SITL: add DTS6012M rangefinder simulation

Author: FractalEngineer

libraries/AP_HAL_SITL/SITL_State_common.cpp

@@ -27,6 +27,7 @@
 #include <SITL/SIM_RF_Benewake_TF03.h>
 #include <SITL/SIM_RF_Benewake_TFmini.h>
 #include <SITL/SIM_RF_BLping.h>
+#include <SITL/SIM_RF_DTS6012M.h>
 #include <SITL/SIM_RF_GYUS42v2.h>
 #include <SITL/SIM_RF_JRE.h>
 #include <SITL/SIM_RF_Lanbao.h>
@@ -56,6 +57,7 @@ static const struct {
     { "benewake_tf03", SITL::RF_Benewake_TF03::create },
     { "benewake_tfmini", SITL::RF_Benewake_TFmini::create },
     { "blping", SITL::RF_BLping::create },
+    { "dts6012m", SITL::RF_DTS6012M::create },
     { "gyus42v2", SITL::RF_GYUS42v2::create },
     { "jre", SITL::RF_JRE::create },
     { "lanbao", SITL::RF_Lanbao::create },

libraries/SITL/SIM_RF_DTS6012M.cpp

@@ -0,0 +1,67 @@
+/*
+   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/>.
+ */
+/*
+  Simulator for the DTS6012M serial rangefinder
+*/
+
+#include "SIM_RF_DTS6012M.h"
+
+#include <AP_Math/crc.h>
+
+using namespace SITL;
+
+uint32_t RF_DTS6012M::packet_for_alt(float alt_m, uint8_t *buffer, uint8_t buflen)
+{
+    const uint8_t PACKET_LEN = 23;
+
+    if (buflen < PACKET_LEN) {
+        return 0;
+    }
+
+    // clamp to sensor's 20m max range
+    const uint16_t dist_mm = (uint16_t)MIN((uint32_t)(alt_m * 1000), (uint32_t)20000U);
+
+    // 7-byte header
+    buffer[0] = 0xA5;   // frame header
+    buffer[1] = 0x03;   // device ID
+    buffer[2] = 0x20;   // device type
+    buffer[3] = 0x01;   // command echo (start stream)
+    buffer[4] = 0x00;   // reserved
+    buffer[5] = 0x00;   // data length high byte (14 = 0x000E, big-endian)
+    buffer[6] = 0x0E;   // data length low byte
+
+    // 14-byte data payload
+    buffer[7]  = 0xFF;  // secondary target distance low byte (0xFFFF = invalid)
+    buffer[8]  = 0xFF;  // secondary target distance high byte
+    buffer[9]  = 0x00;  // secondary target correction low
+    buffer[10] = 0x00;  // secondary target correction high
+    buffer[11] = 0x00;  // secondary target intensity low
+    buffer[12] = 0x00;  // secondary target intensity high
+    buffer[13] = dist_mm & 0xFF;  // primary target distance low byte (little-endian, mm)
+    buffer[14] = dist_mm >> 8;    // primary target distance high byte
+    buffer[15] = 0x00;  // primary target correction low
+    buffer[16] = 0x00;  // primary target correction high
+    buffer[17] = 0x10;  // primary target intensity low byte (10000 = 0x2710 → 100% quality)
+    buffer[18] = 0x27;  // primary target intensity high byte
+    buffer[19] = 0x00;  // sunlight base low
+    buffer[20] = 0x00;  // sunlight base high
+
+    // CRC-16/MODBUS over bytes 0–20, stored big-endian (high byte first)
+    const uint16_t crc = calc_crc_modbus(buffer, PACKET_LEN - 2);
+    buffer[21] = crc >> 8;    // CRC high byte
+    buffer[22] = crc & 0xFF;  // CRC low byte
+
+    return PACKET_LEN;
+}

libraries/SITL/SIM_RF_DTS6012M.h

@@ -0,0 +1,48 @@
+/*
+   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/>.
+ */
+/*
+  Simulator for the DTS6012M serial rangefinder
+
+./Tools/autotest/sim_vehicle.py --gdb --debug -v ArduCopter -A --serial5=sim:dts6012m --speedup=1
+
+param set SERIAL5_PROTOCOL 9
+param set RNGFND1_TYPE 47
+graph RANGEFINDER.distance
+graph GLOBAL_POSITION_INT.relative_alt/1000-RANGEFINDER.distance
+reboot
+
+arm throttle
+rc 3 1600
+
+*/
+
+#pragma once
+
+#include "SIM_SerialRangeFinder.h"
+
+namespace SITL {
+
+class RF_DTS6012M : public SerialRangeFinder {
+public:
+
+    static SerialRangeFinder *create() { return NEW_NOTHROW RF_DTS6012M(); }
+
+    uint32_t packet_for_alt(float alt_m, uint8_t *buffer, uint8_t buflen) override;
+
+    uint16_t reading_interval_ms() const override { return 100; }  // 10Hz
+
+};
+
+}