battery.cpp

#include "AP_Periph.h"

#if AP_PERIPH_BATTERY_ENABLED

/*
  battery support
 */

#include <dronecan_msgs.h>

extern const AP_HAL::HAL &hal;

#ifndef AP_PERIPH_BATTERY_MODEL_NAME
#define AP_PERIPH_BATTERY_MODEL_NAME CAN_APP_NODE_NAME
#endif

/*
  update CAN battery monitor
 */
void AP_Periph_FW::can_battery_update(void)
{
    const uint32_t now_ms = AP_HAL::millis();
    if (now_ms - battery.last_can_send_ms < 100) {
        return;
    }
    battery.last_can_send_ms = now_ms;

    const uint8_t battery_instances = battery_lib.num_instances();
    for (uint8_t i=0; i<battery_instances; i++) {
        if (BIT_IS_SET(g.battery_hide_mask, i)) {
            // do not transmit this battery
            continue;
        }
        if (!battery_lib.healthy(i)) {
            continue;
        }

        uavcan_equipment_power_BatteryInfo pkt {};

        // if a battery serial number is assigned, use that as the ID. Else, use the index.
        // batteries should start their serial numbers at numbers above 255 to avoid conflicts with the battery index offset method of populating the serial number
        const int32_t serial_number = battery_lib.get_serial_number(i);
        pkt.battery_id = (serial_number >= 0) ? serial_number : i+1;

        pkt.voltage = battery_lib.voltage(i);

        float current;
        if (battery_lib.current_amps(current, i)) {
            pkt.current = current;
        }
        float temperature;
        if (battery_lib.get_temperature(temperature, i)) {
            // Battery lib reports temperature in Celsius.
            // Convert Celsius to Kelvin for transmission on CAN.
            pkt.temperature = C_TO_KELVIN(temperature);
        }

        // Populate state of health
        pkt.state_of_health_pct = UAVCAN_EQUIPMENT_POWER_BATTERYINFO_STATE_OF_HEALTH_UNKNOWN;
        uint8_t state_of_health_pct = 0;
        if (battery_lib.get_state_of_health_pct(i, state_of_health_pct)) {
            pkt.state_of_health_pct = state_of_health_pct;
        }

        uint8_t percentage = 0;
        if (battery_lib.capacity_remaining_pct(percentage, i)) {
            pkt.state_of_charge_pct = percentage;
        }
        pkt.model_instance_id = i+1;

#if !defined(HAL_PERIPH_BATTERY_SKIP_NAME)
        // example model_name: "org.ardupilot.ap_periph SN 123"
        hal.util->snprintf((char*)pkt.model_name.data, sizeof(pkt.model_name.data), "%s %ld", AP_PERIPH_BATTERY_MODEL_NAME, (long int)serial_number);
        pkt.model_name.len = strnlen((char*)pkt.model_name.data, sizeof(pkt.model_name.data));
#endif //defined(HAL_PERIPH_BATTERY_SKIP_NAME)

        uint8_t buffer[UAVCAN_EQUIPMENT_POWER_BATTERYINFO_MAX_SIZE];
        const uint16_t total_size = uavcan_equipment_power_BatteryInfo_encode(&pkt, buffer, !periph.canfdout());

        canard_broadcast(UAVCAN_EQUIPMENT_POWER_BATTERYINFO_SIGNATURE,
                        UAVCAN_EQUIPMENT_POWER_BATTERYINFO_ID,
                        CANARD_TRANSFER_PRIORITY_LOW,
                        &buffer[0],
                        total_size);

        // Send individual cell information if available
        if (battery_lib.has_cell_voltages(i)) {
            can_battery_send_cells(i);
        }
    }
}

/*
  send individual cell voltages if available
 */
void AP_Periph_FW::can_battery_send_cells(uint8_t instance)
{
    // allocate space for the packet. This is a large
    // packet that won't fit on the stack, so dynamically allocate
    auto* pkt = NEW_NOTHROW ardupilot_equipment_power_BatteryInfoAux;
    uint8_t* buffer = NEW_NOTHROW uint8_t[ARDUPILOT_EQUIPMENT_POWER_BATTERYINFOAUX_MAX_SIZE];
    if (pkt == nullptr || buffer == nullptr) {
        delete pkt;
        delete [] buffer;
        return;
    }

    // fill in timestamp
    pkt->timestamp.usec = AP_HAL::micros();

    // if a battery serial number is assigned, use that as the ID. Else, use the index.
    // batteries should start their serial numbers at numbers above 255 to avoid conflicts with the battery index offset method of populating the serial number
    const int32_t serial_number = battery_lib.get_serial_number(instance);
    pkt->battery_id = (serial_number >= 0) ? serial_number : instance+1;

    // fill in cell voltages
    const auto &cell_voltages = battery_lib.get_cell_voltages(instance);
    for (uint8_t i = 0; i < ARRAY_SIZE(cell_voltages.cells); i++) {
        if (cell_voltages.cells[i] == 0xFFFFU) {
            break;
        }
        pkt->voltage_cell.data[i] = cell_voltages.cells[i]*0.001;
        pkt->voltage_cell.len = i+1;
    }

    // fill in max current
    float current_amps;
    if (battery_lib.current_amps(current_amps, instance)) {
        pkt->max_current = current_amps;
    } else {
        pkt->max_current = nanf("");
    }
    pkt->nominal_voltage = nanf("");

    // encode and send message:
    const uint16_t total_size = ardupilot_equipment_power_BatteryInfoAux_encode(pkt, buffer, !periph.canfdout());

    canard_broadcast(ARDUPILOT_EQUIPMENT_POWER_BATTERYINFOAUX_SIGNATURE,
                     ARDUPILOT_EQUIPMENT_POWER_BATTERYINFOAUX_ID,
                     CANARD_TRANSFER_PRIORITY_LOW,
                     buffer,
                     total_size);

    // Delete temporary buffers
    delete pkt;
    delete [] buffer;
}

#endif // AP_PERIPH_BATTERY_ENABLED