Fw 226/mppt rewrite yv

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "embedded-pio"]
+	path = embedded-pio
+	url = https://github.com/badgerloop-software/embedded-pio.git

include/IOManagement.h

@@ -0,0 +1,64 @@
+#ifndef __IO_MANAGEMENT_H__
+#define __IO_MANAGEMENT_H__
+
+#include "const.h"
+#include "INA281.h"
+#include "PID_v1.h"
+#include "thermistor.h"
+
+
+// Solar array and battery data
+typedef struct ArrayData {
+    double dutyCycle = 0;
+    float voltage = 0;
+    float current = 0;
+    float curPower = 0;
+    float temp = 0;
+} ArrayData;
+
+extern volatile ArrayData arrayData[NUM_ARRAYS];
+extern volatile float battVolt;
+
+// If boost converter enabled
+extern volatile bool boostEnabled;
+
+// Charging algorithm mode
+enum class ChargeMode : bool {CONST_CURR, MPPT};
+extern volatile ChargeMode chargeMode;
+
+// pack charge percentage
+extern volatile float packSOC;
+
+// pack charge current limit
+extern volatile float packChargeCurrentLimit;
+
+// net pack current (solar panel IN - motor OUT)
+extern volatile float packCurrent;
+
+// output current to battery
+extern volatile float outputCurrent;
+
+// Sets up automatic updating of IO at specified period
+// New input data will automatically be written to arrayData
+void initData(std::chrono::microseconds updatePeriod);
+
+// Resets the duty cycle PID loops
+void resetPID();
+
+// Resets duty cycle PID for specified array
+void resetArrayPID(int array);
+
+// Sets voltage output for all arrays
+// Value will be capped if outside V_MIN or V_MAX specified in const.h
+void setVoltOut(float voltage);
+
+// Sets voltage output for specified array
+void setArrayVoltOut(float voltage, int array);
+
+// Sets clearing of OV fault
+void clearOVFaultReset(uint8_t value);
+
+// Controls discharging of output capacitors thorugh resistor path
+void setCapDischarge(uint8_t value);
+
+#endif // __IO_MANAGEMENT_H__

include/canmanager.h

@@ -0,0 +1,44 @@
+#ifndef __CAN_MANAGER_H__
+#define __CAN_MANAGER_H__
+
+#include "STM32_CAN.h"
+
+#define DEFAULT_CAN_FREQ 250000     // Match Elcon charger
+
+class CANManager {
+    private:
+        STM32_CAN canBus;                  // object to interface with CAN
+
+    public:
+        /* Constructor initializing bus and all manager functions
+         *
+         * canPort: choose from CAN1, CAN2, CAN3 (NOTE: see STM32_CAN library for more details)
+         * pins: choose from DEF, ALT1, ALT2
+         * frequency: Baud rate of can bus
+         */
+        CANManager(CAN_TypeDef* canPort, CAN_PINS pins, int frequency = DEFAULT_CAN_FREQ);
+
+        /* Reads input message and does any logic handling needed
+         * Intended to be implemented by class extension per board
+         */
+        virtual void readHandler(CAN_message_t msg) = 0;
+
+        /* Send a message over CAN
+         *
+         * messageID: CAN ID to use to identify the signal
+         * data: Payload array
+         * length: Size of data in bytes
+         * timeout: in milliseconds
+         */ 
+        bool sendMessage(int messageID, void* data, int length, int timeout = 10);
+
+        /* Processes CAN (read) messages stored in messageQueue for a set duration. 
+         * THIS IS THE FUNCTION TO CALL FOR PROCESSING CAN READ MESSAGES
+         * 
+         * duration: time in milliseconds
+         */
+        void runQueue(int duration);
+};
+
+
+#endif

include/const.h

@@ -0,0 +1,108 @@
+#ifndef CONST_H
+#define CONST_H
+// this header should include all relevant constant values so they can all be easily changed
+
+
+// ------------- IO INPUT CONSTANTS -------------
+#define IO_UPDATE_PERIOD 100
+#define NUM_ARRAYS 3
+
+// Analog input modifiers (derived from circuitry)
+constexpr float V_SCALE = (103.3/3.3)*3.33;
+constexpr float BATT_V_SCALE = 3.325 * 101;
+
+//Input pins to read voltage for each solar array
+#define VOLT_PIN_1 PA_6
+#define VOLT_PIN_2 PA_4
+#define VOLT_PIN_3 PA_1
+
+//Input pins to read current for each solar array
+#define CURR_PIN_1 PA_7
+#define CURR_PIN_2 PA_5
+#define CURR_PIN_3 PA_3
+
+#define INA_SHUNT_R 0.01
+
+// Input pin to get battery voltage
+#define BATTERY_VOLT_PIN PB_0
+
+// Output pins for voltage control of arrays via PWM
+#define PWM_OUT_1 PA_9
+#define PWM_OUT_2 PA_10
+#define PWM_OUT_3 PA_8
+
+// CAN triggered outputs
+#define OV_FAULT_RST_PIN PB_6
+#define DISCHARGE_CAPS_PIN PB_1
+
+// Output voltage limit 
+#define V_MAX 110
+
+// --------------- PID/PWM CONSTANTS -----------------
+// Loop parameters
+#define P_TERM -0.7 //-3.65 // -2.9
+#define I_TERM -0.2 // -0.06 // -0.1
+#define D_TERM 0 //-0.012 // 0
+
+// Input range
+#define PID_IN_MIN 0
+#define PID_IN_MAX 115
+
+// PID output limits (controls PWM duty cycles)
+#define PWM_DUTY_MIN 0
+#define PWM_DUTY_MAX 0.8
+#define PWM_PERIOD_US 13
+
+// ------------- MPPT ALGO CONSTANTS -------------
+// Initial voltage
+#define INIT_VOLT 9
+
+// initial step size for MPPT updates
+#define INIT_VOLT_STEP 0.5
+
+// Maximum voltage the algo loop can target (want safe offset under danger V_MAX)
+#define V_TARGET_MAX 105
+
+//Maximum current the algo loop can target would be the pack charge current limit
+#define I_TARGET_MAX 20
+
+// Frequency of MPPT algo updates
+#define MPPT_UPDATE_PERIOD 10 * IO_UPDATE_PERIOD
+
+// Current threshold to switch to constant current
+#define CONST_CURR_THRESH packChargeCurrentLimit
+
+// Current threshold to switch to MPPT
+#define MPPT_THRESH packChargeCurrentLimit-0.7
+
+#define CONST_CURR_SAFETY_MULT 0.9
+
+// used for variable step size
+#define MAX_VOLT_STEP 4
+#define MIN_VOLT_STEP 0.5
+
+// try moving targetVoltage when PWM is stuck at either limit 
+#define MOVE_VOLTAGE 5
+#define MAX_STUCK_CYCLES 5
+
+// ------------- TESTING/OTHER CONSTANTS -------------
+// Whether to log data and steps in file. Should only be enabled
+// when microcontroller outputting via serial 
+// 1 for human readable mode
+// 2 for logging/csv mode
+// 3 for showing array 0 values only
+#define DEBUG_PRINT 1
+
+// How fast to transmit data over CAN (and debug prints if on)
+#define DATA_SEND_PERIOD 50ms
+
+// CAN Pins
+#define CAN_RX PA_11
+#define CAN_TX PA_12
+
+// Duration undervoltage fault reset asserted on command 
+#define OV_FAULT_RST_PERIOD 250ms
+
+
+
+#endif // CONST_H

