fix: avoid DTR/RTS pulse on serial port open

Previously SetCommState was called with fDtrControl and
fRtsControl left at whatever GetCommState returned (often
enabled), then EscapeCommFunction lowered DTR/RTS after the
fact. This produced a brief low-high-low pulse on connect,
which can reset USB-UART-connected devices.

Set DTR_CONTROL_DISABLE and RTS_CONTROL_DISABLE directly in
the DCB before the single SetCommState call, so the lines
never get pulsed.

celrs/crsf.c

@@ -63,7 +63,7 @@ size_t cel_crsf_build_rc_frame(uint8_t* dst, int16_t const channels[16]) {
     uint8_t length = 1 + 22 + 1; /* type + payload + crc */
     dst[0] = 0xC8; /* RC frame address */
     dst[1] = length;
-    dst[2] = CEL_CRSF_TYPE_RC_CHANNELS_PACKED;
+    dst[2] = CEL_CRSF_TYPE_RC_CHANNELS;
     memcpy(dst + 3, packed, 22);
     uint8_t crc = cel_crsf_crc(dst + 2, 1 + 22);
     dst[2 + length - 1] = crc;

celrs/crsf.h

@@ -18,7 +18,6 @@
 
 /* CRSF frame types (ELRS) */
 typedef enum {
-    CEL_CRSF_TYPE_RC_CHANNELS_PACKED       = 0x01,
     CEL_CRSF_TYPE_GPS                      = 0x02,
     CEL_CRSF_TYPE_VARIO                    = 0x07,
     CEL_CRSF_TYPE_BATTERY                  = 0x08,

celrs/crsf_telemetry.c

@@ -2,10 +2,20 @@
 #include <string.h>
 
 /* Helper: read uint16_t little-endian from buffer */
-static uint16_t read_u16(uint8_t const* buf) {
+static uint16_t read_u16_le(uint8_t const* buf) {
     return (uint16_t)buf[0] | ((uint16_t)buf[1] << 8);
 }
 
+/* Helper: read uint16_t big-endian from buffer */
+static uint16_t read_u16_be(uint8_t const* buf) {
+    return ((uint16_t)buf[0] << 8) | (uint16_t)buf[1];
+}
+
+/* Helper: read uint32_t big-endian from 3-byte buffer */
+static uint32_t read_u24_be(uint8_t const* buf) {
+    return ((uint32_t)buf[0] << 16) | ((uint32_t)buf[1] << 8) | (uint32_t)buf[2];
+}
+
 int cel_crsf_telemetry_parse(cel_crsf_frame const* frame,
                               cel_telemetry* out) {
     if (frame == NULL || out == NULL) return -1;
@@ -32,26 +42,28 @@ int cel_crsf_telemetry_parse(cel_crsf_frame const* frame,
         }
 
         case CEL_CRSF_TYPE_BATTERY: {
-            if (len < 7) return -1;
+            if (len < 8) return -1;
             out->type = CEL_TELEM_BATTERY;
-            out->data.battery.voltage_mv    = read_u16(p);
-            out->data.battery.current_ma    = read_u16(p + 2);
-            out->data.battery.capacity_mah  = read_u16(p + 4);
-            out->data.battery.remaining_pct = p[6];
+            /* CRSF battery: voltage(u16 BE 0.1V), current(u16 BE 0.1A),
+               capacity(u24 BE mAh), remaining(u8 %) */
+            out->data.battery.voltage_x10   = read_u16_be(p);
+            out->data.battery.current_x10   = read_u16_be(p + 2);
+            out->data.battery.capacity_mah  = read_u24_be(p + 4);
+            out->data.battery.remaining_pct = p[7];
             return 0;
         }
 
         case CEL_CRSF_TYPE_HEARTBEAT: {
             if (len < 2) return -1;
             out->type = CEL_TELEM_HEARTBEAT;
-            out->data.heartbeat.origin_addr = read_u16(p);
+            out->data.heartbeat.origin_addr = read_u16_le(p);
             return 0;
         }
 
         case CEL_CRSF_TYPE_AIRSPEED: {
             if (len < 2) return -1;
             out->type = CEL_TELEM_AIRSPEED;
-            out->data.airspeed.speed_kmh = read_u16(p);
+            out->data.airspeed.speed_kmh = read_u16_le(p);
             return 0;
         }
 

celrs/crsf_telemetry.h

@@ -36,11 +36,11 @@ typedef struct {
     int16_t vertical_speed_cms;
 } cel_telem_vario;
 
