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AP_Proximity: new lightware SF40C driver

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New driver using latest streaming interface
Old driver left in place because older devices cannot be updated
This commit is contained in:
Randy Mackay 2019-11-13 17:46:29 +09:00
parent 88460f4406
commit 083be9331a
4 changed files with 651 additions and 2 deletions
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13
libraries/AP_Proximity/AP_Proximity.cpp
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@ -20,6 +20,7 @@
#include "AP_Proximity_TeraRangerTowerEvo.h"
#include "AP_Proximity_RangeFinder.h"
#include "AP_Proximity_MAV.h"
#include "AP_Proximity_LightWareSF40C.h"
#include "AP_Proximity_SITL.h"
#include "AP_Proximity_MorseSITL.h"
#include "AP_Proximity_AirSimSITL.h"
@ -34,7 +35,7 @@ const AP_Param::GroupInfo AP_Proximity::var_info[] = {
// @Param: _TYPE
// @DisplayName: Proximity type
// @Description: What type of proximity sensor is connected
// @Values: 0:None,1:LightWareSF40C,2:MAVLink,3:TeraRangerTower,4:RangeFinder,5:RPLidarA2,6:TeraRangerTowerEvo,10:SITL,11:MorseSITL,12:AirSimSITL
// @Values: 0:None,7:LightwareSF40c,1:LightWareSF40C-legacy,2:MAVLink,3:TeraRangerTower,4:RangeFinder,5:RPLidarA2,6:TeraRangerTowerEvo,10:SITL,11:MorseSITL,12:AirSimSITL
// @RebootRequired: True
// @User: Standard
AP_GROUPINFO("_TYPE", 1, AP_Proximity, _type[0], 0),
@ -154,7 +155,7 @@ const AP_Param::GroupInfo AP_Proximity::var_info[] = {
// @Param: 2_TYPE
// @DisplayName: Second Proximity type
// @Description: What type of proximity sensor is connected
// @Values: 0:None,1:LightWareSF40C,2:MAVLink,3:TeraRangerTower,4:RangeFinder,5:RPLidarA2,6:TeraRangerTowerEvo
// @Values: 0:None,7:LightwareSF40c,1:LightWareSF40C-legacy,2:MAVLink,3:TeraRangerTower,4:RangeFinder,5:RPLidarA2,6:TeraRangerTowerEvo,10:SITL,11:MorseSITL,12:AirSimSITL
// @User: Advanced
// @RebootRequired: True
AP_GROUPINFO("2_TYPE", 16, AP_Proximity, _type[1], 0),
@ -319,6 +320,14 @@ void AP_Proximity::detect_instance(uint8_t instance)
drivers[instance] = new AP_Proximity_RangeFinder(*this, state[instance]);
return;
case Type::SF40C:
if (AP_Proximity_LightWareSF40C::detect()) {
state[instance].instance = instance;
drivers[instance] = new AP_Proximity_LightWareSF40C(*this, state[instance]);
return;
}
break;
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
case Type::SITL:
state[instance].instance = instance;

1
libraries/AP_Proximity/AP_Proximity.h
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@ -46,6 +46,7 @@ public:
RangeFinder = 4,
RPLidarA2 = 5,
TRTOWEREVO = 6,
SF40C = 7,
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
SITL = 10,
MorseSITL = 11,

488
libraries/AP_Proximity/AP_Proximity_LightWareSF40C.cpp Normal file
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@ -0,0 +1,488 @@
/*
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/>.
