/** * ========================================================================== * Blazej's Twizy Lead Acid "BMS" * ========================================================================== * * Hardware setup: * - Arduino Nano + NiRen MCP2515_CAN (16 MHz) + relay + power regulator * - HC-06 Bluetooth module (AltSoftSerial pin 8+9) * Sensors: * - 1x LM35D temperature sensor (PORT_TEMP) * - 4x voltage divider at 60/45/30/15 V (PORT_C1…4) * * Authors: * - Michael Balzer * - Błażej Błaszczyk * * Libraries used: * - TwizyVirtualBMS https://github.com/dexterbg/Twizy-Virtual-BMS * - MCP_CAN https://github.com/coryjfowler/MCP_CAN_lib * - FlexiTimer2 https://github.com/PaulStoffregen/FlexiTimer2 * - AltSoftSerial https://github.com/PaulStoffregen/AltSoftSerial * * License: * This is free software under GNU Lesser General Public License (LGPL) * https://www.gnu.org/licenses/lgpl.html * */ #define BLAZEJ_BMS_VERSION "V2.1.0 (2017-07-05)" #include "TwizyVirtualBMS_config.h" #include "TwizyVirtualBMS.h" #include "AltSoftSerial.h" #include "BlazejBMS_config.h" TwizyVirtualBMS twizy; // Bluetooth software serial port: // Note: AltSoftSerial uses fixed pins! // i.e. Arduino Nano: RX = pin 8, TX = pin 9 AltSoftSerial bt; // -------------------------------------------------------------------------- // State variables // float temp = 20.0; float vpack = VMAX_DRV; float c1 = VMAX_DRV / 4, c2 = VMAX_DRV / 4, c3 = VMAX_DRV / 4, c4 = VMAX_DRV / 4; float soc = 99.0; float curr = 0.0; int drvpwr = MAX_DRIVE_POWER; int recpwr = MAX_RECUP_POWER; int chgcur = MAX_CHARGE_CURRENT; unsigned long error = TWIZY_OK; // -------------------------------------------------------------------------- // Callback: handle state transition for BMS // - called by twizyEnterState() after Twizy handling // Note: avoid complex operations, this needs to be fast. // void bmsEnterState(TwizyState currentState, TwizyState newState) { // lower SOC at switch-on to prevent immediate charge stop: if (currentState == Init && newState == Ready) { if (soc > 99) { soc -= 1; twizy.setSOC(soc); twizy.setChargeCurrent(5); Serial.print(F("bmsEnterState: soc lowered to ")); Serial.println(soc, 1); } } } // -------------------------------------------------------------------------- // Callback: timer ticker // - called every 10 ms by twizyTicker() after twizy handling // - clockCnt cyclic range: 0 .. 2999 = 30 seconds (reset to 0 on Off/Init) // Note: avoid complex operations, this needs to be fast. // void bmsTicker(unsigned int clockCnt) { // full second? if (clockCnt % 100 != 0) { return; } if (twizy.state() != Off) { Serial.println(F("\nbmsTicker:")); error = TWIZY_OK; // ---------------------------------------------------------------------- // bmsTicker: Read stacked cell voltages // c1 = analogRead(PORT_C1) / 1024.0 * SCALE_C1; // 60 V c2 = analogRead(PORT_C2) / 1024.0 * SCALE_C2; // 45 V c3 = analogRead(PORT_C3) / 1024.0 * SCALE_C3; // 30 V c4 = analogRead(PORT_C4) / 1024.0 * SCALE_C4; // 15 V #if INPUT_CALIBRATION >= 1 // raw output for calibration: Serial.print(F("< raw c1 = ")); Serial.println(c1, 2); Serial.print(F("< c2 = ")); Serial.println(c2, 2); Serial.print(F("< c3 = ")); Serial.println(c3, 2); Serial.print(F("< c4 = ")); Serial.println(c4, 2); #endif // derive single cell voltages from stacked voltages: vpack = c1; c1 -= c2; c2 -= c3; c3 -= c4; // ---------------------------------------------------------------------- // bmsTicker: Derive SOC from voltage // // - newsoc = SOC in operation mode voltage range // - soc = smoothed operation mode SOC // (used to derive drive & recup