are from another Pack! I connected 22 ohm Resistor -> 699 mA discharging
+--- After onnecting the 100 ohm discharge resistor, ESR is computed!
 
-Voltage                             15.788 V
-Average current of last minute      -187 mA
-Average minutes remaining until empty: 15 h 24 min
-Cell 4 Voltage:                     3.935 V
-Voltage                             15.807 V
+Current                             -147 mA
+Voltage                             14.653 V
+Average current of last minute      -31 mA
+Minutes remaining until empty       1 min
+Average minutes remaining until empty  1 min
+Battery status (BIN)                0x3C0 | 0b1111000000
+                                    - REMAINING_CAPACITY_ALARM
+                                    - REMAINING_TIME_ALARM_FLAG
+                                    80 Initialized
+                                    40 Discharging
+
+Cell 1 Voltage                      3.666 V
+Cell 2 Voltage                      3.646 V
+Cell 3 Voltage                      3.674 V
+Cell 4 Voltage                      3.666 V
+Voltage                             14.650 V | ESR = 0.578 ohm
+Average current of last minute      -78 mA
+Cell 2 Voltage                      3.645 V
+Cell 3 Voltage                      3.673 V
+Average current of last minute      -104 mA
+Voltage                             14.648 V
 Average current of last minute      -120 mA
-Average minutes remaining until empty: 24 h 1 min
-Cell 4 Voltage:                     3.949 V
-Average current of last minute      -77 mA
-Average minutes remaining until empty: 37 h 25 min
-Voltage                             15.714 V
-Current                             -699 mA
-Average current of last minute      -178 mA
-Minutes remaining until empty       4 h 7 min
-Average minutes remaining until empty: 16 h 11 min
 ```
 
 <br/>
@@ -236,6 +251,11 @@ Average minutes remaining until empty: 16 h 11 min
 ![Fritzing schematics](extras/SBMInfo_Schaltplan.png)
 
 # Revision History
+### Version 4.4.0
+- Fixed ESR (Equivalent Series Resistor) computing bug.
+- Fixed I2C global error handling.
+- Improved optional info handling.
+
 ### Version 4.3.0
 - Fixed no voltage measurement bug.
 - Improved print and LCD display after I2C reconnection.

SBMInfo/ADCUtils.h

@@ -29,6 +29,9 @@
 #if defined(__AVR__) && defined(ADCSRA) && defined(ADATE) && (!defined(__AVR_ATmega4809__))
 #define ADC_UTILS_ARE_AVAILABLE
 
+// External Reference Current is 150 uA for 5 V and 100 uA for 3.5 V
+#define READING_FOR_AREF 1024L // Datasheet 24.2: The minimum value represents GND and the maximum value represents the voltage on the AREF pin minus 1 LSB
+
 // PRESCALE4 => 13 * 4 = 52 microseconds per ADC conversion at 1 MHz Clock => 19,2 kHz
 #define ADC_PRESCALE2    1 // 26 microseconds per ADC conversion at 1 MHz
 #define ADC_PRESCALE4    2 // 52 microseconds per ADC conversion at 1 MHz

SBMInfo/ADCUtils.hpp

@@ -27,11 +27,15 @@
 
 #include "ADCUtils.h"
 #if defined(ADC_UTILS_ARE_AVAILABLE) // set in ADCUtils.h, if supported architecture was detected
+#define ADC_UTILS_ARE_INCLUDED
 
-#if !defined(STR_HELPER)
+#if !defined(STR)
 #define STR_HELPER(x) #x
 #define STR(x) STR_HELPER(x)
 #endif
+#if !defined(BITS_PER_BYTE)
+#define BITS_PER_BYTE 8
+#endif
 
 /*
  * By replacing this value with the voltage you measured a the AREF pin after a conversion
@@ -58,11 +62,16 @@ union WordUnionForADCUtils {
  * Enable this to see information on each call.
