Reduced RAM usage by using more flash strings

Now prints "finished sending request" only in debug mode
removed warning about random byte
solved balance state issues!

Author: ForrestFire0

BMS.cpp

@@ -19,7 +19,6 @@ bool BMS::requestResponse(uint16_t maxWait)
 {
     // Make sure any remaining data is flushed out.
     clear();
-    byte p;
 
     // Send the request
     BMSSerial->write(header, 2);
@@ -31,7 +30,9 @@ bool BMS::requestResponse(uint16_t maxWait)
     BMSSerial->write(outdata.checksumB);
     BMSSerial->write(end);
     BMSSerial->flush();
+#if BMS_DEBUG
     Serial.println("\nFinished sending request...");
+#endif
     delay(10);
 
     auto start = millis();
@@ -42,11 +43,13 @@ bool BMS::requestResponse(uint16_t maxWait)
         delay(10);
     }
 
-    p = next();
+    
 #if BMS_DEBUG
     Serial.print("Start: ");
-    printHex(p);
+    printHex(next());
     Serial.println();
+#else
+    next();
 #endif
 
     // Second byte echos command. Lets make sure it matches the original byte.
@@ -156,9 +159,9 @@ boolean BMS::update(uint16_t maxWait)
     outdata.checksumB = 0xFD;
     bool mainSuccess = requestResponse(maxWait);
 
-    if (cellSuccess)
+    if (mainSuccess)
     {
-        balanceState = ((uint32_t)indata.data[13]) << 24 | ((uint32_t)indata.data[14]) << 16 | ((uint32_t)indata.data[15]) << 8 | indata.data[16];
+        balanceState = ((uint32_t)indata.data[14]) << 24 | ((uint32_t)indata.data[15]) << 16 | ((uint16_t)indata.data[12]) << 8 | indata.data[13];
 
         uint16_t temp;
 
@@ -170,7 +173,7 @@ boolean BMS::update(uint16_t maxWait)
 
         if (indata.data[22] != NUM_TEMP_PROBES)
         {
-            Serial.print("Error: wrong number of temp probes found. Found: ");
+            Serial.print(F("Error: num of temp probes. Found: "));
             Serial.print(indata.data[22]);
         }
 
@@ -180,9 +183,8 @@ boolean BMS::update(uint16_t maxWait)
             probes[i] = (temp - 2731) / 10.00f;
         }
 
-        Serial.println(indata.data[20]);
-        MOSFETStatus.charge = !(indata.data[20] & (1 << 7));
-        MOSFETStatus.discharge = !(indata.data[20] & (1 << 6));
+        MOSFETStatus.charge = (indata.data[20] % 2) == 1;
+        MOSFETStatus.discharge = indata.data[20] >= 2;
     }
     else
     {
@@ -197,12 +199,12 @@ boolean BMS::checkStatus(byte status)
     switch (status)
     {
     case 0x80:
-        Serial.println("BMS returned fail code...");
+        Serial.println(F("BMS returned fail code..."));
         return false;
     case 0x00:
         return true;
     default:
-        Serial.println("BMS returned unknown code:");
+        Serial.println(F("BMS returned unknown code:"));
         Serial.println(status);
         return false;
     }

BMS.h

@@ -7,9 +7,11 @@
 #ifndef NUM_CELLS
 #define NUM_CELLS 21
 #endif
+
 #ifndef NUM_TEMP_PROBES
 #define NUM_TEMP_PROBES 4
 #endif
+
 #ifndef BMS_DEBUG
 #define BMS_DEBUG false
 #endif

examples/BasicRead/BasicRead.ino

@@ -3,60 +3,85 @@
     - Read the BMS cell voltages, pack voltage, and error codes.
 */
 
-
-#define BMS_RX_PIN 2 //pin the bms is reciving signals on, where we are sending.
-#define BMS_TX_PIN 3 //pin the BMS is sending signals to, where we are recieving.
+#define BMS_RX_PIN 2 //pin the bms is receiving signals on, where we are sending.
+#define BMS_TX_PIN 3 //pin the BMS is sending signals to, where we are receiving.
 #define NUM_CELLS 21
 #define NUM_TEMP_PROBES 4
+#define BMS_DEBUG false
+// Debug mode prints the hex of every byte coming in and leaving.
+// You can compare the bytes you receive to what you should be receiving on the google sheet linked at the bottom of the readme.
 
