ardupilot/Tools/AP_Periph/can.cpp

/*
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/*
  AP_Periph can support
 */
#include <AP_HAL/AP_HAL.h>
#include <AP_Math/AP_Math.h>
#include "AP_Periph.h"
#include "hal.h"
#include <canard.h>
#include <uavcan/protocol/dynamic_node_id/Allocation.h>
#include <uavcan/protocol/NodeStatus.h>
#include <uavcan/protocol/RestartNode.h>
#include <uavcan/protocol/GetNodeInfo.h>
#include <uavcan/protocol/file/BeginFirmwareUpdate.h>
#include <uavcan/protocol/param/GetSet.h>
#include <uavcan/protocol/param/ExecuteOpcode.h>
#include <uavcan/equipment/ahrs/MagneticFieldStrength.h>
#include <uavcan/equipment/gnss/Fix.h>
#include <uavcan/equipment/gnss/Auxiliary.h>
#include <uavcan/equipment/air_data/StaticPressure.h>
#include <uavcan/equipment/air_data/StaticTemperature.h>
#include <uavcan/equipment/indication/BeepCommand.h>
#include <uavcan/equipment/indication/LightsCommand.h>
#include <ardupilot/indication/SafetyState.h>
#include <ardupilot/indication/Button.h>
#include <uavcan/protocol/debug/LogMessage.h>
#include <stdio.h>
#include <AP_HAL_ChibiOS/hwdef/common/stm32_util.h>
#include <drivers/stm32/canard_stm32.h>

#include "i2c.h"

extern const AP_HAL::HAL &hal;
extern AP_Periph_FW periph;

static CanardInstance canard;
static uint32_t canard_memory_pool[1024/4];
#ifndef HAL_CAN_DEFAULT_NODE_ID
#define HAL_CAN_DEFAULT_NODE_ID CANARD_BROADCAST_NODE_ID
#endif
static uint8_t PreferredNodeID = HAL_CAN_DEFAULT_NODE_ID;
static uint8_t transfer_id;

#ifndef CAN_APP_VERSION_MAJOR
#define CAN_APP_VERSION_MAJOR                                           1
#endif
#ifndef CAN_APP_VERSION_MINOR
#define CAN_APP_VERSION_MINOR                                           0
#endif
#ifndef CAN_APP_NODE_NAME
#define CAN_APP_NODE_NAME                                               "org.ardupilot.ap_periph"
#endif

/*
 * Variables used for dynamic node ID allocation.
 * RTFM at http://uavcan.org/Specification/6._Application_level_functions/#dynamic-node-id-allocation
 */
static uint32_t send_next_node_id_allocation_request_at_ms; ///< When the next node ID allocation request should be sent
static uint8_t node_id_allocation_unique_id_offset;         ///< Depends on the stage of the next request

/*
 * Node status variables
 */
static uavcan_protocol_NodeStatus node_status;


/**
 * Returns a pseudo random float in the range [0, 1].
 */
static float getRandomFloat(void)
{
    return float(get_random16()) / 0xFFFF;
}


/*
  get cpu unique ID
 */
static void readUniqueID(uint8_t* out_uid)
{
    uint8_t len = UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH;
    memset(out_uid, 0, len);
    hal.util->get_system_id_unformatted(out_uid, len);
}


/*
  handle a GET_NODE_INFO request
 */
static void handle_get_node_info(CanardInstance* ins,
                                 CanardRxTransfer* transfer)
{
    uint8_t buffer[UAVCAN_PROTOCOL_GETNODEINFO_RESPONSE_MAX_SIZE] {};
    uavcan_protocol_GetNodeInfoResponse pkt {};

    node_status.uptime_sec = AP_HAL::millis() / 1000U;

    pkt.status = node_status;
    pkt.software_version.major = CAN_APP_VERSION_MAJOR;
    pkt.software_version.minor = CAN_APP_VERSION_MINOR;

    readUniqueID(pkt.hardware_version.unique_id);

    char name[strlen(CAN_APP_NODE_NAME)+1];
    strcpy(name, CAN_APP_NODE_NAME);
    pkt.name.len = strlen(CAN_APP_NODE_NAME);
    pkt.name.data = (uint8_t *)name;

    uint16_t total_size = uavcan_protocol_GetNodeInfoResponse_encode(&pkt, buffer);

    const int16_t resp_res = canardRequestOrRespond(ins,
                                                    transfer->source_node_id,
                                                    UAVCAN_PROTOCOL_GETNODEINFO_SIGNATURE,
                                                    UAVCAN_PROTOCOL_GETNODEINFO_ID,
                                                    &transfer->transfer_id,
                                                    transfer->priority,
                                                    CanardResponse,
                                                    &buffer[0],
                                                    total_size);
    if (resp_res <= 0) {
        printf("Could not respond to GetNodeInfo: %d\n", resp_res);
    }
}

