powermgmt.c

#include <stdio.h>
#include "powermgmt.h"
#include "timers.h"

#define xDelay100  ((TickType_t)100 / portTICK_PERIOD_MS)

#define IS_CHARGER_CONNECTED()  (LPC_GPIO1->FIOPIN & (1<<21))
#define IS_CHARGER_ENABLED()    (LPC_GPIO1->FIOPIN & (1<<23))
#define IS_CHARGING()           (IS_CHARGER_CONNECTED() && IS_CHARGER_ENABLED())

#define ENABLE_CHARGER()        do { LPC_GPIO1->FIOSET = (1<<23); } while(0)
#define DISABLE_CHARGER()       do { LPC_GPIO1->FIOCLR = (1<<23); } while(0)

#define BATTERY_MAX_VOLTAGE  287
#define BATTERY_MIN_VOLTAGE  237

xQueueHandle xPowerMgmtMsgQueue;

int32_t lChargeCurrent;
int32_t lBatteryVoltage;
int32_t lBatteryTemperature;

void task_PowerMgmt(void *pvParameters)
{
    xPowerMgmtMsgQueue = xQueueCreate(20, sizeof(xPowerMgmtMsg));
    lChargeCurrent = INT32_MIN;
    lBatteryVoltage = INT32_MIN;
    lBatteryTemperature = INT32_MIN;

    // P1.21 - Charger connected (input, high active)
    // for approx. 2sec after connected to charger (led turns red), it is high
    LPC_PINCON->PINMODE3 &= ~(3 << ((21 - 16) * 2));
    LPC_PINCON->PINMODE3 |= (2 << ((21 - 16) * 2)); // no pullup/-down
    LPC_PINCON->PINSEL3 &= ~(3 << ((21 - 16) * 2)); // plain gpio
    LPC_GPIO1->FIODIR &= ~(1 << 21); // input

    // P1.23 - Enable charger (output, high active)
    LPC_PINCON->PINMODE3 &= ~(3 << ((23 - 16) * 2));
    LPC_PINCON->PINMODE3 |= (2 << ((23 - 16) * 2)); // no pullup/-down
    LPC_PINCON->PINSEL3 &= ~(3 << ((23 - 16) * 2)); // plain gpio
    LPC_GPIO1->FIODIR |= (1 << 23); // output
    DISABLE_CHARGER();

    for (;;) {
        xPowerMgmtMsg msg;
        if (xQueueReceive(xPowerMgmtMsgQueue, &msg, xDelay100) == pdTRUE) {
            switch (msg.xType) {
                case (MEASUREMENT_BATTERY): {
                        /* https://hackaday.io/project/6717-project-landlord/discussion-58892 */
                        if (msg.measurement.lChargeCurrent != INT32_MIN) {
                            lChargeCurrent = msg.measurement.lChargeCurrent;
                            printf("Charge I: %4lumA\r\n", lChargeCurrent);
                        }
                        if (msg.measurement.lBatteryVoltage != INT32_MIN) {
                            // orig fw: v16_batteryLowV = 237; - 23.7V (fixed point) - 3.386V per cell
                            // orig fw: v18_batteryFullCharge = 287; - 28.7V (fixed point) - 4.1V per cell
                            lBatteryVoltage = msg.measurement.lBatteryVoltage;
                            printf("Battery U: %2lu.%01luV\r\n", lBatteryVoltage / 10, lBatteryVoltage % 10);
                            if ((lBatteryVoltage < BATTERY_MIN_VOLTAGE) && !IS_CHARGER_CONNECTED()) { /* below 23.7V - switch off to protect battery! */
                                /* issue shutdown to self */
                                xPowerMgmtMsg msg;
                                msg.xType = COMMAND_SHUTDOWN;
                                msg.shutdown.xDelay = xDelay100;
                                printf("Requesting shutdown to protect battery!\r\n");
                                xQueueSend(xPowerMgmtMsgQueue, &msg, (TickType_t)0);
                            } else if (lBatteryVoltage > BATTERY_MAX_VOLTAGE) { /* over 28.7V - stop charging! */
                            }
                        }
                        if (msg.measurement.lBatteryTemperature != INT32_MIN) {
                            lBatteryTemperature = msg.measurement.lBatteryTemperature;
                            if (lBatteryTemperature > 400) { /* above 40.0°C - switch off to protect battery! */
                                /* issue shutdown to self */
                                xPowerMgmtMsg msg;
                                msg.xType = COMMAND_SHUTDOWN;
                                msg.shutdown.xDelay = xDelay100;
                                printf("Requesting shutdown to protect battery!\r\n");
                                xQueueSend(xPowerMgmtMsgQueue, &msg, (TickType_t)0);
                            }
                            if (lBatteryTemperature >= 0) {
                                printf("Battery T: %3lu.%01lu%cC\r\n", lBatteryTemperature / 10, lBatteryTemperature % 10, '\xB0');
                            } else {
                                lBatteryTemperature = ~lBatteryTemperature;
                                printf("Battery T: -%3lu.%01lu%cC\r\n", lBatteryTemperature / 10, lBatteryTemperature % 10, '\xB0');
                            }

                        }
                        break;
                    }
                case (COMMAND_SHUTDOWN): {
                        printf("Shutting down!\r\n");
                        vTaskDelay(msg.shutdown.xDelay);
                        LPC_GPIO1->FIOPIN &= ~(PIN(25)); // Shutdown
                        __disable_irq(); for (;;);
                    }
                default:
                    printf("Unknown msg\r\n");
            }
        }
        // on each loop (latest every 100ms), check if connected to charger
        if (IS_CHARGER_CONNECTED()) {
            if (!IS_CHARGER_ENABLED()) {
                if ((lBatteryVoltage > (BATTERY_MIN_VOLTAGE - 10)) && (lBatteryVoltage < (BATTERY_MAX_VOLTAGE - 10))) {
                    printf("Start charging\r\n");
                    ENABLE_CHARGER();
                }
            } else {
                if (lBatteryVoltage >= BATTERY_MAX_VOLTAGE) {
                    printf("Stop charging\r\n");
                    DISABLE_CHARGER();
                }
            }
        } else {
            if (IS_CHARGER_ENABLED()) {
                printf("Charger disconnected\r\n");
                DISABLE_CHARGER();
            }
        }
#if LOWSTACKWARNING
        int stack = uxTaskGetStackHighWaterMark(NULL);
        if (stack < 50) printf("Task task_PowerMgmt has %u words left in stack.\r\n", stack);
#endif
    }
}