  * Since there should be no library which uses Serial, it should only be enabled for development purposes.
  */
-#if defined(DEBUG) && !defined(LOCAL_DEBUG)
+#if defined(DEBUG)
 #define LOCAL_DEBUG
 #else
 //#define LOCAL_DEBUG // This enables debug output only for this file
 #endif
+#if defined(INFO)
+#define LOCAL_INFO
+#else
+//#define LOCAL_INFO // This enables debug output only for this file
+#endif
 
 /*
  * Persistent storage for VCC value
@@ -403,7 +412,7 @@ uint16_t readUntil4ConsecutiveValuesAreEqual(uint8_t aADCChannelNumber, uint8_t
         /*
          * Get min and max of the last 4 values
          */
-        tMin = 1024;
+        tMin = READING_FOR_AREF;
         tMax = 0;
         for (uint_fast8_t i = 0; i < 4; ++i) {
             if (tValues[i] < tMin) {
@@ -472,7 +481,7 @@ uint16_t readUntil4ConsecutiveValuesAreEqual(uint8_t aADCChannelNumber, uint8_t
 float getVCCVoltageSimple(void) {
     // use AVCC with (optional) external capacitor at AREF pin as reference
     float tVCC = readADCChannelMultiSamplesWithReference(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT, 4);
-    return ((1023 * 1.1 * 4) / tVCC);
+    return ((READING_FOR_AREF * 1.1 * 4) / tVCC);
 }
 
 /*
@@ -483,19 +492,19 @@ float getVCCVoltageSimple(void) {
 uint16_t getVCCVoltageMillivoltSimple(void) {
     // use AVCC with external capacitor at AREF pin as reference
     uint16_t tVCC = readADCChannelMultiSamplesWithReference(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT, 4);
-    return ((1023L * ADC_INTERNAL_REFERENCE_MILLIVOLT * 4) / tVCC);
+    return ((READING_FOR_AREF * ADC_INTERNAL_REFERENCE_MILLIVOLT * 4) / tVCC);
 }
 
 /*
  * Gets the hypothetical 14 bit reading of VCC using 1.1 volt reference
- * Similar to getVCCVoltageMillivolt() * 1023 / 1100
+ * Similar to getVCCVoltageMillivolt() * 1024 / 1100
  */
 uint16_t getVCCVoltageReadingFor1_1VoltReference(void) {
     uint16_t tVCC = waitAndReadADCChannelWithReference(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT);
     /*
      * Do not switch back ADMUX to enable checkAndWaitForReferenceAndChannelToSwitch() to work correctly for the next measurement
      */
-    return ((1023L * 1023L) / tVCC);
+    return ((READING_FOR_AREF * READING_FOR_AREF) / tVCC);
 }
 
 /*
@@ -519,7 +528,7 @@ uint16_t getVCCVoltageMillivolt(void) {
     /*
      * Do not switch back ADMUX to enable checkAndWaitForReferenceAndChannelToSwitch() to work correctly for the next measurement
      */
-    return ((1023L * ADC_INTERNAL_REFERENCE_MILLIVOLT) / tVCC);
+    return ((READING_FOR_AREF * ADC_INTERNAL_REFERENCE_MILLIVOLT) / tVCC);
 }
 
 /*
@@ -547,7 +556,7 @@ void readAndPrintVCCVoltageMillivolt(Print *aSerial) {
 void readVCCVoltageSimple(void) {
     // use AVCC with (optional) external capacitor at AREF pin as reference
     float tVCC = readADCChannelMultiSamplesWithReference(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT, 4);