 #include <SoftwareSerial.h>
 #include <BMS.h>
 SoftwareSerial BMSSerial(BMS_TX_PIN, BMS_RX_PIN);
 BMS bms;
 
-void setup() {
+void setup()
+{
     Serial.begin(115200);
-    
+
     BMSSerial.begin(9600);
     bms.begin(&BMSSerial);
-    
+
     Serial.println("Finished setup");
 }
 
-void loop() {
-    
-    bms.update();
+void loop()
+{
 
+    bms.update();
     Serial.println("Voltages: (V)");
-    for (byte i = 0; i < NUM_CELLS; i++) {
+    for (byte i = 0; i < NUM_CELLS; i++)
+    {
         Serial.print(i + 1);
         Serial.print(F("   "));
-        if (i < 9) Serial.print(F(" "));
+        if (i < 9)
+            Serial.print(F(" "));
     }
     Serial.println();
-    float* cells = bms.getCells();
-    for (byte i = 0; i < NUM_CELLS; i++) {
+    float *cells = bms.getCells();
+    for (byte i = 0; i < NUM_CELLS; i++)
+    {
         Serial.print(cells[i], 2);
         Serial.print(F(" "));
     }
-    Serial.print("\nPack voltage: "); Serial.println(bms.getPackVoltage());
-    Serial.print("Min cell voltage: "); Serial.println(bms.getCellMinVoltage());
-    Serial.print("Max cell voltage: "); Serial.println(bms.getCellMaxVoltage());
-    Serial.print("Cell Diff: "); Serial.println(bms.getCellDiff());
+    Serial.println();
+    uint32_t balstate = bms.getBalanceState();
+    for (byte i = 0; i < NUM_CELLS; i++)
+    {
+        Serial.print(bitRead(balstate, i));
+        Serial.print(F("    "));
+    }
 
-    Serial.print("Balance State: "); Serial.println(bms.getBalanceState(), BIN);
-    Serial.println("Charge: "); Serial.println(bms.getMOSFETStatus().charge ? "Permitted" : "Prohibited");
-    Serial.println("Discharge: "); Serial.println(bms.getMOSFETStatus().discharge ? "Permitted" : "Prohibited");
+    Serial.print("\nPack voltage: ");
+    Serial.println(bms.getPackVoltage());
+    Serial.println("\nMax  Min  Average");
+    Serial.print(bms.getCellMaxVoltage());
+    Serial.print("   ");
+    Serial.print(bms.getCellMinVoltage());
+    Serial.print("   ");
+    Serial.println(bms.getPackVoltage() / NUM_CELLS);
+    Serial.print("Cell Diff: ");
+    Serial.println(bms.getCellDiff());
+
+    Serial.print("Charge: ");
+    Serial.println(bms.getMOSFETStatus().charge ? "Permitted" : "Prohibited");
+    Serial.print("Discharge: ");
+    Serial.println(bms.getMOSFETStatus().discharge ? "Permitted" : "Prohibited");
 
     Serial.println("Temps: (C)");
-    for (byte i = 0; i < NUM_TEMP_PROBES; i++) {
+    for (byte i = 0; i < NUM_TEMP_PROBES; i++)
+    {
         Serial.print(i + 1);
         Serial.print(F("     "));
     }
     Serial.println();
-    float* probes = bms.getProbeData();
-    for (byte i = 0; i < NUM_TEMP_PROBES; i++) {
+    float *probes = bms.getProbeData();
+    for (byte i = 0; i < NUM_TEMP_PROBES; i++)
+    {
         Serial.print(probes[i], 2);
         Serial.print(F(" "));
     }
+
+    delay(2000);
 }