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: %4umA\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: %2u.%01uV\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;
						printf("Battery T: %3u.%01u%cC\r\n", lBatteryTemperature / 10, lBatteryTemperature % 10, '\xB0');
						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);
						}
					}
					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();
			}
		}
	}
}