/*
  handle parameter GetSet request
 */
static void handle_param_getset(CanardInstance* ins, CanardRxTransfer* transfer)
{
    uavcan_protocol_param_GetSetRequest req;
    uint8_t arraybuf[UAVCAN_PROTOCOL_PARAM_GETSET_REQUEST_NAME_MAX_LENGTH];
    uint8_t *arraybuf_ptr = arraybuf;
    if (uavcan_protocol_param_GetSetRequest_decode(transfer, transfer->payload_len, &req, &arraybuf_ptr) < 0) {
        return;
    }

    uavcan_protocol_param_GetSetResponse pkt {};

    uint8_t name[AP_MAX_NAME_SIZE+1] {};
    AP_Param *vp;
    enum ap_var_type ptype;

    if (req.name.len != 0 && req.name.len >= AP_MAX_NAME_SIZE) {
        vp = nullptr;
    } else if (req.name.len != 0 && req.name.len < AP_MAX_NAME_SIZE) {
        strncpy((char *)name, (char *)req.name.data, req.name.len);
        vp = AP_Param::find((char *)name, &ptype);
    } else {
        AP_Param::ParamToken token;
        vp = AP_Param::find_by_index(req.index, &ptype, &token);
        if (vp != nullptr) {
            vp->copy_name_token(token, (char *)name, AP_MAX_NAME_SIZE+1, true);
        }
    }
    if (vp != nullptr && req.name.len != 0 && req.value.union_tag != UAVCAN_PROTOCOL_PARAM_VALUE_EMPTY) {
        // param set
        switch (ptype) {
        case AP_PARAM_INT8:
            if (req.value.union_tag != UAVCAN_PROTOCOL_PARAM_VALUE_INTEGER_VALUE) {
                return;
            }
            ((AP_Int8 *)vp)->set_and_save_ifchanged(req.value.integer_value);
            break;
        case AP_PARAM_INT16:
            if (req.value.union_tag != UAVCAN_PROTOCOL_PARAM_VALUE_INTEGER_VALUE) {
                return;
            }
            ((AP_Int16 *)vp)->set_and_save_ifchanged(req.value.integer_value);
            break;
        case AP_PARAM_INT32:
            if (req.value.union_tag != UAVCAN_PROTOCOL_PARAM_VALUE_INTEGER_VALUE) {
                return;
            }
            ((AP_Int32 *)vp)->set_and_save_ifchanged(req.value.integer_value);
            break;
        case AP_PARAM_FLOAT:
            if (req.value.union_tag != UAVCAN_PROTOCOL_PARAM_VALUE_REAL_VALUE) {
                return;
            }
            ((AP_Float *)vp)->set_and_save_ifchanged(req.value.real_value);
            break;
        default:
            return;
        }
    }
    if (vp != nullptr) {
        switch (ptype) {
        case AP_PARAM_INT8:
            pkt.value.union_tag = UAVCAN_PROTOCOL_PARAM_VALUE_INTEGER_VALUE;
            pkt.value.integer_value = ((AP_Int8 *)vp)->get();
            break;
        case AP_PARAM_INT16:
            pkt.value.union_tag = UAVCAN_PROTOCOL_PARAM_VALUE_INTEGER_VALUE;
            pkt.value.integer_value = ((AP_Int16 *)vp)->get();
            break;
        case AP_PARAM_INT32:
            pkt.value.union_tag = UAVCAN_PROTOCOL_PARAM_VALUE_INTEGER_VALUE;
            pkt.value.integer_value = ((AP_Int32 *)vp)->get();
            break;
        case AP_PARAM_FLOAT:
            pkt.value.union_tag = UAVCAN_PROTOCOL_PARAM_VALUE_REAL_VALUE;
            pkt.value.real_value = ((AP_Float *)vp)->get();
            break;
        default:
            return;
        }
        pkt.name.len = strlen((char *)name);
        pkt.name.data = name;
    }

    uint8_t buffer[UAVCAN_PROTOCOL_PARAM_GETSET_RESPONSE_MAX_SIZE];
    uint16_t total_size = uavcan_protocol_param_GetSetResponse_encode(&pkt, buffer);

    canardRequestOrRespond(ins,
                           transfer->source_node_id,
                           UAVCAN_PROTOCOL_PARAM_GETSET_SIGNATURE,
                           UAVCAN_PROTOCOL_PARAM_GETSET_ID,
                           &transfer->transfer_id,
                           transfer->priority,
                           CanardResponse,
                           &buffer[0],
                           total_size);

}

/*
  handle parameter executeopcode request
 */
static void handle_param_executeopcode(CanardInstance* ins, CanardRxTransfer* transfer)
{
    uavcan_protocol_param_ExecuteOpcodeRequest req;
    if (uavcan_protocol_param_ExecuteOpcodeRequest_decode(transfer, transfer->payload_len, &req, nullptr) < 0) {
        return;
    }
    if (req.opcode == UAVCAN_PROTOCOL_PARAM_EXECUTEOPCODE_REQUEST_OPCODE_ERASE) {
        StorageManager::erase();
        AP_Param::erase_all();
        AP_Param::load_all();
        AP_Param::setup_sketch_defaults();
#ifdef HAL_PERIPH_ENABLE_GPS
        AP_Param::setup_object_defaults(&periph.gps, periph.gps.var_info);
#endif
#ifdef HAL_PERIPH_ENABLE_MAG
        AP_Param::setup_object_defaults(&periph.compass, periph.compass.var_info);
#endif
#ifdef HAL_PERIPH_ENABLE_BARO
        AP_Param::setup_object_defaults(&periph.baro, periph.baro.var_info);
#endif
    }

    uavcan_protocol_param_ExecuteOpcodeResponse pkt {};

    pkt.ok = true;

    uint8_t buffer[UAVCAN_PROTOCOL_PARAM_EXECUTEOPCODE_RESPONSE_MAX_SIZE];
    uint16_t total_size = uavcan_protocol_param_ExecuteOpcodeResponse_encode(&pkt, buffer);

    canardRequestOrRespond(ins,
                           transfer->source_node_id,
                           UAVCAN_PROTOCOL_PARAM_EXECUTEOPCODE_SIGNATURE,
                           UAVCAN_PROTOCOL_PARAM_EXECUTEOPCODE_ID,
                           &transfer->transfer_id,
                           transfer->priority,
                           CanardResponse,
                           &buffer[0],
                           total_size);
}