*/
#include <AP_Common/AP_Common.h>
#include <AP_HAL/AP_HAL.h>
#include <AP_HAL/utility/sparse-endian.h>
#include <AP_SerialManager/AP_SerialManager.h>
#include <AP_Math/crc.h>
#include "AP_Proximity_LightWareSF40C.h"
extern const AP_HAL::HAL& hal;
#define PROXIMITY_SF40C_HEADER 0xAA
#define PROXIMITY_SF40C_DESIRED_OUTPUT_RATE 3
#define PROXIMITY_SF40C_UART_RX_SPACE 1280
/*
The constructor also initialises the proximity sensor. Note that this
constructor is not called until detect() returns true, so we
already know that we should setup the proximity sensor
*/
AP_Proximity_LightWareSF40C::AP_Proximity_LightWareSF40C(AP_Proximity &_frontend,
AP_Proximity::Proximity_State &_state) :
AP_Proximity_Backend(_frontend, _state)
{
const AP_SerialManager &serial_manager = AP::serialmanager();
_uart = serial_manager.find_serial(AP_SerialManager::SerialProtocol_Lidar360, 0);
if (_uart != nullptr) {
// start uart with larger receive buffer
_uart->begin(serial_manager.find_baudrate(AP_SerialManager::SerialProtocol_Lidar360, 0), PROXIMITY_SF40C_UART_RX_SPACE, 0);
}
}
// detect if a Lightware proximity sensor is connected by looking for a configured serial port
bool AP_Proximity_LightWareSF40C::detect()
{
return AP::serialmanager().find_serial(AP_SerialManager::SerialProtocol_Lidar360, 0) != nullptr;
}
// update the state of the sensor
void AP_Proximity_LightWareSF40C::update(void)
{
if (_uart == nullptr) {
return;
}
// initialise sensor if necessary
initialise();
// process incoming messages
process_replies();
// check for timeout and set health status
if ((_last_distance_received_ms == 0) || ((AP_HAL::millis() - _last_distance_received_ms) > PROXIMITY_SF40C_TIMEOUT_MS)) {
set_status(AP_Proximity::Status::NoData);
} else {
set_status(AP_Proximity::Status::Good);
}
}
// initialise sensor
void AP_Proximity_LightWareSF40C::initialise()
{
// initialise sectors
if (!_sector_initialised) {
init_sectors();
}
// exit immediately if we've sent initialisation requests in the last second
uint32_t now_ms = AP_HAL::millis();
if ((now_ms - _last_request_ms) < 1000) {
return;
}
_last_request_ms = now_ms;
// re-fetch motor state
request_motor_state();
// get token from sensor (required for reseting)
if (!got_token()) {
request_token();
return;
}
// if no replies in last 15 seconds reboot sensor
if ((now_ms > 30000) && (now_ms - _last_reply_ms > 15000)) {
restart_sensor();
return;
}
// if motor is starting up give more time to succeed or fail
if ((_sensor_state.motor_state != MotorState::RUNNING_NORMALLY) &&
(_sensor_state.motor_state != MotorState::FAILED_TO_COMMUNICATE)) {
return;
}
// if motor fails, reset sensor and re-try everything
if (_sensor_state.motor_state == MotorState::FAILED_TO_COMMUNICATE) {
restart_sensor();
return;
}
// motor is running correctly (motor_state is RUNNING_NORMALLY) so request start of streaming
if (!_sensor_state.streaming || (_sensor_state.output_rate != PROXIMITY_SF40C_DESIRED_OUTPUT_RATE)) {
request_stream_start();
return;
}
}
// restart sensor and re-init our state
void AP_Proximity_LightWareSF40C::restart_sensor()
{
// return immediately if no token or a restart has been requested within the last 30sec
uint32_t now_ms = AP_HAL::millis();
if ((_last_restart_ms != 0) && ((now_ms - _last_restart_ms) < 30000)) {
return;
}
// restart sensor and re-initialise sensor state
request_reset();
clear_token();
_last_restart_ms = now_ms;
_sensor_state.motor_state = MotorState::UNKNOWN;
_sensor_state.streaming = false;
_sensor_state.output_rate = 0;
}
// initialise sector angles using user defined ignore areas
