CUER
Code to run on the charger board (used to charge the car from the mains).
Diff: charger.cpp
- Revision:
- 7:70cf5bff23f9
- Parent:
- 5:756fae795d37
- Child:
- 8:e5c07b9b8593
--- a/charger.cpp Sun Jul 30 23:01:15 2017 +0000
+++ b/charger.cpp Sun Sep 10 11:10:54 2017 +0000
@@ -7,25 +7,21 @@
using namespace CAN_IDs;
-void car_interruptHandler();
-void car_CANDataSentCallback();
-void charger_interruptHandler();
-void charger_CANDataSentCallback();
+
void init();
-void get_CAN_data();
+
-void calculate_current(float ¤t);
+float calculate_desired_current(float charger_current, float min_cell_voltage);
void check_timeouts();
void update_LEDS();
-bool idAccepted(int id);
+
DigitalOut green_led(p21); //charging LED
DigitalOut yellow_led(p22); //timeout LED
DigitalOut red_led(p23); //error LED
DigitalIn charge_switch(p8); //switch to enable charging
-void calculate_current(float voltage_error, float temp_margin, float *current, float *voltage);
uint8_t charger_status; //status packet given by charger, see Elcon CAN Specification in google drive
bool precharge_status;
@@ -33,9 +29,7 @@
bool charger_failure;
bool charge_finished;
bool bms_error;
-
-
-//float temp_margin = 0; //degrees C, this is the max cell temperature minus max cell temperature limit, need to avoid this hitting 0
+bool charging;
float min_cell_voltage = 3600; //mV
float max_cell_voltage = 3600;//mV
@@ -44,7 +38,7 @@
float charger_voltage; //mV
float desired_current = 0; //mA
-float desired_voltage = MAX_VOLTAGE; //mV
+float desired_voltage = MAX_PACK_VOLTAGE; //mV
float voltage_error = 1000; //mV //This = RISING_BALANCE_THRESHOLD - max_cell_voltage
@@ -52,29 +46,12 @@
timeouts_t timeouts;
-//CAN stuff. Not that there are two sets because there are two separate CAN buses here; one to communicate with the charger, and one to communicate with the rest of the car (importantly the BMS).
-//The reason that there are two separate CAN buses is because the charger uses the extended CAN frame format, with a 29 bit ID, whereas the car uses the default 11 bit ID.
-CAN car_can(CAR_CAN_READ_PIN, CAR_CAN_WRITE_PIN); //Create a CAN object to handle CAN comms
-CANMessage car_buffer[CAN_BUFFER_SIZE]; //CAN receive buffer
-bool car_safe_to_write[CAN_BUFFER_SIZE]; //Semaphore bit indicating that it's safe to write to the software buffer
-bool car_CAN_data_sent = false;
-
-CAN charger_can(CHARGER_CAN_READ_PIN, CHARGER_CAN_WRITE_PIN); //Create a CAN object to handle CAN comms
-CANMessage charger_buffer[CAN_BUFFER_SIZE]; //CAN receive buffer
-bool charger_safe_to_write[CAN_BUFFER_SIZE]; //Semaphore bit indicating that it's safe to write to the software buffer
-bool charger_CAN_data_sent = false;
-
int main() {
init();
while(1) {
-
- //Reset error indicators
- comms_timeout = false;
- charger_failure = false;
- bms_error = false;
-
+
//get the various data from the CAN packets
get_CAN_data();
@@ -83,15 +60,20 @@
charger_control = STOP_CHARGING;
- if (min_cell_voltage > RISING_BALANCE_THRESHOLD || charge_finished) {
+ //if (min_cell_voltage > RISING_BALANCE_THRESHOLD || charge_finished) { //Note: if balancing is implemented, use this version instead
+ if ((max_cell_voltage > CHARGING_FINISHED_THRESHOLD_VOLTAGE && charger_current < CHARGING_FINISHED_THRESHOLD_CURRENT)
+ || charge_finished
+ || max_cell_voltage > MAX_CELL_VOLTAGE) {
charge_finished = true;
+ charging = false;
if (DEBUG) printf("Charge Finished\r\n");
car_can.write(generate_charging_finished_msg());
charger_control = STOP_CHARGING; //set charger control bit to stop charging
}
- else if (precharge_status && charge_switch.read()) {
- calculate_current(desired_current);
- desired_voltage = MAX_VOLTAGE;
+ else if (precharge_status && !bms_error && !comms_timeout && !charger_failure && charge_switch.read()) {
