/* 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 . */ #include #include "AP_RangeFinder_uLanding.h" #include #include extern const AP_HAL::HAL& hal; /* The constructor also initialises the rangefinder. Note that this constructor is not called until detect() returns true, so we already know that we should setup the rangefinder */ AP_RangeFinder_uLanding::AP_RangeFinder_uLanding(RangeFinder &_ranger, uint8_t instance, RangeFinder::RangeFinder_State &_state, AP_SerialManager &serial_manager) : AP_RangeFinder_Backend(_ranger, instance, _state) { uart = serial_manager.find_serial(AP_SerialManager::SerialProtocol_Aerotenna_uLanding, 0); if (uart != nullptr) { uart->begin(serial_manager.find_baudrate(AP_SerialManager::SerialProtocol_Aerotenna_uLanding, 0)); } } /* detect if a uLanding rangefinder is connected. We'll detect by trying to take a reading on Serial. If we get a result the sensor is there. */ bool AP_RangeFinder_uLanding::detect(RangeFinder &_ranger, uint8_t instance, AP_SerialManager &serial_manager) { return serial_manager.find_serial(AP_SerialManager::SerialProtocol_Aerotenna_uLanding, 0) != nullptr; } // read - return last value measured by sensor bool AP_RangeFinder_uLanding::get_reading(uint16_t &reading_cm) { if (uart == nullptr) { return false; } // read any available lines from the uLanding float sum = 0; uint16_t count = 0; uint8_t index = 0; int16_t nbytes = uart->available(); while (nbytes-- > 0) { uint8_t c = uart->read(); // ok, we have located start byte if (c == 72 && index == 0) { linebuf_len = 0; index = 1; } // now it is ready to decode index information if (index == 1) { linebuf[linebuf_len] = c; linebuf_len ++; if (linebuf_len == 3) { index = 0; sum += (linebuf[2]&0x7F) *128 + (linebuf[1]&0x7F); linebuf_len = 0; count ++; } } } if (count == 0) { return false; } reading_cm = 2.5f * sum / count; return true; } /* update the state of the sensor */ void AP_RangeFinder_uLanding::update(void) { if (get_reading(state.distance_cm)) { // update range_valid state based on distance measured last_reading_ms = AP_HAL::millis(); update_status(); } else if (AP_HAL::millis() - last_reading_ms > 200) { set_status(RangeFinder::RangeFinder_NoData); } }