-    sVCCVoltage = (1023 * (((float) ADC_INTERNAL_REFERENCE_MILLIVOLT) / 1000) * 4) / tVCC;
+    sVCCVoltage = (READING_FOR_AREF * (((float) ADC_INTERNAL_REFERENCE_MILLIVOLT) / 1000) * 4) / tVCC;
 }
 
 /*
@@ -558,7 +567,7 @@ void readVCCVoltageSimple(void) {
 void readVCCVoltageMillivoltSimple(void) {
     // use AVCC with external capacitor at AREF pin as reference
     uint16_t tVCCVoltageMillivoltRaw = readADCChannelMultiSamplesWithReference(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT, 4);
-    sVCCVoltageMillivolt = (1023L * ADC_INTERNAL_REFERENCE_MILLIVOLT * 4) / tVCCVoltageMillivoltRaw;
+    sVCCVoltageMillivolt = (READING_FOR_AREF * ADC_INTERNAL_REFERENCE_MILLIVOLT * 4) / tVCCVoltageMillivoltRaw;
 }
 
 /*
@@ -579,7 +588,7 @@ void readVCCVoltageMillivolt(void) {
     /*
      * Do not switch back ADMUX to enable checkAndWaitForReferenceAndChannelToSwitch() to work correctly for the next measurement
      */
-    sVCCVoltageMillivolt = (1023L * ADC_INTERNAL_REFERENCE_MILLIVOLT) / tVCCVoltageMillivoltRaw;
+    sVCCVoltageMillivolt = (READING_FOR_AREF * ADC_INTERNAL_REFERENCE_MILLIVOLT) / tVCCVoltageMillivoltRaw;
 }
 
 /*
@@ -588,7 +597,7 @@ void readVCCVoltageMillivolt(void) {
  */
 uint16_t getVoltageMillivolt(uint16_t aVCCVoltageMillivolt, uint8_t aADCChannelForVoltageMeasurement) {
     uint16_t tInputVoltageRaw = waitAndReadADCChannelWithReference(aADCChannelForVoltageMeasurement, DEFAULT);
-    return (aVCCVoltageMillivolt * (uint32_t) tInputVoltageRaw) / 1023;
+    return (aVCCVoltageMillivolt * (uint32_t) tInputVoltageRaw) / READING_FOR_AREF;
 }
 
 /*
@@ -597,16 +606,18 @@ uint16_t getVoltageMillivolt(uint16_t aVCCVoltageMillivolt, uint8_t aADCChannelF
  */
 uint16_t getVoltageMillivolt(uint8_t aADCChannelForVoltageMeasurement) {
     uint16_t tInputVoltageRaw = waitAndReadADCChannelWithReference(aADCChannelForVoltageMeasurement, DEFAULT);
-    return (getVCCVoltageMillivolt() * (uint32_t) tInputVoltageRaw) / 1023;
+    return (getVCCVoltageMillivolt() * (uint32_t) tInputVoltageRaw) / READING_FOR_AREF;
 }
 
 uint16_t getVoltageMillivoltWith_1_1VoltReference(uint8_t aADCChannelForVoltageMeasurement) {
     uint16_t tInputVoltageRaw = waitAndReadADCChannelWithReference(aADCChannelForVoltageMeasurement, INTERNAL);
-    return (ADC_INTERNAL_REFERENCE_MILLIVOLT * (uint32_t) tInputVoltageRaw) / 1023;
+    return (ADC_INTERNAL_REFERENCE_MILLIVOLT * (uint32_t) tInputVoltageRaw) / READING_FOR_AREF;
 }
 
 /*
  * Return true if sVCCVoltageMillivolt is > 4.3 V and < 4.95 V
+ * This does not really work for the UNO board, because it has no series Diode in the USB VCC
+ * and therefore a very low voltage drop.
  */
 bool isVCCUSBPowered() {
     readVCCVoltageMillivolt();
@@ -634,13 +645,13 @@ bool isVCCUSBPowered(Print *aSerial) {
 }
 
 /*
+ * It checks every 10 seconds for 6 times, and then returns true if the undervoltage condition ( <3.4V ) still applies.