void AP_Proximity_LightWareSF40C::init_sectors()
{
// use defaults if no ignore areas defined
uint8_t ignore_area_count = get_ignore_area_count();
if (ignore_area_count == 0) {
_sector_initialised = true;
return;
}
uint8_t sector = 0;
for (uint8_t i=0; i<ignore_area_count; i++) {
// get ignore area info
uint16_t ign_area_angle;
uint8_t ign_area_width;
if (get_ignore_area(i, ign_area_angle, ign_area_width)) {
// calculate how many degrees of space we have between this end of this ignore area and the start of the end
int16_t start_angle, end_angle;
get_next_ignore_start_or_end(1, ign_area_angle, start_angle);
get_next_ignore_start_or_end(0, start_angle, end_angle);
int16_t degrees_to_fill = wrap_360(end_angle - start_angle);
// divide up the area into sectors
while ((degrees_to_fill > 0) && (sector < PROXIMITY_SECTORS_MAX)) {
uint16_t sector_size;
if (degrees_to_fill >= 90) {
// set sector to maximum of 45 degrees
sector_size = 45;
} else if (degrees_to_fill > 45) {
// use half the remaining area to optimise size of this sector and the next
sector_size = degrees_to_fill / 2.0f;
} else {
// 45 degrees or less are left so put it all into the next sector
sector_size = degrees_to_fill;
}
// record the sector middle and width
_sector_middle_deg[sector] = wrap_360(start_angle + sector_size / 2.0f);
_sector_width_deg[sector] = sector_size;
// move onto next sector
start_angle += sector_size;
sector++;
degrees_to_fill -= sector_size;
}
}
}
// set num sectors
_num_sectors = sector;
// re-initialise boundary because sector locations have changed
init_boundary();
// record success
_sector_initialised = true;
}
// send message to sensor
void AP_Proximity_LightWareSF40C::send_message(MessageID msgid, bool write, const uint8_t *payload, uint16_t payload_len)
{
if ((_uart == nullptr) || (payload_len > PROXIMITY_SF40C_PAYLOAD_LEN_MAX)) {
return;
}
// check for sufficient space in outgoing buffer
if (_uart->txspace() < payload_len + 6U) {
return;
}
// write header
_uart->write((uint8_t)PROXIMITY_SF40C_HEADER);
uint16_t crc = crc_xmodem_update(0, PROXIMITY_SF40C_HEADER);
// write flags including payload length
const uint16_t flags = ((payload_len+1) << 6) | (write ? 0x01 : 0);
_uart->write(LOWBYTE(flags));
crc = crc_xmodem_update(crc, LOWBYTE(flags));
_uart->write(HIGHBYTE(flags));
crc = crc_xmodem_update(crc, HIGHBYTE(flags));
// msgid
_uart->write((uint8_t)msgid);
crc = crc_xmodem_update(crc, (uint8_t)msgid);
// payload
if ((payload_len > 0) && (payload != nullptr)) {
for (uint16_t i = 0; i < payload_len; i++) {
_uart->write(payload[i]);
crc = crc_xmodem_update(crc, payload[i]);
}
}
// checksum
_uart->write(LOWBYTE(crc));
_uart->write(HIGHBYTE(crc));
}
// request motor state
void AP_Proximity_LightWareSF40C::request_motor_state()
{
send_message(MessageID::MOTOR_STATE, false, (const uint8_t *)nullptr, 0);
}
// request start of streaming of distances
void AP_Proximity_LightWareSF40C::request_stream_start()
{
// request output rate
const uint8_t desired_rate = PROXIMITY_SF40C_DESIRED_OUTPUT_RATE; // 0 = 20010, 1 = 10005, 2 = 6670, 3 = 2001
send_message(MessageID::OUTPUT_RATE, true, &desired_rate, sizeof(desired_rate));
// request streaming to start
const le32_t val = htole32(3);
send_message(MessageID::STREAM, true, (const uint8_t*)&val, sizeof(val));
}
// request token of sensor
void AP_Proximity_LightWareSF40C::request_token()
{
// request token
send_message(MessageID::TOKEN, false, nullptr, 0);
}
// request reset of sensor
void AP_Proximity_LightWareSF40C::request_reset()
{
// send reset request
