From fdc2fed5e36a5390b26a763285edc17fa63c3200 Mon Sep 17 00:00:00 2001
From: c vw <dl1ycf@darc.de>
Date: Wed, 24 Feb 2021 19:06:34 +0100
Subject: [PATCH] Implemented "TX fifo underrun/overrun" indication on TX
 panadapter for HermesLite-II.

---
 old_protocol.c  | 30 ++++++++++++++++++++++++------
 radio.c         |  4 ++++
 radio.h         |  2 ++
 tx_panadapter.c | 20 ++++++++++++++++++++
 4 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/old_protocol.c b/old_protocol.c
index af01f7f..47cb757 100644
--- a/old_protocol.c
+++ b/old_protocol.c
@@ -142,6 +142,7 @@ static long ep4_sequence;
 
 static uint32_t last_seq_num=-0xffffffff;
 static int suppress_ozy_packet = 0;
+static int tx_fifo_flag = 0;
 
 static int current_rx=0;
 
@@ -1111,12 +1112,29 @@ static void process_control_bytes() {
       // As a result, we set the "TX latency" to 40 msec (see below).
       //
       //
-      //if (device == DEVICE_HERMES_LITE2 && isTransmitting()) {
-      //   fprintf(stderr,"TX FIFO: %d", control_in[3] & 0x7F);
-      //   if ((control_in[3] & 0xC0) == 0xC0) fprintf(stderr," OVER ");
-      //   if ((control_in[3] & 0xC0) == 0x80) fprintf(stderr," UNDER ");
-      //   fprintf(stderr,"\n");
-      //}
+      // Note after an RX/TX transition, "underflow" is reported
+      // until the TX fifo begins to fill, so we ignore underflows
+      // until the first packet reporting "no underflow" after each
+      // RX/TX transition.
+      //
+      if (device == DEVICE_HERMES_LITE2) {
+           if (!isTransmitting()) {
+              // during RX: set flag to zero
+              tx_fifo_flag=0;
+           } else {
+             // after RX/TX transition: ignore underflow condition
+             // until it first vanishes. tx_fifo_flag becomes "true"
+             // as soon as a "no underflow" condition is seen.
+             //
+             //fprintf(stderr,"TX FIFO: %d", control_in[3] & 0x7F);
+             //if ((control_in[3] & 0xC0) == 0xC0) fprintf(stderr," OVER ");
+             //if ((control_in[3] & 0xC0) == 0x80) fprintf(stderr," UNDER ");
+             //fprintf(stderr,"\n");
+             if ((control_in[3] & 0xC0) != 0x80) tx_fifo_flag=1;
+             if ((control_in[3] & 0xC0) == 0x80 && tx_fifo_flag) tx_fifo_underrun=1;
+             if ((control_in[3] & 0xC0) == 0xC0) tx_fifo_overrun=1;
+           }
+      }
       if(ozy_software_version!=control_in[4]) {
         ozy_software_version=control_in[4];
         g_print("FPGA firmware version: %d.%d\n",ozy_software_version/10,ozy_software_version%10);
diff --git a/radio.c b/radio.c
index 501cb1c..4e4b511 100644
--- a/radio.c
+++ b/radio.c
@@ -253,6 +253,8 @@ unsigned int n_temperature;
 unsigned int current;
 unsigned int average_current;
 unsigned int n_current;
+unsigned int tx_fifo_underrun;
+unsigned int tx_fifo_overrun;
 unsigned int alex_forward_power;
 unsigned int alex_reverse_power;
 unsigned int AIN3;
@@ -1181,6 +1183,8 @@ void start_radio() {
   n_temperature=0;
   current=0;
   average_current=0;
+  tx_fifo_underrun=0;
+  tx_fifo_overrun=0;
   n_current=0;
 
   display_sequence_errors=TRUE;
diff --git a/radio.h b/radio.h
index 74b4e8a..9b322cc 100644
--- a/radio.h
+++ b/radio.h
@@ -244,6 +244,8 @@ extern unsigned int n_temperature;
 extern unsigned int current;
 extern unsigned int average_current;
 extern unsigned int n_current;
+extern unsigned int tx_fifo_underrun;
+extern unsigned int tx_fifo_overrun;
 extern unsigned int alex_forward_power;
 extern unsigned int alex_reverse_power;
 extern unsigned int IO1;
diff --git a/tx_panadapter.c b/tx_panadapter.c
index dae2b55..4ca7870 100644
--- a/tx_panadapter.c
+++ b/tx_panadapter.c
@@ -49,6 +49,7 @@ static gdouble hz_per_pixel;
 static gdouble filter_left=0.0;
 static gdouble filter_right=0.0;
 
+static gint tx_fifo_count=0;
 
 /* Create a new surface of the appropriate size to store our scribbles */
 static gboolean
@@ -442,6 +443,25 @@ void tx_panadapter_update(TRANSMITTER *tx) {
     sprintf(text,"%0.0fmA",c);
     cairo_move_to(cr, 160.0, 30.0);
     cairo_show_text(cr, text);
+
+    if (tx_fifo_overrun || tx_fifo_underrun) {
+      cairo_set_source_rgb(cr,1.0,0.0,0.0);
+      if (tx_fifo_underrun) {
+        cairo_move_to(cr, 220.0, 30.0);
+        cairo_show_text(cr, "Underrun");
+      }
+      if (tx_fifo_overrun) {
+        cairo_move_to(cr, 300.0, 30.0);
+        cairo_show_text(cr, "Overrun");
+      }
+      // display for 2 seconds
+      tx_fifo_count++;
+      if (tx_fifo_count >= 2*tx->fps) {
+        tx_fifo_underrun=0;
+        tx_fifo_overrun=0;
+        tx_fifo_count=0;
+      }
+    }
   }
 
   cairo_destroy (cr);
-- 
2.45.2