/* This is an amp limit controller for the Midnite Classic Charge Controller equipped with a WhizBangJr. It controls the amps flowing to the batteries (as measured by the WBJr) by altering the Classic amps out setpoint limit. The WBJr and Classic amps limits are both constrained High and Low. The maximum WBJr amps to the batteries and to the Classic are both adjusted by their setpoints. The Modbusmaster writes to the Classic only when the PID is turned on which allows manual adjustment of the Classic amp limiter if desired. The manual limit will be overriden by the controller when it turns on.The WBJr amp flow is smoothed with an array which is adjustable for the number of readings desired to be averaged.*/ #include #include #include #include // SCL Mega pin 21, Uno pin D16 ; SDA Mega pin 20 , Uno pin D17 double inputAmpsToBatt; double aveInputAmpsToBatt = 30; // smoothed wbjr average input amps to battery int actualAmpLimitSP; int inUseAmpLimitSetPoint; float ampOutputCalc = 0; // variable for amp PID output % calculation int spAmpLimit; // variable for display removes decimal double ClassicAmpSetPoint; // variable setpoint value written to Classic boolean pidAmpMode; double WBJrAmpLimitSP = 0; int ClassicHiAmpLimit = 0; //-------------------------------------------------------------------------smoothing wbjr amps to battery #define numReadings 25 double wbjrReadings[numReadings]; // the array for readings from wbjr amps to battery int index = 0; // the index of the current reading double total = 0; // the running total double average = 0; // the average //--------------------------------------------------------------------------------------------------control panel double WBJRAmpLimitSP = 70; // Hi amp limit to batteries (WBJr) setpoint int constrainWBJrLimitLo = 10; // constrains WBJr amp limit setpoint to low value int constrainWBJrLimitHi = 75; // constrains WBJr amp limit setpoint to high value int ClassicHIAmpLimitSP = 75; // Hi amp limit to Classic setpoint int constrainClscLimitLo = 5; // constrains Classic amp limit setpoint to low value int constrainClscLimitHi = 80; // constrains Classic amp limit setpoint to high value //--------------------------------------------------------------------------------------------------PID define Variables double ampInput; //pid input double ampOutput; //pid output //--------------------------------------------------------------------------------------------------PID tuning parameters #define Kp 2 #define Ki .30 #define Kd .03 PID ampPID(&Input, &Output, &WBJrAmpLimitSP, Kp, Ki, Kd, REVERSE); //--------------------------------------------------------------------------------------------------rs232 #define baud 19200 #define timeout 1500 #define polling 200 // the scan rate #define retry_count 20 #define TxEnablePin 2 // used to toggle the receive/transmit pin on the driver enum { PACKET1, PACKET2, PACKET3, PACKET4, PACKET5, TOTAL_NO_OF_PACKETS // leave this last entry }; Packet packets[TOTAL_NO_OF_PACKETS]; // Create an array of Packets to be configured packetPointer packet1 = &packets[PACKET1]; // Create a packetPointer to access each packet packetPointer packet2 = &packets[PACKET2]; packetPointer packet3 = &packets[PACKET3]; packetPointer packet4 = &packets[PACKET4]; packetPointer packet5 = &packets[PACKET5]; unsigned int readRegsd[3]; unsigned int readRegse[3]; unsigned int writeRegse[3]; unsigned int readRegsc[3]; unsigned int readRegsa[3]; //----------------------------------------------------------------------------------------------------------- LiquidCrystal_I2C lcd1(0X20, 20, 4); // set the LCD address to 0X20 for a 20 chars and 4 line display for lcd 1 //----------------------------------------------------------------------------------------------------------setup void setup() { lcd1.init (); // lcd setUp LCD1 display lcd1.backlight (); lcd1.display (); //------------------------------------------------------------------------------------------------------------- modbus_construct(packet1, 10, READ_HOLDING_REGISTERS, 4370, 1, readRegsd); // read 1 register wbjr amps to batt 4371 modbus_construct(packet2, 10, READ_HOLDING_REGISTERS, 4147, 1, readRegse); // read 1 register Classic battery amp in load limit setpoint 4148 modbus_construct(packet3, 10, PRESET_MULTIPLE_REGISTERS, 4147, 1, writeRegse); // write Classic amp in load limit register reg 4148 modbus_construct(packet4, 10, READ_HOLDING_REGISTERS, 4119, 1, readRegsc); // read 1 register Classic Charge State 4120 modbus_construct(packet5, 10, READ_HOLDING_REGISTERS, 4129, 1, readRegsa); // read 1 register Classic Charge State 4120 modbus_configure(&Serial, baud, SERIAL_8N1, timeout, polling, retry_count, TxEnablePin, packets, TOTAL_NO_OF_PACKETS); // Initialize communication settings: packets[PACKET3].connection = 0; // turns packet3 write connection off //---------------------------------------------------------------------------------------------------------- //initialize the PID in off state - 0 output ampPID.SetMode(MANUAL); ampPID.SetOutputLimits(0, 255); ampOutput = 0; pidAmpMode = false; lcd1.setCursor (16, 0); lcd1.print ("Off"); //------------------------------------------------------------------------------------------------------- // constrains