-/* Battery sensor */
+/* Battery sensor (CRSF: u16 BE 0.1V, u16 BE 0.1A, u24 BE mAh, u8 %) */
 typedef struct {
-    uint16_t voltage_mv;     /* millivolts */
-    uint16_t current_ma;     /* milliamps */
-    uint16_t capacity_mah;   /* mAh consumed */
+    uint16_t voltage_x10;    /* x 0.1V */
+    uint16_t current_x10;    /* x 0.1A */
+    uint32_t capacity_mah;   /* mAh consumed */
     uint8_t  remaining_pct;  /* percentage remaining */
 } cel_telem_battery;
 

celrs/platform/serial_win.c

@@ -27,6 +27,13 @@ cel_serial_platform_handle cel_serial_platform_open(char const* path, int baud_r
     dcb.Parity   = NOPARITY;
     dcb.StopBits = ONESTOPBIT;
 
+    /* Keep DTR/RTS low so the TX module is not reset on connect. Setting
+     * these in the same SetCommState call (rather than via a later
+     * EscapeCommFunction) avoids a brief DTR/RTS-high pulse if the port's
+     * existing DCB has them enabled. */
+    dcb.fDtrControl = DTR_CONTROL_DISABLE;
+    dcb.fRtsControl = RTS_CONTROL_DISABLE;
+
     if (!SetCommState(h, &dcb)) {
         CloseHandle(h);
         return CEL_SERIAL_PLATFORM_INVALID_HANDLE;

tests/test_crsf.c

@@ -193,7 +193,7 @@ void test_build_rc_frame_roundtrip(void) {
 
     cel_crsf_frame frame;
     TEST_ASSERT_EQUAL_INT(0, cel_crsf_frame_parse(&frame, dst, len));
-    TEST_ASSERT_EQUAL_UINT8(CEL_CRSF_TYPE_RC_CHANNELS_PACKED, frame.type);
+    TEST_ASSERT_EQUAL_UINT8(CEL_CRSF_TYPE_RC_CHANNELS, frame.type);
 }
 
 void test_build_ping_frame_null_dst(void) {

tests/test_crsf_telemetry.c

@@ -60,13 +60,15 @@ void test_parse_link_stats_short(void) {
 
 void test_parse_battery(void) {
     uint8_t buf[32];
-    uint8_t payload[7] = {
-        0x40, 0x03, /* voltage: 0x0340 = 832 -> 0.832V */
-        0x00, 0x00, /* current: 0 */
-        0x00, 0x00, /* capacity: 0 */
+    /* CRSF battery: voltage(u16 BE 0.1V), current(u16 BE 0.1A),
+       capacity(u24 BE mAh), remaining(u8 %) = 8 bytes */
+    uint8_t payload[8] = {
+        0x03, 0xE8, /* voltage: 0x03E8 = 1000 -> 100.0V (10S LiPo) */
+        0x00, 0x64, /* current: 0x0064 = 100 -> 10.0A */
+        0x00, 0x03, 0xE8, /* capacity: 0x0003E8 = 1000mAh */
         0x64         /* remaining: 100% */
     };
-    build_frame(buf, 0x08, CEL_CRSF_TYPE_BATTERY, payload, 7);
+    build_frame(buf, 0x08, CEL_CRSF_TYPE_BATTERY, payload, 8);
 
     cel_crsf_frame frame;
     TEST_ASSERT_EQUAL_INT(0, cel_crsf_frame_parse(&frame, buf, sizeof(buf)));
@@ -74,13 +76,15 @@ void test_parse_battery(void) {
     cel_telemetry telem;
     TEST_ASSERT_EQUAL_INT(0, cel_crsf_telemetry_parse(&frame, &telem));
     TEST_ASSERT_EQUAL_UINT(CEL_TELEM_BATTERY, telem.type);
-    TEST_ASSERT_EQUAL_UINT16(0x0340, telem.data.battery.voltage_mv);
+    TEST_ASSERT_EQUAL_UINT16(0x03E8, telem.data.battery.voltage_x10);
+    TEST_ASSERT_EQUAL_UINT16(0x0064, telem.data.battery.current_x10);
+    TEST_ASSERT_EQUAL_UINT32(0x0003E8, telem.data.battery.capacity_mah);
     TEST_ASSERT_EQUAL_UINT8(0x64, telem.data.battery.remaining_pct);
 }
 
 void test_parse_heartbeat(void) {
     uint8_t buf[32];
-    uint8_t payload[2] = {0x10, 0x80}; /* origin_addr = 0x8010 */
+    uint8_t payload[2] = {0x10, 0x80}; /* origin_addr LE = 0x8010 */
     build_frame(buf, 0x10, CEL_CRSF_TYPE_HEARTBEAT, payload, 2);
 
     cel_crsf_frame frame;
@@ -94,7 +98,7 @@ void test_parse_heartbeat(void) {
 
 void test_parse_airspeed(void) {
     uint8_t buf[32];
-    uint8_t payload[2] = {0x00, 0x01}; /* speed = 0x0100 = 256 km/h */
+    uint8_t payload[2] = {0x00, 0x01}; /* speed LE = 0x0100 = 256 km/h */
     build_frame(buf, 0x08, CEL_CRSF_TYPE_AIRSPEED, payload, 2);
 
     cel_crsf_frame frame;

tools/telemetry.c

@@ -79,7 +79,7 @@ static void ansi_cursor_up(int n) {
 /* --------------------------------------------------------------------------- */
 