static void handle_begin_firmware_update(CanardInstance* ins, CanardRxTransfer* transfer)
{
    // instant reboot, with backup register used to give bootloader
    // the node_id we rely on the caller re-sending the firmware
    // update request to the bootloader
    set_fast_reboot((rtc_boot_magic)(RTC_BOOT_CANBL | canardGetLocalNodeID(ins)));
    NVIC_SystemReset();
}

static void handle_allocation_response(CanardInstance* ins, CanardRxTransfer* transfer)
{
    // Rule C - updating the randomized time interval
    send_next_node_id_allocation_request_at_ms =
        AP_HAL::millis() + UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_MIN_REQUEST_PERIOD_MS +
        (uint32_t)(getRandomFloat() * UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_MAX_FOLLOWUP_DELAY_MS);

    if (transfer->source_node_id == CANARD_BROADCAST_NODE_ID)
    {
        printf("Allocation request from another allocatee\n");
        node_id_allocation_unique_id_offset = 0;
        return;
    }

    // Copying the unique ID from the message
    static const uint8_t UniqueIDBitOffset = 8;
    uint8_t received_unique_id[UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH];
    uint8_t received_unique_id_len = 0;
    for (; received_unique_id_len < (transfer->payload_len - (UniqueIDBitOffset / 8U)); received_unique_id_len++) {
        assert(received_unique_id_len < UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH);
        const uint8_t bit_offset = (uint8_t)(UniqueIDBitOffset + received_unique_id_len * 8U);
        (void) canardDecodeScalar(transfer, bit_offset, 8, false, &received_unique_id[received_unique_id_len]);
    }

    // Obtaining the local unique ID
    uint8_t my_unique_id[UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH];
    readUniqueID(my_unique_id);

    // Matching the received UID against the local one
    if (memcmp(received_unique_id, my_unique_id, received_unique_id_len) != 0) {
        printf("Mismatching allocation response\n");
        node_id_allocation_unique_id_offset = 0;
        return;         // No match, return
    }

    if (received_unique_id_len < UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH) {
        // The allocator has confirmed part of unique ID, switching to the next stage and updating the timeout.
        node_id_allocation_unique_id_offset = received_unique_id_len;
        send_next_node_id_allocation_request_at_ms -= UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_MIN_REQUEST_PERIOD_MS;

        printf("Matching allocation response: %d\n", received_unique_id_len);
    } else {
        // Allocation complete - copying the allocated node ID from the message
        uint8_t allocated_node_id = 0;
        (void) canardDecodeScalar(transfer, 0, 7, false, &allocated_node_id);
        assert(allocated_node_id <= 127);

        canardSetLocalNodeID(ins, allocated_node_id);
        printf("Node ID allocated: %d\n", allocated_node_id);
    }
}


/*
  fix value of a float for canard float16 format
 */
static void fix_float16(float &f)
{
    *(uint16_t *)&f = canardConvertNativeFloatToFloat16(f);
}


#ifdef HAL_PERIPH_ENABLE_BUZZER
static uint32_t buzzer_start_ms;
static uint32_t buzzer_len_ms;
/*
  handle BeepCommand
 */
static void handle_beep_command(CanardInstance* ins, CanardRxTransfer* transfer)
{
    uavcan_equipment_indication_BeepCommand req;
    if (uavcan_equipment_indication_BeepCommand_decode(transfer, transfer->payload_len, &req, nullptr) < 0) {
        return;
    }
    static bool initialised;
    if (!initialised) {
        initialised = true;
        hal.rcout->init();
        hal.util->toneAlarm_init();
    }
    fix_float16(req.frequency);
    fix_float16(req.duration);
    buzzer_start_ms = AP_HAL::millis();
    buzzer_len_ms = req.duration*1000;
    float volume = constrain_float(periph.g.buzz_volume/100.0, 0, 1);
    hal.util->toneAlarm_set_buzzer_tone(req.frequency, volume, uint32_t(req.duration*1000));
}

/*
  update buzzer
 */
static void can_buzzer_update(void)
{
    if (buzzer_start_ms != 0) {
        uint32_t now = AP_HAL::millis();
        if (now - buzzer_start_ms > buzzer_len_ms) {
            hal.util->toneAlarm_set_buzzer_tone(0, 0, 0);
            buzzer_start_ms = 0;
        }
    }
}
#endif // HAL_PERIPH_ENABLE_BUZZER

#ifdef HAL_GPIO_PIN_SAFE_LED
static uint8_t safety_state;

/*
  handle SafetyState
 */
static void handle_safety_state(CanardInstance* ins, CanardRxTransfer* transfer)
{
    ardupilot_indication_SafetyState req;
    if (ardupilot_indication_SafetyState_decode(transfer, transfer->payload_len, &req, nullptr) < 0) {
        return;
    }
    safety_state = req.status;
}