+ charging = true;
+ desired_current = calculate_desired_current(charger_current, min_cell_voltage);
+ desired_voltage = MAX_PACK_VOLTAGE;
charge_finished = false;
charger_control = START_CHARGING; //set charger control bit to start charging
}
@@ -117,140 +99,48 @@
printf("Min cell voltage = %f \r\n", min_cell_voltage);
printf("Max cell voltage = %f \r\n", max_cell_voltage);
printf("Precharge status is %d \r\n", precharge_status);
+ printf("Voltage error is %f \r\n", voltage_error);
+ printf("\r\n");
}
- wait(TIME_STEP);
+ wait_ms(500);
}
}
-void calculate_current(float ¤t){
-
- float Idot;
+float calculate_desired_current(float _charger_current, float _min_cell_voltage){
+ float _desired_current;
+ _desired_current += 500; //gradually ramp up current when charging starts
- static bool balancing = false;
- if (current < 800 && voltage_error < 100 || balancing) {
- balancing = true;
- if (DEBUG) printf("balancing\r\n");
- Idot = voltage_error *KI_BALANCE;
- }
- else {
- Idot = voltage_error*KI_CHARGE;
+ if (_min_cell_voltage < DEEP_DISCHARGE_THRESHOLD_VOLTAGE) {
+ if(_desired_current > DEEP_DISCHARGE_MAX_CURRENT) {
+ _desired_current = DEEP_DISCHARGE_MAX_CURRENT;
+ }
+ }
+
+ else if(_desired_current > MAX_CURRENT) {
+ _desired_current = MAX_CURRENT;
+ }
+ if(_desired_current < 0) {
+ _desired_current = 0;
}
- current += Idot*TIME_STEP/1000.0;
-
- if(current > MAX_CURRENT) {
- current = MAX_CURRENT;
- }
- if(current < 0) {
- current = 0;
- }
- /*
- //Reduce current if temperature is too high
- if (temp_margin > TEMP_RAMP_START) {
- I = 1 - ((temp_margin - TEMP_RAMP_START) / (TEMP_RAMP_FINISH - TEMP_RAMP_START));
- }
- if (temp_margin > TEMP_RAMP_FINISH) {
- I *= 0;
- }
- */
+ return _desired_current;
}
void init()
{
- for(int i=0; i<CAN_BUFFER_SIZE; i++)
- {
- car_buffer[i].id = BLANK_ID;
- //("%d",buffer[i].id);
- car_safe_to_write[i]= true;
-
- charger_buffer[i].id = BLANK_ID;
- //("%d",buffer[i].id);
- charger_safe_to_write[i]= true;
- }
-
- //Initialise CAN stuff, attach CAN interrupt handlers
- car_can.frequency(CAN_BIT_RATE); //set transmission rate to agreed bit rate
- car_can.reset();
- car_can.attach(&car_interruptHandler, CAN::RxIrq); //receive interrupt handler
- car_can.attach(&car_CANDataSentCallback, CAN::TxIrq); //send interrupt handler
-
- charger_can.frequency(CHARGER_CAN_BIT_RATE); //set transmission rate to agreed bit rate
- charger_can.reset();
- charger_can.attach(&charger_interruptHandler, CAN::RxIrq); //receive interrupt handler
- charger_can.attach(&charger_CANDataSentCallback, CAN::TxIrq); //send interrupt handler
-
//Start comms timeout timers
-
timeouts.BMS_timeout.start();
timeouts.charger_timeout.start();
-
precharge_status = false;
-}
-
-void car_CANDataSentCallback(void) {
- car_CAN_data_sent = true;
-}
-
-void charger_CANDataSentCallback(void) {
- charger_CAN_data_sent = true;
-}
-
-void car_interruptHandler()
-{
- CANMessage msg;
- car_can.read(msg);
- //if(DEBUG) printf("id %d incoming \r\n", msg.id);
- if(idAccepted(msg.id)) {
- for(int i=0; i<CAN_BUFFER_SIZE; i++) {
- if((car_buffer[i].id == msg.id || car_buffer[i].id==BLANK_ID) && car_safe_to_write[i]) {
- //("id %d added to buffer \r\n", msg.id);
- car_buffer[i] = msg;
- //return required so that only first blank buffer entry is converted to incoming message ID each time new message ID is encountered
- return;
- }
- }
- }
+ //Reset error indicators
+ comms_timeout = false;
+ charger_failure = false;
+ bms_error = false;
+ charging = false;
}
-void charger_interruptHandler()
-{
- CANMessage msg;
- charger_can.read(msg);
- //if(DEBUG) printf("id %d incoming \r\n", msg.id);
- if(idAccepted(msg.id)) {
- for(int i=0; i<CAN_BUFFER_SIZE; i++) {