 #define LINK_STALE_S 3.0f
-#define FC_STALE_S 2.0f
+#define FC_STALE_S 5.0f
 
 typedef enum {
     STATUS_LIVE,
@@ -88,9 +88,12 @@ typedef enum {
     STATUS_NO_SIGNAL
 } status_t;
 
-static status_t compute_status(double now, double link_t, double fc_t) {
+static status_t compute_status(double now, double link_t, double fc_t,
+                                int has_link, uint8_t up_lq) {
     if (link_t == 0 || (now - link_t) > LINK_STALE_S)
         return STATUS_NO_SIGNAL;
+    if (has_link && up_lq == 0)
+        return STATUS_NO_LINK;
     if (fc_t > 0 && (now - fc_t) > FC_STALE_S)
         return STATUS_STALE;
     return STATUS_LIVE;
@@ -152,6 +155,7 @@ typedef struct {
     /* Counts */
     int rx_frames;
     int unknown;
+    uint32_t type_counts[256]; /* indexed by raw CRSF frame type byte */
 } dashboard_t;
 
 static void dashboard_init(dashboard_t* d) {
@@ -167,15 +171,15 @@ static void dashboard_update(dashboard_t* d, cel_telemetry const* telem,
             d->up_rssi1 = telem->data.link.uplink_rssi1;
             d->up_rssi2 = telem->data.link.uplink_rssi2;
             d->up_lq = telem->data.link.uplink_quality;
-            d->up_snr = telem->data.link.uplink_snr - 128;
+            d->up_snr = telem->data.link.uplink_snr;
             d->power_idx = telem->data.link.uplink_power;
             d->rf_mode = telem->data.link.rf_mode;
             d->link_t = now;
             break;
         case CEL_TELEM_BATTERY:
             d->has_batt = 1;
-            d->batt_v = telem->data.battery.voltage_mv / 1000.0f;
-            d->batt_a = telem->data.battery.current_ma / 1000.0f;
+            d->batt_v = telem->data.battery.voltage_x10 / 10.0f;
+            d->batt_a = telem->data.battery.current_x10 / 10.0f;
             d->batt_mah = telem->data.battery.capacity_mah;
             d->batt_pct = telem->data.battery.remaining_pct;
             d->batt_t = now;
@@ -227,6 +231,34 @@ static void rssi_color(double dbm) {
     else ansi_red();
 }
 
+/* Raw CRSF frame type byte -> name, for diagnostics.
+   Returns NULL for types not in cel_crsf_type. */
+static char const* crsf_type_name(uint8_t type) {
+    switch (type) {
+        case CEL_CRSF_TYPE_GPS:                return "GPS";
+        case CEL_CRSF_TYPE_VARIO:               return "VARIO";
+        case CEL_CRSF_TYPE_BATTERY:             return "BATTERY";
+        case CEL_CRSF_TYPE_BARO_ALT:            return "BARO_ALT";
+        case CEL_CRSF_TYPE_AIRSPEED:            return "AIRSPEED";
+        case CEL_CRSF_TYPE_HEARTBEAT:           return "HEARTBEAT";
+        case CEL_CRSF_TYPE_RPM:                 return "RPM";
+        case CEL_CRSF_TYPE_TEMP:                return "TEMP";
+        case CEL_CRSF_TYPE_VOLTAGES:            return "VOLTAGES";
+        case CEL_CRSF_TYPE_ESC_SENSOR:          return "ESC_SENSOR";
+        case CEL_CRSF_TYPE_LINK_STATS:          return "LINK_STATS";
+        case CEL_CRSF_TYPE_RC_CHANNELS:         return "RC_CHANNELS";
+        case CEL_CRSF_TYPE_ATTITUDE:            return "ATTITUDE";
+        case CEL_CRSF_TYPE_FLIGHT_MODE:         return "FLIGHT_MODE";
+        case CEL_CRSF_TYPE_DEVICE_PING:         return "DEVICE_PING";
+        case CEL_CRSF_TYPE_DEVICE_INFO:         return "DEVICE_INFO";
+        case CEL_CRSF_TYPE_PARAM_ENTRY:         return "PARAM_ENTRY";
+        case CEL_CRSF_TYPE_PARAM_READ:          return "PARAM_READ";
+        case CEL_CRSF_TYPE_PARAM_WRITE:         return "PARAM_WRITE";
+        case CEL_CRSF_TYPE_ELRS_STATUS:         return "ELRS_STATUS";
+        default:                                return NULL;
+    }
+}
+
 /* --------------------------------------------------------------------------- */
 /* Dashboard render - tracks line count for in-place redraw                    */
 /* --------------------------------------------------------------------------- */
@@ -235,7 +267,8 @@ static void render_dashboard(dashboard_t const* d,
                               char const* port, int baud,
                               double elapsed, int* lines) {
     double now = (double)time(NULL);
-    status_t status = compute_status(now, d->link_t, d->fc_t);
+    status_t status = compute_status(now, d->link_t, d->fc_t,
+                                      d->has_link, d->up_lq);
 