#ifdef HAL_PERIPH_NEOPIXEL_COUNT
/*
  handle lightscommand
 */
static void handle_lightscommand(CanardInstance* ins, CanardRxTransfer* transfer)
{
    uavcan_equipment_indication_LightsCommand req;
    uint8_t arraybuf[UAVCAN_EQUIPMENT_INDICATION_LIGHTSCOMMAND_MAX_SIZE];
    uint8_t *arraybuf_ptr = arraybuf;
    if (uavcan_equipment_indication_LightsCommand_decode(transfer, transfer->payload_len, &req, &arraybuf_ptr) < 0) {
        return;
    }
    for (uint8_t i=0; i<req.commands.len; i++) {
        uavcan_equipment_indication_SingleLightCommand &cmd = req.commands.data[i];
        // to get the right color proportions we scale the green so that is uses the
        // same number of bits as red and blue
        uint8_t red = cmd.color.red<<3;
        uint8_t green = (cmd.color.green>>1)<<3;
        uint8_t blue = cmd.color.blue<<3;
        if (periph.g.led_brightness != 100 && periph.g.led_brightness >= 0) {
            float scale = periph.g.led_brightness * 0.01;
            red = constrain_int16(red * scale, 0, 255);
            green = constrain_int16(green * scale, 0, 255);
            blue = constrain_int16(blue * scale, 0, 255);
        }
        hal.rcout->set_neopixel_rgb_data(HAL_PERIPH_NEOPIXEL_CHAN, (1U<<HAL_PERIPH_NEOPIXEL_COUNT)-1,
                                         red, green, blue);
    }
    hal.rcout->neopixel_send();
}
#endif

/*
  update safety LED
 */
static void can_safety_LED_update(void)
{
    static uint32_t last_update_ms;
    switch (safety_state) {
    case ARDUPILOT_INDICATION_SAFETYSTATE_STATUS_SAFETY_OFF:
        palWriteLine(HAL_GPIO_PIN_SAFE_LED, SAFE_LED_ON);
        break;
    case ARDUPILOT_INDICATION_SAFETYSTATE_STATUS_SAFETY_ON: {
        uint32_t now = AP_HAL::millis();
        if (now - last_update_ms > 100) {
            last_update_ms = now;
            static uint8_t led_counter;
            const uint16_t led_pattern = 0x5500;
            led_counter = (led_counter+1) % 16;
            palWriteLine(HAL_GPIO_PIN_SAFE_LED, (led_pattern & (1U << led_counter))?!SAFE_LED_ON:SAFE_LED_ON);
        }
        break;
    }
    default:
        palWriteLine(HAL_GPIO_PIN_SAFE_LED, !SAFE_LED_ON);
        break;
    }
}
#endif // HAL_GPIO_PIN_SAFE_LED


#ifdef HAL_GPIO_PIN_SAFE_BUTTON
/*
  update safety button
 */
static void can_safety_button_update(void)
{
    static uint32_t last_update_ms;
    static uint8_t counter;
    uint32_t now = AP_HAL::millis();
    // send at 10Hz when pressed
    if (!palReadLine(HAL_GPIO_PIN_SAFE_BUTTON)) {
        counter = 0;
        return;
    }
    if (now - last_update_ms < 100) {
        return;
    }
    if (counter < 255) {
        counter++;
    }

    last_update_ms = now;
    ardupilot_indication_Button pkt {};
    pkt.button = ARDUPILOT_INDICATION_BUTTON_BUTTON_SAFETY;
    pkt.press_time = counter;

    uint8_t buffer[ARDUPILOT_INDICATION_BUTTON_MAX_SIZE];
    uint16_t total_size = ardupilot_indication_Button_encode(&pkt, buffer);

    canardBroadcast(&canard,
                    ARDUPILOT_INDICATION_BUTTON_SIGNATURE,
                    ARDUPILOT_INDICATION_BUTTON_ID,
                    &transfer_id,
                    CANARD_TRANSFER_PRIORITY_LOW,
                    &buffer[0],
                    total_size);
}
#endif // HAL_GPIO_PIN_SAFE_BUTTON

/**
 * This callback is invoked by the library when a new message or request or response is received.
 */
static void onTransferReceived(CanardInstance* ins,
                               CanardRxTransfer* transfer)
{
    /*
     * Dynamic node ID allocation protocol.
     * Taking this branch only if we don't have a node ID, ignoring otherwise.
     */
    if (canardGetLocalNodeID(ins) == CANARD_BROADCAST_NODE_ID) {
        if (transfer->transfer_type == CanardTransferTypeBroadcast &&
            transfer->data_type_id == UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_ID) {
            handle_allocation_response(ins, transfer);
        }
        return;
    }

    switch (transfer->data_type_id) {
    case UAVCAN_PROTOCOL_GETNODEINFO_ID:
        handle_get_node_info(ins, transfer);
        break;

    case UAVCAN_PROTOCOL_FILE_BEGINFIRMWAREUPDATE_ID:
        handle_begin_firmware_update(ins, transfer);
        break;

    case UAVCAN_PROTOCOL_RESTARTNODE_ID:
        printf("RestartNode\n");
        hal.scheduler->delay(10);
        NVIC_SystemReset();
        break;

    case UAVCAN_PROTOCOL_PARAM_GETSET_ID:
        handle_param_getset(ins, transfer);
        break;

    case UAVCAN_PROTOCOL_PARAM_EXECUTEOPCODE_ID:
        handle_param_executeopcode(ins, transfer);
        break;

#ifdef HAL_PERIPH_ENABLE_BUZZER
    case UAVCAN_EQUIPMENT_INDICATION_BEEPCOMMAND_ID:
        handle_beep_command(ins, transfer);
        break;
#endif

#ifdef HAL_GPIO_PIN_SAFE_LED
    case ARDUPILOT_INDICATION_SAFETYSTATE_ID:
        handle_safety_state(ins, transfer);
        break;
#endif

#ifdef HAL_PERIPH_NEOPIXEL_COUNT
    case UAVCAN_EQUIPMENT_INDICATION_LIGHTSCOMMAND_ID:
        handle_lightscommand(ins, transfer);
        break;
#endif
    }
}