- if((charger_buffer[i].id == msg.id || charger_buffer[i].id==BLANK_ID) && charger_safe_to_write[i]) {
- //("id %d added to buffer \r\n", msg.id);
- charger_buffer[i] = msg;
- //return required so that only first blank buffer entry is converted to incoming message ID each time new message ID is encountered
- return;
- }
- }
- }
-}
-
-bool idAccepted(int id)
-{
- switch(id) {
- case BMS_BASE_ID:
- timeouts.BMS_timeout.reset();
- return true;
-
- case BMS_BASE_ID + MAX_MIN_VOLTAGE:
- case BMS_BASE_ID + BATTERY_STATUS_ID:
- case BMS_BASE_ID + BATTERY_PRECHARGE_ID:
- return true;
- case CHARGER_VI_INFO_ID:
- timeouts.charger_timeout.reset();
- return true;
- default:
- return false;
- }
-}
-
-
void check_timeouts() //Check if it's been too long since any of the other devices in the car have communicated
{
@@ -290,90 +180,3 @@
}
-void get_CAN_data() {
-
- //Import the data from the buffer into a non-volatile, more usable format
- CANMessage car_msgArray[CAN_BUFFER_SIZE]; //Same as above but some functions take message as their parameter
- int car_received_CAN_IDs[CAN_BUFFER_SIZE]; //needed to keep track of which IDs we've received so far
- for (int i = 0; i<CAN_BUFFER_SIZE; ++i)
- {
- car_safe_to_write[i] = false;
- car_received_CAN_IDs[i] = car_buffer[i].id;
- car_msgArray[i] = car_buffer[i];
- car_buffer[i].id = BLANK_ID; //this effectively clears the buffer, so that we never reuse old values
- car_safe_to_write[i] = true;
-
- //Now actually import the data from the CAN packets into the global variables
- switch (car_received_CAN_IDs[i]) {
-
- case BMS_BASE_ID:
- break;
-
- case BMS_BASE_ID + MAX_MIN_VOLTAGE:
- get_max_min_voltage(car_msgArray[i], min_cell_voltage, max_cell_voltage);
- voltage_error = RISING_BALANCE_THRESHOLD - max_cell_voltage;
- break;
-
- case BMS_BASE_ID + BATTERY_STATUS_ID:
- get_battery_status(car_msgArray[i], bms_error);
- break;
-
- case BMS_BASE_ID + BATTERY_PRECHARGE_ID:
- check_precharge_status(car_msgArray[i], precharge_status);
- break;
-
- case BLANK_ID: //This means we haven't received this type of message yet, so do nothing
- break;
- default:
- break;
- }
- }
-
- //Import the data from the buffer into a non-volatile, more usable format
- CANMessage charger_msgArray[CAN_BUFFER_SIZE]; //Same as above but some functions take message as their parameter
- int charger_received_CAN_IDs[CAN_BUFFER_SIZE]; //needed to keep track of which IDs we've received so far
- for (int i = 0; i<CAN_BUFFER_SIZE; ++i)
- {
- charger_safe_to_write[i] = false;
- charger_received_CAN_IDs[i] = charger_buffer[i].id;
- charger_msgArray[i] = charger_buffer[i];
- charger_buffer[i].id = BLANK_ID;
- charger_safe_to_write[i] = true;
-
- //Now actually import the data from the CAN packets into the global variables
- switch (charger_received_CAN_IDs[i]) {
-
- case CHARGER_VI_INFO_ID:
- get_charger_VI_info(charger_msgArray[i], charger_voltage, charger_current, charger_status);
- if(charger_status bitand 1 == 1) {
- if (DEBUG) printf("Charger status: Hardware Failure\r\n");
- charger_failure = true;
- }
-
- if(charger_status bitand 2 == 2) {
- if (DEBUG) printf("Charger status: Over Temperature\r\n");
- charger_failure = true;
- }
-
- if(charger_status bitand 4 == 4) {
- if (DEBUG) printf("Charger status: Input Voltage Wrong\r\n");
- charger_failure = true;
- }
-
- if(charger_status bitand 8 == 8) {
- if (DEBUG) printf("Charger status: Reverse Polarity\r\n");
- charger_failure = true;
- }
-
- if(charger_status bitand 16 == 16) {
- if (DEBUG) printf("Charger status: communication timeout\r\n");
- charger_failure = true;
- }
- break;
- case BLANK_ID: //This means we haven't received this type of message yet, so do nothing
- break;
- default:
- break;
- }
- }
-}
\ No newline at end of file