power & charge current) // float newsoc; // voltage range depends on operation mode: if (twizy.state() == Charging) { newsoc = (vpack - VMIN_CHG) / (VMAX_CHG - VMIN_CHG) * 100.0; } else { newsoc = (vpack - VMIN_DRV) / (VMAX_DRV - VMIN_DRV) * 100.0; } // smooth... if (newsoc < soc) { // slow adaption to lower voltages: soc = ((soc * (SMOOTH_SOC_DOWN-1)) + newsoc) / SMOOTH_SOC_DOWN; } else { if (twizy.state() == Charging) { // fast adaption while charging: soc = ((soc * (SMOOTH_SOC_UP_CHG-1)) + newsoc) / SMOOTH_SOC_UP_CHG; } else { // slow adaption while driving: soc = ((soc * (SMOOTH_SOC_UP-1)) + newsoc) / SMOOTH_SOC_UP; } } // sanitize... soc = constrain(soc, 0.0, 100.0); // ---------------------------------------------------------------------- // bmsTicker: Derive power limits & charge current from SOC // // scale down drive power for low SOC: // 100% at FULL → 100% at → at → 0% at EMPTY #define SOC2_DRIVE_POWER ((DRV_CUTBACK_LVL2 / 100.0f) * MAX_DRIVE_POWER) if (soc <= DRV_CUTBACK_SOC2) { float factor = soc / DRV_CUTBACK_SOC2; drvpwr = factor * SOC2_DRIVE_POWER; } else if (soc <= DRV_CUTBACK_SOC1) { float factor = ((soc - DRV_CUTBACK_SOC2) / (DRV_CUTBACK_SOC1 - DRV_CUTBACK_SOC2)); drvpwr = SOC2_DRIVE_POWER + (factor * (MAX_DRIVE_POWER - SOC2_DRIVE_POWER)); } else { drvpwr = MAX_DRIVE_POWER; } // scale down recuperation power & charge current for high SOC: // 0% at FULL → 100% at → 100% at EMPTY if (soc > 99.99) { // stop charge & reduce recuperation at 100% SOC: recpwr = 500; // TODO: should be 0 when driving, but affects D/R change chgcur = 0; } else if (soc >= CHG_CUTBACK_SOC) { // keep min 1000W / 5A below 100% SOC: float factor = ((100 - soc) / (100 - CHG_CUTBACK_SOC)); recpwr = 1000 + (factor * (MAX_RECUP_POWER - 1000)); chgcur = 5 + (factor * (MAX_CHARGE_CURRENT - 5)); } else { recpwr = MAX_RECUP_POWER; chgcur = MAX_CHARGE_CURRENT; } // ------------------------------------------------------------ // bmsTicker: Check cell voltage difference (min - max) // float cmin = min(c1, min(c2, min(c3, c4))); float cmax = max(c1, max(c2, max(c3, c4))); float cdif = cmax - cmin; #if INPUT_CALIBRATION >= 1 Serial.print(F("> cmin = ")); Serial.println(cmin, 2); Serial.print(F("> cmax = ")); Serial.println(cmax, 2); Serial.print(F("> cdif = ")); Serial.println(cdif, 2); #endif if (cdif >= VOLT_DIFF_SHUTDOWN) { // cell difference is critical: emergency shutdown Serial.println(F("!!! VOLT_SHUTDOWN")); bt.println(F("!!! VOLT_SHUTDOWN")); error |= TWIZY_SERV_BATT | TWIZY_SERV_STOP; twizy.enterState(Error); } else if (cdif >= VOLT_DIFF_ERROR) { // cell difference is high: set STOP signal, reduce drive power, stop recuperation & charge: Serial.println(F("!!! VOLT_ERROR")); bt.println(F("!!! VOLT_ERROR")); error |= TWIZY_SERV_BATT | TWIZY_SERV_STOP; drvpwr /= 4; recpwr /= 4; chgcur = 0; } else if (cdif >= VOLT_DIFF_WARN) { // cell difference detected: reduce power & charge levels: Serial.println(F("!!! VOLT_WARN")); bt.println(F("!!! VOLT_WARN")); error |= TWIZY_SERV_BATT; drvpwr /= 2; recpwr /= 2; chgcur = min(chgcur, 5); } // ---------------------------------------------------------------------- // bmsTicker: Read & check battery temperature // float newtemp; // dual read _seems_ to yield better results (LM35D issue?) newtemp = analogRead(PORT_TEMP); newtemp = BASE_TEMP + analogRead(PORT_TEMP) / 1024.0 * SCALE_TEMP; // raw output for calibration: #if INPUT_CALIBRATION >= 1 Serial.print(F("< temp = ")); Serial.println(newtemp, 2); #endif // smooth... temp = (temp * (SMOOTH_TEMP-1) + newtemp) / SMOOTH_TEMP; if (temp > TEMP_SHUTDOWN) { // battery