send_message(MessageID::RESET, true, _sensor_state.token, ARRAY_SIZE(_sensor_state.token));
}
// check for replies from sensor
void AP_Proximity_LightWareSF40C::process_replies()
{
if (_uart == nullptr) {
return;
}
int16_t nbytes = _uart->available();
while (nbytes-- > 0) {
const int16_t r = _uart->read();
if ((r < 0) || (r > 0xFF)) {
continue;
}
parse_byte((uint8_t)r);
}
}
// process one byte received on serial port
// returns true if a message has been successfully parsed
// state is stored in _msg structure
void AP_Proximity_LightWareSF40C::parse_byte(uint8_t b)
{
// check that payload buffer is large enough
static_assert(ARRAY_SIZE(_msg.payload) == PROXIMITY_SF40C_PAYLOAD_LEN_MAX, "AP_Proximity_LightwareSF40C: check _msg.payload array size ");
// process byte depending upon current state
switch (_msg.state) {
case ParseState::HEADER:
if (b == PROXIMITY_SF40C_HEADER) {
_msg.crc_expected = crc_xmodem_update(0, b);
_msg.state = ParseState::FLAGS_L;
}
break;
case ParseState::FLAGS_L:
_msg.flags_low = b;
_msg.crc_expected = crc_xmodem_update(_msg.crc_expected, b);
_msg.state = ParseState::FLAGS_H;
break;
case ParseState::FLAGS_H:
_msg.flags_high = b;
_msg.crc_expected = crc_xmodem_update(_msg.crc_expected, b);
_msg.payload_len = UINT16_VALUE(_msg.flags_high, _msg.flags_low) >> 6;
if ((_msg.payload_len == 0) || (_msg.payload_len > PROXIMITY_SF40C_PAYLOAD_LEN_MAX)) {
// invalid payload length, abandon message
_msg.state = ParseState::HEADER;
} else {
_msg.state = ParseState::MSG_ID;
}
break;
case ParseState::MSG_ID:
_msg.msgid = (MessageID)b;
_msg.crc_expected = crc_xmodem_update(_msg.crc_expected, b);
if (_msg.payload_len > 1) {
_msg.state = ParseState::PAYLOAD;
} else {
_msg.state = ParseState::CRC_L;
}
_msg.payload_recv = 0;
break;
case ParseState::PAYLOAD:
if (_msg.payload_recv < (_msg.payload_len - 1)) {
_msg.payload[_msg.payload_recv] = b;
_msg.payload_recv++;
_msg.crc_expected = crc_xmodem_update(_msg.crc_expected, b);
}
if (_msg.payload_recv >= (_msg.payload_len - 1)) {
_msg.state = ParseState::CRC_L;
}
break;
case ParseState::CRC_L:
_msg.crc_low = b;
_msg.state = ParseState::CRC_H;
break;
case ParseState::CRC_H:
_msg.crc_high = b;
if (_msg.crc_expected == UINT16_VALUE(_msg.crc_high, _msg.crc_low)) {
process_message();
_last_reply_ms = AP_HAL::millis();
}
_msg.state = ParseState::HEADER;
break;
}
}
// process the latest message held in the _msg structure
void AP_Proximity_LightWareSF40C::process_message()
{
// process payload
switch (_msg.msgid) {
case MessageID::TOKEN:
// copy token into _sensor_state.token variable
if (_msg.payload_recv == ARRAY_SIZE(_sensor_state.token)) {
memcpy(_sensor_state.token, _msg.payload, ARRAY_SIZE(_sensor_state.token));
}
break;
case MessageID::RESET:
// no need to do anything
break;
case MessageID::STREAM:
if (_msg.payload_recv == sizeof(uint32_t)) {
_sensor_state.streaming = (buff_to_uint32(_msg.payload[0], _msg.payload[1], _msg.payload[2], _msg.payload[3]) == 3);
}
break;
case MessageID::DISTANCE_OUTPUT: {
_last_distance_received_ms = AP_HAL::millis();
const uint16_t point_total = buff_to_uint16(_msg.payload[8], _msg.payload[9]);
const uint16_t point_count = buff_to_uint16(_msg.payload[10], _msg.payload[11]);
const uint16_t point_start_index = buff_to_uint16(_msg.payload[12], _msg.payload[13]);
// sanity check point_total
if (point_total == 0) {
break;
}
// prepare to push to object database
Location current_loc;
float current_vehicle_bearing;
const bool database_ready = database_prepare_for_push(current_loc, current_vehicle_bearing);
// process each point
