fix: driver LGA60

plugins/driver_espe/espe_driver.hpp

@@ -2,6 +2,7 @@
 #pragma once
 #include "lidar_interface.hpp"
 
+#include <chrono>
 #include <cstdint>
 #include <optional>
 #include <string>
@@ -18,6 +19,11 @@ inline constexpr ModelConfig MODEL_ESPE_LGA60 { "ESPE-LGA60", -160.f, 160.f, 0.0
 // ROS driver; NOT verified on real hardware. open() sends the "RAuto" start
 // command; device parameters (spin rate, resolution, filters) are whatever
 // the vendor Windows config tool programmed — this driver does not set them.
+//
+// The device streams each 20°→340° sweep as several packets, so a scan is
+// assembled across packets and only completes when the sweep closes at 340°
+// (see handle_range_frame). Rotation timing is measured host-side: the wire
+// carries no usable clock.
 class EspeDriver : public LidarDriverInterface {
 public:
     // ip: device address; use_udp selects the transport the device is
@@ -52,6 +58,8 @@ private:
     bool fill_buffer(int timeout_ms);   // one recv() into recv_buf_
     bool parse_buffer();                 // consume frames; true when a scan completed
     void handle_range_frame(const uint8_t* frame, uint16_t data_size);
+    void set_resolution(float inc_deg);  // latch the step + (re)size the revolution
+    void begin_revolution();             // blank the buffer for a fresh sweep
     void finish_scan();
 
     ModelConfig  cfg_;
@@ -66,13 +74,19 @@ private:
     // Stream bytes carried across frame boundaries; per-instance.
     std::string recv_buf_;
 
-    // Per-revolution accumulation
+    // Per-revolution accumulation. A revolution is the device's fixed
+    // 20°→340° sweep, so it holds 320°/angle_inc_deg_ points — several
+    // packets' worth. The header's point counters describe one PACKET and say
+    // nothing about the revolution's size.
     std::vector<float> pending_ranges_;
     std::vector<float> pending_intensities_;
-    float    rev_start_deg_ = 0.f;  // device angle of the revolution's first point
-    float    angle_inc_deg_ = 0.f;
-    uint32_t points_total_  = 0;    // measure_size from the header; 0 = no rev open
-    uint16_t pending_time_  = 0;    // header "time" field, unit unverified
+    float    angle_inc_deg_ = 0.f;  // angular step; 0 = not latched yet
+    uint32_t points_total_  = 0;    // points per revolution = 320° / step
+
+    // Rotation period, measured host-side between completed revolutions: the
+    // wire carries no usable clock (see finish_scan()).
+    std::chrono::steady_clock::time_point last_rev_end_{};
+    bool                                  have_last_rev_ = false;
 
     // Latched from the newest "WSimu" area frame, if the device sends any.
     std::optional<uint16_t> espe_error_status_;