is burning: emergency shutdown Serial.println(F("!!! TEMP_SHUTDOWN")); bt.println(F("!!! TEMP_SHUTDOWN")); error |= TWIZY_SERV_TEMP | TWIZY_SERV_STOP; twizy.enterState(Error); } else if (temp > TEMP_ERROR) { // battery very hot: set STOP signal, stop recuperation, stop charge: Serial.println(F("!!! TEMP_ERROR")); bt.println(F("!!! TEMP_ERROR")); error |= TWIZY_SERV_TEMP | TWIZY_SERV_STOP; drvpwr /= 4; recpwr = 0; chgcur = 0; } else if (temp > TEMP_WARN) { // battery hot, show warning, reduce recuperation, reduce charge current: Serial.println(F("!!! TEMP_WARN")); bt.println(F("!!! TEMP_WARN")); error |= TWIZY_SERV_TEMP; drvpwr /= 2; recpwr /= 2; chgcur = min(chgcur, 5); } // ---------------------------------------------------------------------- // bmsTicker: Estimate current level // if (twizy.state() == Charging) { curr = chgcur; } else { // OPTION: derive current estimation from voltage difference: //curr = ((newsoc - soc) / 100) * SCALE_CURRENT + OFFSET_CURRENT; //curr = constrain(curr, -500.0, 500.0); curr = 0.0; } // ---------------------------------------------------------------------- // bmsTicker: Update Twizy state // #if INPUT_CALIBRATION >= 1 Serial.println(); #endif twizy.setVoltage(vpack, true); twizy.setCurrent(curr); twizy.setTemperature(temp, temp, true); twizy.setSOC(soc); twizy.setPowerLimits(drvpwr, recpwr); twizy.setChargeCurrent(chgcur); twizy.setError(error); // ---------------------------------------------------------------------- // bmsTicker: Output state to serial port // Serial.println(); Serial.print(F("- volt = ")); Serial.println(vpack, 1); Serial.print(F("- ...c1 = ")); Serial.println(c1, 1); Serial.print(F("- ...c2 = ")); Serial.println(c2, 1); Serial.print(F("- ...c3 = ")); Serial.println(c3, 1); Serial.print(F("- ...c4 = ")); Serial.println(c4, 1); Serial.print(F("- temp = ")); Serial.println(temp, 1); Serial.print(F("- curr = ")); Serial.println(curr, 1); Serial.println(); Serial.print(F("- soc% = ")); Serial.println(soc, 1); Serial.print(F("- drvpwr = ")); Serial.println(drvpwr); Serial.print(F("- recpwr = ")); Serial.println(recpwr); Serial.print(F("- chgcur = ")); Serial.println(chgcur); // ---------------------------------------------------------------------- // bmsTicker: Output state to bluetooth port // bt.print(FS(twizyStateName[twizy.state()])); bt.print(F(" -- ")); bt.print(temp, 1); bt.print(F(" °C -- ")); bt.print(soc, 1); bt.print(F(" %SOC -- ")); bt.println(); if (error != TWIZY_OK) { bt.print(F("ERROR: ")); bt.println(error & 0x0fff, HEX); } bt.print(vpack, 1); bt.print(F(" V -- ")); bt.print(curr, 1); bt.print(F(" A -- ")); bt.print(cdif, 1); bt.print(F(" CD")); bt.println(); bt.print(c1, 1); bt.print(F(" C1 -- ")); bt.print(c2, 1); bt.print(F(" C2 -- ")); bt.print(c3, 1); bt.print(F(" C3 -- ")); bt.print(c4, 1); bt.print(F(" C4 -- ")); bt.println(); bt.println(); } // if (twizy.state() != Off) } // bmsTicker() // ----------------------------------------------------- // SETUP // void setup() { Serial.begin(115200); Serial.println(F("Blazej-BMS " BLAZEJ_BMS_VERSION)); bt.begin(BT_BAUD); twizy.begin(); twizy.attachTicker(bmsTicker); twizy.attachEnterState(bmsEnterState); // Init: twizy.setPowerLimits(drvpwr, recpwr); twizy.setChargeCurrent(chgcur); twizy.setSOC(soc); twizy.setTemperature(temp, temp, true); twizy.setVoltage(vpack, true); twizy.setError(error); twizy.setSOH(100); twizy.setCurrent(0.0); #if TWIZY_CAN_SEND == 0 // Dry run: twizy.enterState(Ready); #endif } // ----------------------------------------------------- // MAIN LOOP // void loop() { twizy.looper(); }