/**
 * This callback is invoked by the library when it detects beginning of a new transfer on the bus that can be received
 * by the local node.
 * If the callback returns true, the library will receive the transfer.
 * If the callback returns false, the library will ignore the transfer.
 * All transfers that are addressed to other nodes are always ignored.
 */
static bool shouldAcceptTransfer(const CanardInstance* ins,
                                 uint64_t* out_data_type_signature,
                                 uint16_t data_type_id,
                                 CanardTransferType transfer_type,
                                 uint8_t source_node_id)
{
    (void)source_node_id;

    if (canardGetLocalNodeID(ins) == CANARD_BROADCAST_NODE_ID)
    {
        /*
         * If we're in the process of allocation of dynamic node ID, accept only relevant transfers.
         */
        if ((transfer_type == CanardTransferTypeBroadcast) &&
            (data_type_id == UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_ID))
        {
            *out_data_type_signature = UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_SIGNATURE;
            return true;
        }
        return false;
    }

    switch (data_type_id) {
    case UAVCAN_PROTOCOL_GETNODEINFO_ID:
        *out_data_type_signature = UAVCAN_PROTOCOL_GETNODEINFO_SIGNATURE;
        return true;
    case UAVCAN_PROTOCOL_FILE_BEGINFIRMWAREUPDATE_ID:
        *out_data_type_signature = UAVCAN_PROTOCOL_FILE_BEGINFIRMWAREUPDATE_SIGNATURE;
        return true;
    case UAVCAN_PROTOCOL_RESTARTNODE_ID:
        *out_data_type_signature = UAVCAN_PROTOCOL_RESTARTNODE_SIGNATURE;
        return true;
    case UAVCAN_PROTOCOL_PARAM_GETSET_ID:
        *out_data_type_signature = UAVCAN_PROTOCOL_PARAM_GETSET_SIGNATURE;
        return true;
    case UAVCAN_PROTOCOL_PARAM_EXECUTEOPCODE_ID:
        *out_data_type_signature = UAVCAN_PROTOCOL_PARAM_EXECUTEOPCODE_SIGNATURE;
        return true;
#ifdef HAL_PERIPH_ENABLE_BUZZER
    case UAVCAN_EQUIPMENT_INDICATION_BEEPCOMMAND_ID:
        *out_data_type_signature = UAVCAN_EQUIPMENT_INDICATION_BEEPCOMMAND_SIGNATURE;
        return true;
#endif
#ifdef HAL_GPIO_PIN_SAFE_LED
    case ARDUPILOT_INDICATION_SAFETYSTATE_ID:
        *out_data_type_signature = ARDUPILOT_INDICATION_SAFETYSTATE_SIGNATURE;
        return true;
#endif
#ifdef HAL_PERIPH_NEOPIXEL_COUNT
    case UAVCAN_EQUIPMENT_INDICATION_LIGHTSCOMMAND_ID:
        *out_data_type_signature = UAVCAN_EQUIPMENT_INDICATION_LIGHTSCOMMAND_SIGNATURE;
        return true;
#endif
    default:
        break;
    }

    return false;
}

static void processTx(void)
{
    static uint8_t fail_count;
    for (const CanardCANFrame* txf = NULL; (txf = canardPeekTxQueue(&canard)) != NULL;) {
        CANTxFrame txmsg {};
        txmsg.DLC = txf->data_len;
        memcpy(txmsg.data8, txf->data, 8);
        txmsg.EID = txf->id & CANARD_CAN_EXT_ID_MASK;
        txmsg.IDE = 1;
        txmsg.RTR = 0;
        if (canTransmit(&CAND1, CAN_ANY_MAILBOX, &txmsg, TIME_IMMEDIATE) == MSG_OK) {
            canardPopTxQueue(&canard);
            fail_count = 0;
        } else {
            // just exit and try again later. If we fail 8 times in a row
            // then start discarding to prevent the pool filling up
            if (fail_count < 8) {
                fail_count++;
            } else {
                canardPopTxQueue(&canard);
            }
            return;
        }
    }
}

static void processRx(void)
{
    CANRxFrame rxmsg {};
    while (canReceive(&CAND1, CAN_ANY_MAILBOX, &rxmsg, TIME_IMMEDIATE) == MSG_OK) {
        CanardCANFrame rx_frame {};

        //palToggleLine(HAL_GPIO_PIN_LED);

        const uint64_t timestamp = AP_HAL::micros64();
        memcpy(rx_frame.data, rxmsg.data8, 8);
        rx_frame.data_len = rxmsg.DLC;
        if(rxmsg.IDE) {
            rx_frame.id = CANARD_CAN_FRAME_EFF | rxmsg.EID;
        } else {
            rx_frame.id = rxmsg.SID;
        }
        canardHandleRxFrame(&canard, &rx_frame, timestamp);
    }
}

static uint16_t pool_peak_percent(void)
{
    const CanardPoolAllocatorStatistics stats = canardGetPoolAllocatorStatistics(&canard);
    const uint16_t peak_percent = (uint16_t)(100U * stats.peak_usage_blocks / stats.capacity_blocks);
    return peak_percent;
}

/**
 * This function is called at 1 Hz rate from the main loop.
 */
static void process1HzTasks(uint64_t timestamp_usec)
{
    /*
     * Purging transfers that are no longer transmitted. This will occasionally free up some memory.
     */
    canardCleanupStaleTransfers(&canard, timestamp_usec);