const float angle_inc_deg = (1.0f / point_total) * 360.0f;
const float angle_sign = (frontend.get_orientation(state.instance) == 1) ? -1.0f : 1.0f;
const float angle_correction = frontend.get_yaw_correction(state.instance);
const uint16_t dist_min_cm = distance_min() * 100;
const uint16_t dist_max_cm = distance_max() * 100;
for (uint16_t i = 0; i < point_count; i++) {
const uint16_t idx = 14 + (i * 2);
const int16_t dist_cm = (int16_t)buff_to_uint16(_msg.payload[idx], _msg.payload[idx+1]);
const float angle_deg = wrap_360((point_start_index + i) * angle_inc_deg * angle_sign + angle_correction);
uint8_t sector;
if (convert_angle_to_sector(angle_deg, sector)) {
if (sector != _last_sector) {
// update boundary used for avoidance
if (_last_sector != UINT8_MAX) {
update_boundary_for_sector(_last_sector, false);
}
_last_sector = sector;
// init for new sector
_distance[sector] = INT16_MAX;
_distance_valid[sector] = false;
}
if ((dist_cm >= dist_min_cm) && (dist_cm <= dist_max_cm)) {
// use shortest valid distance for this sector's distance
const float dist_m = dist_cm * 0.01f;
if (dist_m < _distance[sector]) {
_angle[sector] = angle_deg;
_distance[sector] = dist_m;
_distance_valid[sector] = true;
}
// send point to object avoidance database
if (database_ready) {
database_push(angle_deg, dist_m, _last_distance_received_ms, current_loc, current_vehicle_bearing);
}
}
}
}
break;
}
case MessageID::MOTOR_STATE:
if (_msg.payload_recv == 1) {
_sensor_state.motor_state = (MotorState)_msg.payload[0];
}
break;
case MessageID::OUTPUT_RATE:
if (_msg.payload_recv == 1) {
_sensor_state.output_rate = _msg.payload[0];
}
break;
// unsupported messages
case MessageID::PRODUCT_NAME:
case MessageID::HARDWARE_VERSION:
case MessageID::FIRMWARE_VERSION:
case MessageID::SERIAL_NUMBER:
case MessageID::TEXT_MESSAGE:
case MessageID::USER_DATA:
case MessageID::SAVE_PARAMETERS:
case MessageID::STAGE_FIRMWARE:
case MessageID::COMMIT_FIRMWARE:
case MessageID::INCOMING_VOLTAGE:
case MessageID::LASER_FIRING:
case MessageID::TEMPERATURE:
case MessageID::BAUD_RATE:
case MessageID::DISTANCE:
case MessageID::MOTOR_VOLTAGE:
case MessageID::FORWARD_OFFSET:
case MessageID::REVOLUTIONS:
case MessageID::ALARM_STATE:
case MessageID::ALARM1:
case MessageID::ALARM2:
case MessageID::ALARM3:
case MessageID::ALARM4:
case MessageID::ALARM5:
case MessageID::ALARM6:
case MessageID::ALARM7:
break;
}
}
// convert buffer to uint32, uint16
uint32_t AP_Proximity_LightWareSF40C::buff_to_uint32(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3) const
{
uint32_t leval = (uint32_t)b0 | (uint32_t)b1 << 8 | (uint32_t)b2 << 16 | (uint32_t)b3 << 24;
return leval;
}
uint16_t AP_Proximity_LightWareSF40C::buff_to_uint16(uint8_t b0, uint8_t b1) const
{
uint16_t leval = (uint16_t)b0 | (uint16_t)b1 << 8;
return leval;
}

151
libraries/AP_Proximity/AP_Proximity_LightWareSF40C.h Normal file
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@ -0,0 +1,151 @@
#pragma once
#include "AP_Proximity.h"
#include "AP_Proximity_Backend.h"
#define PROXIMITY_SF40C_TIMEOUT_MS 200 // requests timeout after 0.2 seconds
#define PROXIMITY_SF40C_PAYLOAD_LEN_MAX 256 // maximum payload size we can accept (in some configurations sensor may send as large as 1023)
class AP_Proximity_LightWareSF40C : public AP_Proximity_Backend
{
public:
// constructor
AP_Proximity_LightWareSF40C(AP_Proximity &_frontend,
AP_Proximity::Proximity_State &_state);
// static detection function
static bool detect();
// update state
void update(void) override;
// get maximum and minimum distances (in meters) of sensor