Classic and WBJr amp limits; displays limits with constrained values WBJrAmpLimitSP = WBJRAmpLimitSP; spAmpLimit = (int) WBJrAmpLimitSP; // for display - cast as int to remove decimal points WBJrAmpLimitSP = constrain (WBJrAmpLimitSP, constrainWBJrLimitLo, constrainWBJrLimitHi); if (WBJRAmpLimitSP > constrainWBJrLimitHi) { // for display - prints actual limit values in use lcd1.setCursor (7, 2); lcd1.print (constrainWBJrLimitHi); } else if (WBJRAmpLimitSP < constrainWBJrLimitLo) { lcd1.setCursor (7, 2); lcd1.print (constrainWBJrLimitLo); } else { lcd1.setCursor (7, 2); lcd1.print (spAmpLimit); } ClassicHiAmpLimit = ClassicHIAmpLimitSP; ClassicHiAmpLimit = constrain (ClassicHiAmpLimit, constrainClscLimitLo, constrainClscLimitHi); if (ClassicHIAmpLimitSP > constrainClscLimitHi) { // for display - prints actual limit values in use lcd1.setCursor (7, 3); lcd1.print (constrainClscLimitHi); } else if (ClassicHIAmpLimitSP < constrainClscLimitLo) { lcd1.setCursor (7, 3); lcd1.print (constrainClscLimitLo); } else { lcd1.setCursor (7, 3); lcd1.print (ClassicHiAmpLimit); } } //--------------------------------------------------------------------------------------------------------loop void loop() { int state ; int ampLimitState; modbus_update(); // rs 232 read the Classic's modbus registers state = (unsigned int)readRegsc[0] >> 8; // high byte contains charge state code ampLimitState = (unsigned int)readRegsa[0] <<9; // 10th bit to the right has`amp limit reached bit actualAmpLimitSP = readRegse[0]; inUseAmpLimitSetPoint = actualAmpLimitSP; inUseAmpLimitSetPoint /= 10; //-----------------------------------------------------------------------------------------------------------------rs232 retry checking /*errorRegs[0] = packet1-> retries; // retry count from packet1 lcd1.setCursor (0,3); lcd1.print("Retries"); lcd1.setCursor (9,3); lcd1.print (errorRegs[0]); */ //-----------------------------------------------------------------------------------------------------------------wbjr amps to battery with smoothing inputAmpsToBatt = (signed int)readRegsd[0]; //wbjr amps to battery reg 4371 inputAmpsToBatt /= 10 ; total = total - wbjrReadings[index]; wbjrReadings[index] = inputAmpsToBatt; // read from the wbjr total = total + wbjrReadings[index]; // add the reading to the total: index = index + 1; // increment by 1 if (index >= numReadings) // if array full index = 0; // restart average = (double) total / numReadings; // calculate the average: aveInputAmpsToBatt = average; delay (2); //delay between reads for stability ampInput = aveInputAmpsToBatt; // input to PID is WBJr average amps to battery //------------------------------------------------------------------------------------- lcd1.setCursor(0, 0); // top line of lcd1 switch (state) { case 0: lcd1.print ("Resting "); ampPID.SetMode(MANUAL); //Manual when in resting ampOutput = 0; // Output"locks" at existing when on manual. This line sets output to zero lcd1.setCursor (16, 0); lcd1.print ("Off"); break; case 3: lcd1.print ("Absorb "); break; case 4: lcd1.print ("BulkMppt "); break; case 5: lcd1.print ("Float "); break; case 6: lcd1.print ("FloatMppt"); break; case 7: lcd1.print ("Equalize "); break; case 10: lcd1.print ("HyperVoc "); ampPID.SetMode(MANUAL); ampOutput = 0; lcd1.setCursor (17, 0); lcd1.print ("Off"); break; case 18: lcd1.print ("EqMppt "); break; } lcd1.setCursor (10, 0); //lcd1 lines 1,2,3&4 lcd1.print(ampLimitState); lcd1.setCursor (0, 1); //lcd1 lines 1,2,3&4 lcd1.print("WBJr BAmp"); lcd1.setCursor (15, 1); lcd1.print (aveInputAmpsToBatt); lcd1.setCursor (0, 2); lcd1.print ("WBJrSP"); lcd1.setCursor (12, 2); lcd1.print("%"); lcd1.setCursor(15, 2); lcd1.print(ampOutputCalc); lcd1.setCursor (0, 3); lcd1.print ("ClscSP"); lcd1.setCursor (11, 3); lcd1.print ("PidSP"); lcd1.setCursor (17, 3); lcd1.print (inUseAmpLimitSetPoint); //--------------------------------------------------------------------------------------------------PID computation & output % calculation ampPID.Compute(); ampOutputCalc = ampOutput; ampOutputCalc = ampOutputCalc /= 255; // convert controller output to % ampOutputCalc *= 100; // for display % output ClassicAmpSetPoint = ampOutputCalc; // output setpoint calc for Classic ClassicAmpSetPoint = ClassicAmpSetPoint /= 100; ClassicAmpSetPoint = 1 - ClassicAmpSetPoint; ClassicAmpSetPoint = ClassicAmpSetPoint * ClassicHiAmpLimit; // sets hi value for amps to Classic ClassicAmpSetPoint = ClassicAmpSetPoint *= 10; ClassicAmpSetPoint = (unsigned int) ClassicAmpSetPoint; if ((ampOutputCalc >= 1) && (pidAmpMode == true)) { lcd1.setCursor (16, 0); lcd1.print (" On"); packets[PACKET3].connection = 1; // turns packet3 write connection on writeRegse[0] = ClassicAmpSetPoint; modbus_update(); delay (5); } if ((ampInput < spAmpLimit) && ((inUseAmpLimitSetPoint + 1) == ClassicHiAmpLimit) && (pidAmpMode == true)) { packets[PACKET3].connection = 0; // turns packet3 write connection off modbus_update(); ampPID.SetMode(MANUAL); ampOutput = 0; lcd1.setCursor (16, 0); lcd1.print ("Off"); pidAmpMode = false; } if ((!(state == 0)) && (!(state == 10))) { // turns PID on if state is not resting or hypervoc ampPID.SetMode(AUTOMATIC); pidAmpMode = true; } }