Implement timeslot mechanism for renard sync

4 files changed, 106 insertions, 13 deletions

diff --git a/src/testapp1/README.md b/src/testapp1/README.md
index 7099b6a..92c8206 100644
--- a/src/testapp1/README.md
+++ b/src/testapp1/README.md
@@ -1,5 +1,26 @@
 testapp1
 ========
 
-This only sends MOS in morse code on PB0
+On startup, transmit callsign, then start transmitting CW codes:
+
++--------+-----------+
+| sign   | timeslot  |
++--------+-----------+
+|  E     |     1     |
+|  I     |     2     |
+|  S     |     3     |
+|  H     |     4     |
+|  err   | permanent |
++--------+-----------+
+
+CW is output on PB0, noninverted logic.
+
+When SYNCn input on PB2 goes to zero, transmission stops, and the internal time is set to 0.
+
+Modes
+-----
+
+When internal time < 10 minutes, transmit only sign without "MO", in short timeslots, then stay silent 30s.
+
+If internal time >= 10 minutes, transmit "MO<sign>" for a full minute timeslot.
 
diff --git a/src/testapp1/main.c b/src/testapp1/main.c
index b305372..117551a 100644
--- a/src/testapp1/main.c
+++ b/src/testapp1/main.c
@@ -6,18 +6,45 @@
 #include "delay.h"
 #include "morse.h"
 
-
+/* Definitions for pins */
 #define PORTB_PTT (1 << 0)
+#define PORTB_SYNCn (1 << 2)
 #define PORTB_LED (1 << 4)
 
-volatile uint8_t Timer;        /* Timer (100Hz increment) */
+/* Specify ID here */
+static const uint8_t renard_id = 0;
+
+static const uint8_t num_renards_cycle = 4;
+// colon (:) represents ERROR
+static const char letters[] = "eish:";
+static const char unique_letter = letters[renard_id];
+
+volatile uint8_t reset_time;
+volatile uint8_t systick;        /* Timer (100Hz increment) */
+volatile uint8_t seconds;
+volatile uint16_t minutes;
 
 /*---------------------------------------------------------*/
 /* 100Hz timer interrupt generated by OC2                  */
 /*---------------------------------------------------------*/
 ISR(TIMER1_COMPA_vect)
 {
-    Timer++;
+    systick++;
+    if (systick == 10) {
+        systick = 0;
+        seconds += 1;
+    }
+
+    if (seconds == 60) {
+        seconds = 0;
+        minutes++;
+    }
+
+    if (reset_time) {
+        reset_time = 0;
+        seconds = 0;
+        minutes = 0;
+    }
 }
 
 static int inittimer(void)
@@ -76,6 +103,11 @@ void dit(void)
 
 int main(void)
 {
+    systick = 0;
+    seconds = 0;
+    minutes = 0;
+    reset_time = 0;
+
     /* Enable PTT output on PB0 */
 #if PTT_LOGIC_LOW
     PORTB = PORTB_PTT;
@@ -86,14 +118,45 @@ int main(void)
     /* initialise timer interrupt */
     inittimer();
 
+    static char *morse_string = "MO ";
+    morse_string[2] = unique_letter;
+
+    const int permanent = (unique_letter == ':');
+
     delay_ms(12*DIT_DURATION);
-    morse("HB9EGM");
+    morse("HB9HI");
     delay_ms(12*DIT_DURATION);
 
     while (1) {
-        // morse code !
-        morse("MOH");
-        delay_ms(6*DIT_DURATION);
+        if ((PINB & PORTB_SYNCn) == 0) {
+            reset_time = 1;
+        }
+
+        if (permanent) {
+            morse(morse_string);
+            delay_ms(6*DIT_DURATION);
+        }
+        else if (minutes >= 10) { // see README.md
+            /* renard id 0: start at (k * num_renards_cycle) * 60, end at (k * num_renards_cycle) * 60 + 55 */
+            const int in_timeslot = (minutes % num_renards_cycle) == renard_id;
+
+            if (in_timeslot && seconds < 55) {
+                morse(morse_string);
+                delay_ms(6*DIT_DURATION);
+            }
+            else {
+                delay_ms(DIT_DURATION);
+            }
+        }
+        else {
+            /* renard id 0: start every 30s, with an additional 2s offset depending on renard_id */
+            const uint32_t second_offset = seconds % 30;
+
+            if (second_offset == 2 * renard_id) {
+                morse_char(unique_letter);
+                delay_ms(1000); // avoid retrigger in same second
+            }
+        }
     }
 
     return 0;
diff --git a/src/testapp1/morse.c b/src/testapp1/morse.c
index cb06b4a..65b27cd 100644
--- a/src/testapp1/morse.c
+++ b/src/testapp1/morse.c
@@ -6,7 +6,7 @@
 #include "delay.h"
 #include "morse.h"
 
-const uint8_t morse_mapping[60] PROGMEM =
+const uint16_t morse_mapping[60] PROGMEM =
 {
     // Read bits from right to left
 
@@ -28,10 +28,12 @@ const uint8_t morse_mapping[60] PROGMEM =
     0b111000,
     0b110000, // 9, ASCII 57
 
+    // the colon stands in as error
+    0b111111111, // :
+
     // The following are mostly invalid, but
     // required to fill the gap in ASCII between
     // numerals and capital letters
-    0b10, // :
     0b10, // ;
     0b10, // <
     0b10, // =
@@ -90,9 +92,6 @@ void morse_symbol(uint8_t sym)
     delay_ms(4*DIT_DURATION);
 }
 
-// Transmit a string in morse code. Supported range:
-// All ASCII between '+' and '\', which includes
-// numerals and capital letters.
 void morse(char* text)
 {
     char* sym = text;
@@ -102,3 +101,7 @@ void morse(char* text)
     } while (*sym != '\0');
 }
 
+void morse_char(char letter)
+{
+    morse_symbol(letter - '+');
+}
diff --git a/src/testapp1/morse.h b/src/testapp1/morse.h
index 68cebb1..b2c78db 100644
--- a/src/testapp1/morse.h
+++ b/src/testapp1/morse.h
@@ -3,7 +3,13 @@
 
 #define DIT_DURATION 100 // ms
 
+// Transmit a string or a single char in morse code.
+//
+// Supported range:
+// All ASCII between '+' and '\', which includes
+// numerals and capital letters.
 void morse(char* text);
+void morse_char(char letter);
 
 void dah(void);
 void dit(void);