float distance_max() const override { return 100.0f; }
float distance_min() const override { return 0.20f; }
private:
// initialise sensor
void initialise();
void init_sectors();
// restart sensor and re-init our state
void restart_sensor();
// message ids
enum class MessageID : uint8_t {
PRODUCT_NAME = 0,
HARDWARE_VERSION = 1,
FIRMWARE_VERSION = 2,
SERIAL_NUMBER = 3,
TEXT_MESSAGE = 7,
USER_DATA = 9,
TOKEN = 10,
SAVE_PARAMETERS = 12,
RESET = 14,
STAGE_FIRMWARE = 16,
COMMIT_FIRMWARE = 17,
INCOMING_VOLTAGE = 20,
STREAM = 30,
DISTANCE_OUTPUT = 48,
LASER_FIRING = 50,
TEMPERATURE = 55,
BAUD_RATE = 90,
DISTANCE = 105,
MOTOR_STATE = 106,
MOTOR_VOLTAGE = 107,
OUTPUT_RATE = 108,
FORWARD_OFFSET = 109,
REVOLUTIONS = 110,
ALARM_STATE = 111,
ALARM1 = 112,
ALARM2 = 113,
ALARM3 = 114,
ALARM4 = 115,
ALARM5 = 116,
ALARM6 = 117,
ALARM7 = 118
};
// motor states
enum class MotorState : uint8_t {
UNKNOWN = 0,
PREPARING_FOR_STARTUP = 1,
WAITING_FOR_FIVE_REVS = 2,
RUNNING_NORMALLY = 3,
FAILED_TO_COMMUNICATE = 4
};
// send message to sensor
void send_message(MessageID msgid, bool write, const uint8_t *payload, uint16_t payload_len);
// request motor state
void request_motor_state();
// request start of streaming of distances
void request_stream_start();
// request token of sensor (required for reset)
void request_token();
bool got_token() const { return (_sensor_state.token[0] != 0 || _sensor_state.token[1] != 0); }
void clear_token() { memset(_sensor_state.token, 0, ARRAY_SIZE(_sensor_state.token)); }
// request reset of sensor
void request_reset();
// check and process replies from sensor
void process_replies();
// process one byte received on serial port
// state is stored in msg structure. when a full package is received process_message is called
void parse_byte(uint8_t b);
// process the latest message held in the msg structure
void process_message();
// internal variables
AP_HAL::UARTDriver *_uart; // uart for communicating with sensor
bool _sector_initialised; // true if sectors have been initialised
uint32_t _last_request_ms; // system time of last request
uint32_t _last_reply_ms; // system time of last valid reply
uint32_t _last_restart_ms; // system time we restarted the sensor
uint32_t _last_distance_received_ms; // system time of last distance measurement received from sensor
uint8_t _last_sector = UINT8_MAX; // sector of last distance_cm
// state of sensor
struct {
MotorState motor_state; // motor state (1=starting-up,2=waiting for first 5 revs, 3=normal, 4=comm failure)
uint8_t output_rate; // output rate number (0 = 20010, 1 = 10005, 2 = 6670, 3 = 2001)
bool streaming; // true if distance messages are being streamed
uint8_t token[2]; // token (supplied by sensor) required for reset
} _sensor_state;
enum class ParseState {
HEADER = 0,
FLAGS_L,
FLAGS_H,
MSG_ID,
PAYLOAD,
CRC_L,
CRC_H
};
// structure holding latest message contents
struct {
ParseState state; // state of incoming message processing
uint8_t flags_low; // flags low byte
uint8_t flags_high; // flags high byte
uint16_t payload_len; // latest message payload length (1+ bytes in payload)
uint8_t payload[PROXIMITY_SF40C_PAYLOAD_LEN_MAX]; // payload
MessageID msgid; // latest message's message id
uint16_t payload_recv; // number of message's payload bytes received so far
uint8_t crc_low; // crc low byte
uint8_t crc_high; // crc high byte
uint16_t crc_expected; // latest message's expected crc
} _msg;
// convert buffer to uint32, uint16
uint32_t buff_to_uint32(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3) const;
uint16_t buff_to_uint16(uint8_t b0, uint8_t b1) const;
};