    /*
     * Printing the memory usage statistics.
     */
    {
        /*
         * The recommended way to establish the minimal size of the memory pool is to stress-test the application and
         * record the worst case memory usage.
         */
        if (pool_peak_percent() > 70) {
            printf("WARNING: ENLARGE MEMORY POOL\n");
        }
    }

    /*
     * Transmitting the node status message periodically.
     */
    {
        uint8_t buffer[UAVCAN_PROTOCOL_NODESTATUS_MAX_SIZE];
        node_status.uptime_sec = AP_HAL::millis() / 1000U;

        node_status.vendor_specific_status_code = hal.util->available_memory();

        uint32_t len = uavcan_protocol_NodeStatus_encode(&node_status, buffer);

        const int16_t bc_res = canardBroadcast(&canard,
                                               UAVCAN_PROTOCOL_NODESTATUS_SIGNATURE,
                                               UAVCAN_PROTOCOL_NODESTATUS_ID,
                                               &transfer_id,
                                               CANARD_TRANSFER_PRIORITY_LOW,
                                               buffer,
                                               len);
        if (bc_res <= 0) {
            printf("broadcast fail %d\n", bc_res);
        } else {
            //printf("broadcast node status OK\n");
        }
    }

    node_status.mode = UAVCAN_PROTOCOL_NODESTATUS_MODE_OPERATIONAL;
}

/*
  wait for dynamic allocation of node ID
 */
static void can_wait_node_id(void)
{
    uint8_t node_id_allocation_transfer_id = 0;

    while (canardGetLocalNodeID(&canard) == CANARD_BROADCAST_NODE_ID)
    {
        printf("Waiting for dynamic node ID allocation... (pool %u)\n", pool_peak_percent());

        send_next_node_id_allocation_request_at_ms =
            AP_HAL::millis() + UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_MIN_REQUEST_PERIOD_MS +
            (uint32_t)(getRandomFloat() * UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_MAX_FOLLOWUP_DELAY_MS);

        while ((AP_HAL::millis() < send_next_node_id_allocation_request_at_ms) &&
               (canardGetLocalNodeID(&canard) == CANARD_BROADCAST_NODE_ID))
        {
            processTx();
            processRx();
            canardCleanupStaleTransfers(&canard, AP_HAL::micros64());
        }

        if (canardGetLocalNodeID(&canard) != CANARD_BROADCAST_NODE_ID)
        {
            break;
        }

        // Structure of the request is documented in the DSDL definition
        // See http://uavcan.org/Specification/6._Application_level_functions/#dynamic-node-id-allocation
        uint8_t allocation_request[CANARD_CAN_FRAME_MAX_DATA_LEN - 1];
        allocation_request[0] = (uint8_t)(PreferredNodeID << 1U);

        if (node_id_allocation_unique_id_offset == 0)
        {
            allocation_request[0] |= 1;     // First part of unique ID
        }

        uint8_t my_unique_id[UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH];
        readUniqueID(my_unique_id);

        static const uint8_t MaxLenOfUniqueIDInRequest = 6;
        uint8_t uid_size = (uint8_t)(UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH - node_id_allocation_unique_id_offset);
        if (uid_size > MaxLenOfUniqueIDInRequest)
        {
            uid_size = MaxLenOfUniqueIDInRequest;
        }

        // Paranoia time
        assert(node_id_allocation_unique_id_offset < UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH);
        assert(uid_size <= MaxLenOfUniqueIDInRequest);
        assert(uid_size > 0);
        assert((uid_size + node_id_allocation_unique_id_offset) <= UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_UNIQUE_ID_MAX_LENGTH);

        memmove(&allocation_request[1], &my_unique_id[node_id_allocation_unique_id_offset], uid_size);

        // Broadcasting the request
        const int16_t bcast_res = canardBroadcast(&canard,
                                                  UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_SIGNATURE,
                                                  UAVCAN_PROTOCOL_DYNAMIC_NODE_ID_ALLOCATION_ID,
                                                  &node_id_allocation_transfer_id,
                                                  CANARD_TRANSFER_PRIORITY_LOW,
                                                  &allocation_request[0],
                                                  (uint16_t) (uid_size + 1));
        if (bcast_res < 0)
        {
            printf("Could not broadcast ID allocation req; error %d\n", bcast_res);
        }

        // Preparing for timeout; if response is received, this value will be updated from the callback.
        node_id_allocation_unique_id_offset = 0;
    }

    printf("Dynamic node ID allocation complete [%d]\n", canardGetLocalNodeID(&canard));
}

void AP_Periph_FW::can_start()
{
    node_status.health = UAVCAN_PROTOCOL_NODESTATUS_HEALTH_OK;
    node_status.mode = UAVCAN_PROTOCOL_NODESTATUS_MODE_INITIALIZATION;
    node_status.uptime_sec = AP_HAL::millis() / 1000U;

    static CANConfig cancfg = {
        CAN_MCR_ABOM | CAN_MCR_AWUM | CAN_MCR_TXFP,
        0
    };

    // calculate optimal CAN timings given PCLK1 and baudrate
    CanardSTM32CANTimings timings {};
    canardSTM32ComputeCANTimings(STM32_PCLK1, unsigned(g.can_baudrate), &timings);
    cancfg.btr = CAN_BTR_SJW(0) |
        CAN_BTR_TS2(timings.bit_segment_2-1) |
        CAN_BTR_TS1(timings.bit_segment_1-1) |
        CAN_BTR_BRP(timings.bit_rate_prescaler-1);
    
    if (g.can_node >= 0 && g.can_node < 128) {
        PreferredNodeID = g.can_node;
    }

    canStart(&CAND1, &cancfg);

    canardInit(&canard, (uint8_t *)canard_memory_pool, sizeof(canard_memory_pool),
               onTransferReceived, shouldAcceptTransfer, NULL);

    if (PreferredNodeID != CANARD_BROADCAST_NODE_ID) {
        canardSetLocalNodeID(&canard, PreferredNodeID);
    }