     /* Return to top of dashboard if already drawn */
     if (*lines > 0) {
@@ -286,7 +319,7 @@ static void render_dashboard(dashboard_t const* d,
         if (d->batt_v > 3.0f) ansi_green(); else ansi_red();
         printf("%.2fV ", d->batt_v);
         ansi_reset();
-        printf("%.1fA %dmah %d%%", d->batt_a, d->batt_mah, d->batt_pct);
+        printf("%.1fA %umah %d%%", d->batt_a, d->batt_mah, d->batt_pct);
         print_age(now, d->batt_t);
     } else {
         ansi_dim(); printf("waiting..."); ansi_reset();
@@ -326,6 +359,36 @@ static void render_dashboard(dashboard_t const* d,
     printf("\n");
     n++;
 
+    /* Frame type breakdown (top 6 by count) */
+    ansi_clear_line();
+    ansi_dim();
+    printf("  types:");
+    uint8_t used[256] = {0};
+    int shown = 0;
+    for (int k = 0; k < 6; k++) {
+        int best = -1;
+        uint32_t best_count = 0;
+        for (int t = 0; t < 256; t++) {
+            if (!used[t] && d->type_counts[t] > best_count) {
+                best_count = d->type_counts[t];
+                best = t;
+            }
+        }
+        if (best < 0) break;
+        used[best] = 1;
+        char const* name = crsf_type_name((uint8_t)best);
+        if (name != NULL) {
+            printf("  %s=%u", name, best_count);
+        } else {
+            printf("  0x%02X=%u", best, best_count);
+        }
+        shown++;
+    }
+    if (shown == 0) printf(" -");
+    ansi_reset();
+    printf("\n");
+    n++;
+
     *lines = n;
     fflush(stdout);
 }
@@ -361,11 +424,13 @@ static int list_ports(void) {
 
 /* Send a ping and wait for DEVICE_INFO to verify the module responds. */
 static int verify_connection(cel_serial_port* port) {
-    if (cel_crsf_param_ping(port, 2.0f) != 0) {
-        cel_log_warn("No DEVICE_INFO response - module may not be connected");
-        return -1;
+    /* The module may take a few seconds to respond to the first ping,
+     * so retry a few times before giving up. */
+    for (int attempt = 0; attempt < 3; attempt++) {
+        if (cel_crsf_param_ping(port, 2.0f) == 0) return 0;
     }
-    return 0;
+    cel_log_warn("No DEVICE_INFO response - module may not be connected");
+    return -1;
 }
 
 int main(int argc, char const* argv[]) {
@@ -453,6 +518,7 @@ int main(int argc, char const* argv[]) {
 
             double now = (double)time(NULL);
             for (int i = 0; i < n; i++) {
+                dash.type_counts[frames[i].type]++;
                 cel_telemetry telem;
                 if (cel_crsf_telemetry_parse(&frames[i], &telem) == 0) {
                     dashboard_update(&dash, &telem, now);
@@ -469,6 +535,14 @@ int main(int argc, char const* argv[]) {
             cel_serial_write(port, rc_buf, rc_len);
         }
 
+        /* Send DEVICE_PING every 5s so DEVICE_INFO replies keep showing up
+         * in the dashboard's type_counts, like the Python ping_loop. */
+        if (rc_count % 250 == 0) {
+            uint8_t ping_buf[8];
+            size_t ping_len = cel_crsf_build_ping_frame(ping_buf);
+            cel_serial_write(port, ping_buf, ping_len);
+        }
+
         /* Redraw dashboard every 100 ms */
         if (rc_count % 5 == 0) {
             double elapsed = difftime(time(NULL), t_start);