include/ina281.h

@@ -0,0 +1,43 @@
+#ifndef _INA281_H_
+#define _INA281_H_
+
+#include <Wire.h>
+
+/*
+    A class which represents an instance of an INA281 Driver for measuring current across a
+    shunt resistor. The analog output pin of the INA gives the voltage across the shunt resistor 
+    multiplied by a scale factor (default 20). Current is calculated from voltage and resistance 
+    using V = IR.
+*/
+class INA281Driver {
+ private:
+    int analogPin;
+    float resistance;
+    float scaleFactor;
+
+ public:
+
+   /*
+        Creates a new INA281 Driver
+
+        Constructor expects 2 arguments:
+        analogPin - name of analog pin the INA is wired to
+        resistance - resistance of the shunt resistor associated with the INA
+
+        Optional argument:
+        scaleFactor - the factor by which to divide the pin reading to get the correct voltage
+    */
+    INA281Driver(int analogPin, float resistance, float scaleFactor = 20);
+
+    /*
+        Retrieves the current current reading
+    */
+    float readCurrent();   
+
+    /*
+        Retrieves the current voltage reading
+    */
+    float readVoltage();
+};
+
+#endif

include/mppt.h

@@ -0,0 +1,12 @@
+#ifndef __MPPT_H__
+#define __MPPT_H__
+
+#include "const.h"
+#include "IOManagement.h"
+#include "Ticker.h"
+
+extern volatile float targetVoltage[NUM_ARRAYS];
+extern volatile float targetVoltage_C[NUM_ARRAYS];
+
+
+#endif // __MPPT_H__

include/thermistor.h

@@ -0,0 +1,59 @@
+#ifndef __THERMISTOR_H__
+#define __THERMISTOR_H__
+
+#include <Wire.h>
+
+/*
+    Thermistor voltage reading is converted to temperature in a two step process
+
+    1. Thermistor voltage must be converted into thermistor resistance.
+    This is done by solving the voltage divider equation (VCC and other resistor R are 
+    fixed by hardware) for the thermistor voltage
+
+    Measured Voltage = VCC * (Thermistor_Resistance) / (Thermistor_Resistance + R)
+
+    2. Thermistor resistance is converted to temperature through a best fit 
+    log curve built using the specific thermistor model's electrical characteristics.
+    This will involve a pair of magic numbers (mult_const and add_const) generated by
+    fitting a curve to a series of (resistance, temperature) points provided by manufacturer
+
+    Temperature = mult_const * log(Thermistor Resistance) + add_const
+*/
+
+typedef struct{
+    float mult_const;
+    float add_const;
+} Thermistor_Constants;
+
+const Thermistor_Constants NCP21XM472J03RA_Constants = {
+    .mult_const = -27.06,
+    .add_const = 253.11
+};
+
+class Thermistor{
+    private:
+    float mult_const;
+    float add_const;
+    float vcc;
+    float R;
+    int thermVoltPin;
+
+    public:
+    /*
+        Constructor expects at least 2 arguments
+        constants: Struct of log translation function constants from structs above
+        therm_pin: Analog pin the thermistor is wired to
+
+        Optional arguments
+        R: Resistance of resistor in series with thermistor
+        vcc: Total voltage across R and thermistor
+    */
+    Thermistor(const Thermistor_Constants constants, int therm_pin, float R = 4700, float vcc = 3.3);
+
+    /*
+        Retrives current thermistor reading
+    */
+    float get_temperature();
+};
+
+#endif

platformio.ini

@@ -12,3 +12,9 @@
 platform = ststm32
 board = nucleo_l432kc
 framework = arduino
+build_flags = -DHAL_CAN_MODULE_ENABLED
+lib_extra_dirs = ./embedded-pio
+lib_deps = 
+	br3ttb/PID@^1.2.1
+	pazi88/STM32_CAN@^1.1.2
+	sstaub/Ticker@^4.4.0