    // wait for dynamic node ID allocation
    can_wait_node_id();
}


void AP_Periph_FW::can_update()
{
    static uint32_t last_1Hz_ms;
    uint32_t now = AP_HAL::millis();
    if (now - last_1Hz_ms >= 1000) {
        last_1Hz_ms = now;
        process1HzTasks(AP_HAL::micros64());
    }
    can_mag_update();
    can_gps_update();
    can_baro_update();
#ifdef HAL_PERIPH_ENABLE_BUZZER
    can_buzzer_update();
#endif
#ifdef HAL_GPIO_PIN_SAFE_LED
    can_safety_LED_update();
#endif
#ifdef HAL_GPIO_PIN_SAFE_BUTTON
    can_safety_button_update();
#endif
    processTx();
    processRx();
}

/*
  update CAN magnetometer
 */
void AP_Periph_FW::can_mag_update(void)
{
#ifdef HAL_PERIPH_ENABLE_MAG
    compass.read();
#if 1
    if (compass.get_count() == 0) {
        static uint32_t last_probe_ms;
        uint32_t now = AP_HAL::millis();
        if (now - last_probe_ms >= 1000) {
            last_probe_ms = now;
            compass.init();
        }
    }
#endif

    if (last_mag_update_ms == compass.last_update_ms()) {
        return;
    }

    last_mag_update_ms = compass.last_update_ms();
    const Vector3f &field = compass.get_field();
    uavcan_equipment_ahrs_MagneticFieldStrength pkt {};

    // the canard dsdl compiler doesn't understand float16
    for (uint8_t i=0; i<3; i++) {
        pkt.magnetic_field_ga[i] = field[i] * 0.001;
        fix_float16(pkt.magnetic_field_ga[i]);
    }

    uint8_t buffer[UAVCAN_EQUIPMENT_AHRS_MAGNETICFIELDSTRENGTH_MAX_SIZE];
    uint16_t total_size = uavcan_equipment_ahrs_MagneticFieldStrength_encode(&pkt, buffer);

    canardBroadcast(&canard,
                    UAVCAN_EQUIPMENT_AHRS_MAGNETICFIELDSTRENGTH_SIGNATURE,
                    UAVCAN_EQUIPMENT_AHRS_MAGNETICFIELDSTRENGTH_ID,
                    &transfer_id,
                    CANARD_TRANSFER_PRIORITY_LOW,
                    &buffer[0],
                    total_size);
#endif // HAL_PERIPH_ENABLE_MAG
}

/*
  update CAN GPS
 */
void AP_Periph_FW::can_gps_update(void)
{
#ifdef HAL_PERIPH_ENABLE_GPS
    gps.update();
    if (last_gps_update_ms == gps.last_message_time_ms()) {
        return;
    }
    last_gps_update_ms = gps.last_message_time_ms();

    /*
      send Fix packet
     */
    uavcan_equipment_gnss_Fix pkt {};
    const Location &loc = gps.location();
    const Vector3f &vel = gps.velocity();

    pkt.timestamp.usec = AP_HAL::micros64();
    pkt.gnss_timestamp.usec = gps.time_epoch_usec();
    pkt.gnss_time_standard = UAVCAN_EQUIPMENT_GNSS_FIX_GNSS_TIME_STANDARD_UTC;
    pkt.longitude_deg_1e8 = uint64_t(loc.lng) * 10ULL;
    pkt.latitude_deg_1e8 = uint64_t(loc.lat) * 10ULL;
    pkt.height_ellipsoid_mm = loc.alt * 10;
    pkt.height_msl_mm = loc.alt * 10;
    for (uint8_t i=0; i<3; i++) {
        // the canard dsdl compiler doesn't understand float16
        pkt.ned_velocity[i] = vel[i];
        fix_float16(pkt.ned_velocity[i]);
    }
    pkt.sats_used = gps.num_sats();
    switch (gps.status()) {
    case AP_GPS::GPS_Status::NO_GPS:
    case AP_GPS::GPS_Status::NO_FIX:
        pkt.status = UAVCAN_EQUIPMENT_GNSS_FIX_STATUS_NO_FIX;
        break;
    case AP_GPS::GPS_Status::GPS_OK_FIX_2D:
        pkt.status = UAVCAN_EQUIPMENT_GNSS_FIX_STATUS_2D_FIX;
        break;
    case AP_GPS::GPS_Status::GPS_OK_FIX_3D:
    case AP_GPS::GPS_Status::GPS_OK_FIX_3D_DGPS:
    case AP_GPS::GPS_Status::GPS_OK_FIX_3D_RTK_FLOAT:
    case AP_GPS::GPS_Status::GPS_OK_FIX_3D_RTK_FIXED:
        pkt.status = UAVCAN_EQUIPMENT_GNSS_FIX_STATUS_3D_FIX;
        break;
    }

    float pos_cov[9] {};
    pkt.position_covariance.data = &pos_cov[0];
    pkt.position_covariance.len = 9;

    float vacc;
    if (gps.vertical_accuracy(vacc)) {
        pos_cov[8] = sq(vacc);
        fix_float16(pos_cov[8]);
    }

    float hacc;
    if (gps.horizontal_accuracy(hacc)) {
        pos_cov[0] = pos_cov[4] = sq(hacc);
        fix_float16(pos_cov[0]);
        fix_float16(pos_cov[4]);
    }
    
    float vel_cov[9] {};
    pkt.velocity_covariance.data = &pos_cov[0];
    pkt.velocity_covariance.len = 9;

    float sacc;
    if (gps.speed_accuracy(sacc)) {
        float vc3 = sq(sacc/3.0);
        vel_cov[0] = vel_cov[4] = vel_cov[8] = vc3;
        fix_float16(vel_cov[0]);
        fix_float16(vel_cov[4]);
        fix_float16(vel_cov[8]);
    }