  * @ return true only once, when VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP (6) times voltage too low -> shutdown
  */
 bool isVCCUndervoltageMultipleTimes() {
     /*
      * Check VCC every VCC_CHECK_PERIOD_MILLIS (10) seconds
      */
-
     if (millis() - sLastVCCCheckMillis >= VCC_CHECK_PERIOD_MILLIS) {
         sLastVCCCheckMillis = millis();
 
@@ -650,30 +661,32 @@ bool isVCCUndervoltageMultipleTimes() {
         readVCCVoltageMillivolt();
 #  endif
 
-        if (sVCCTooLowCounter < VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP) {
-            /*
-             * Do not check again if shutdown has happened
-             */
+        /*
+         * Do not check again if shutdown signaling (sVCCTooLowCounter >= 6) has happened
+         */
+        if (sVCCTooLowCounter < VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP) { // VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP = 6
             if (sVCCVoltageMillivolt > VCC_UNDERVOLTAGE_THRESHOLD_MILLIVOLT) {
                 sVCCTooLowCounter = 0; // reset counter
             } else {
                 /*
-                 * Voltage too low, wait VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP (6) times and then shut down.
+                 * Voltage too low, wait VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP (6) times and then signal shut down.
                  */
                 if (sVCCVoltageMillivolt < VCC_EMERGENCY_UNDERVOLTAGE_THRESHOLD_MILLIVOLT) {
                     // emergency shutdown
                     sVCCTooLowCounter = VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP;
-#  if defined(INFO)
+#  if defined(LOCAL_INFO)
                     Serial.println(
                             F(
-                                    "Voltage < " STR(VCC_EMERGENCY_UNDERVOLTAGE_THRESHOLD_MILLIVOLT) " mV detected -> emergency shutdown"));
+                                    "Undervoltage < " STR(VCC_EMERGENCY_UNDERVOLTAGE_THRESHOLD_MILLIVOLT) " mV detected -> emergency shutdown"));
 #  endif
                 } else {
                     sVCCTooLowCounter++;
-#  if defined(INFO)
-                    Serial.print(F("Voltage < " STR(VCC_UNDERVOLTAGE_THRESHOLD_MILLIVOLT) " mV detected: "));
+#  if defined(LOCAL_INFO)
+                    Serial.print(sVCCVoltageMillivolt);
+                    Serial.print(F(" mV < " STR(VCC_UNDERVOLTAGE_THRESHOLD_MILLIVOLT) " mV undervoltage detected: "));
+
                     Serial.print(VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP - sVCCTooLowCounter);
-                    Serial.println(F(" tries left"));
+                    Serial.println(F(" attempts left"));
 #  endif
                 }
                 if (sVCCTooLowCounter == VCC_UNDERVOLTAGE_CHECKS_BEFORE_STOP) {
@@ -815,4 +828,7 @@ float getVCCVoltage() {
 #if defined(LOCAL_DEBUG)
 #undef LOCAL_DEBUG
 #endif
+#if defined(LOCAL_INFO)
+#undef LOCAL_INFO
+#endif
 #endif // _ADC_UTILS_HPP

SBMInfo/LiquidCrystal.cpp

@@ -283,7 +283,7 @@ void LiquidCrystal::createChar(uint8_t location, uint8_t charmap[]) {
   for (int i=0; i<8; i++) {
     write(charmap[i]);
   }
-  command(LCD_SETDDRAMADDR); // set cursor to 0.0, this avoids overwriting CGRAM by next write() command.
+  // command(LCD_SETDDRAMADDR); // set cursor to 0.0, this avoids overwriting CGRAM by next write() command. Not contained anymore in the Arduino version
 }
 
 /*********** mid level commands, for sending data/cmds */
@@ -294,7 +294,7 @@ inline void LiquidCrystal::command(uint8_t value) {
 
 inline size_t LiquidCrystal::write(uint8_t value) {
   send(value, HIGH);
-  return 1; // assume sucess
+  return 1; // assume success
 }
 
 /************ low level data pushing commands **********/