    {
        uint8_t buffer[UAVCAN_EQUIPMENT_GNSS_FIX_MAX_SIZE];
        uint16_t total_size = uavcan_equipment_gnss_Fix_encode(&pkt, buffer);

        canardBroadcast(&canard,
                        UAVCAN_EQUIPMENT_GNSS_FIX_SIGNATURE,
                        UAVCAN_EQUIPMENT_GNSS_FIX_ID,
                        &transfer_id,
                        CANARD_TRANSFER_PRIORITY_LOW,
                        &buffer[0],
                        total_size);
    }

    /*
      send aux packet
     */
    {
        uavcan_equipment_gnss_Auxiliary aux {};
        aux.hdop = gps.get_hdop() * 0.01;
        aux.vdop = gps.get_vdop() * 0.01;
        fix_float16(aux.hdop);
        fix_float16(aux.vdop);

        uint8_t buffer[UAVCAN_EQUIPMENT_GNSS_AUXILIARY_MAX_SIZE];
        uint16_t total_size = uavcan_equipment_gnss_Auxiliary_encode(&aux, buffer);
        canardBroadcast(&canard,
                        UAVCAN_EQUIPMENT_GNSS_AUXILIARY_SIGNATURE,
                        UAVCAN_EQUIPMENT_GNSS_AUXILIARY_ID,
                        &transfer_id,
                        CANARD_TRANSFER_PRIORITY_LOW,
                        &buffer[0],
                        total_size);
    }
#endif // HAL_PERIPH_ENABLE_GPS
}

/*
  update CAN baro
 */
void AP_Periph_FW::can_baro_update(void)
{
#ifdef HAL_PERIPH_ENABLE_BARO
    baro.update();
    if (last_baro_update_ms == baro.get_last_update()) {
        return;
    }

    last_baro_update_ms = baro.get_last_update();
    if (!baro.healthy()) {
        // don't send any data
        return;
    }
    const float press = baro.get_pressure();
    const float temp = baro.get_temperature();

    {
        uavcan_equipment_air_data_StaticPressure pkt {};
        pkt.static_pressure = press;
        pkt.static_pressure_variance = 0; // should we make this a parameter?
        fix_float16(pkt.static_pressure_variance);

        uint8_t buffer[UAVCAN_EQUIPMENT_AIR_DATA_STATICPRESSURE_MAX_SIZE];
        uint16_t total_size = uavcan_equipment_air_data_StaticPressure_encode(&pkt, buffer);

        canardBroadcast(&canard,
                        UAVCAN_EQUIPMENT_AIR_DATA_STATICPRESSURE_SIGNATURE,
                        UAVCAN_EQUIPMENT_AIR_DATA_STATICPRESSURE_ID,
                        &transfer_id,
                        CANARD_TRANSFER_PRIORITY_LOW,
                        &buffer[0],
                        total_size);
    }

    {
        uavcan_equipment_air_data_StaticTemperature pkt {};
        pkt.static_temperature = temp + C_TO_KELVIN;
        pkt.static_temperature_variance = 0; // should we make this a parameter?

        fix_float16(pkt.static_temperature);
        fix_float16(pkt.static_temperature_variance);

        uint8_t buffer[UAVCAN_EQUIPMENT_AIR_DATA_STATICTEMPERATURE_MAX_SIZE];
        uint16_t total_size = uavcan_equipment_air_data_StaticTemperature_encode(&pkt, buffer);

        canardBroadcast(&canard,
                        UAVCAN_EQUIPMENT_AIR_DATA_STATICTEMPERATURE_SIGNATURE,
                        UAVCAN_EQUIPMENT_AIR_DATA_STATICTEMPERATURE_ID,
                        &transfer_id,
                        CANARD_TRANSFER_PRIORITY_LOW,
                        &buffer[0],
                        total_size);
    }
#endif // HAL_PERIPH_ENABLE_BARO
}

// printf to CAN LogMessage for debugging
void can_printf(const char *fmt, ...)
{
    uavcan_protocol_debug_LogMessage pkt {};
    uint8_t buffer[UAVCAN_PROTOCOL_DEBUG_LOGMESSAGE_MAX_SIZE];
    char tbuf[100];
    va_list ap;
    va_start(ap, fmt);
    uint32_t n = vsnprintf(tbuf, sizeof(tbuf), fmt, ap);
    va_end(ap);
    pkt.text.len = MIN(n, sizeof(tbuf));
    pkt.text.data = (uint8_t *)&tbuf[0];

    uint32_t len = uavcan_protocol_debug_LogMessage_encode(&pkt, buffer);

    canardBroadcast(&canard,
                    UAVCAN_PROTOCOL_DEBUG_LOGMESSAGE_SIGNATURE,
                    UAVCAN_PROTOCOL_DEBUG_LOGMESSAGE_ID,
                    &transfer_id,
                    CANARD_TRANSFER_PRIORITY_LOW,
                    buffer,
                    len);

}