aboutsummaryrefslogtreecommitdiffstats
path: root/src/fsm/cw.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/fsm/cw.c')
-rw-r--r--src/fsm/cw.c334
1 files changed, 286 insertions, 48 deletions
diff --git a/src/fsm/cw.c b/src/fsm/cw.c
index 654df22..f3d4335 100644
--- a/src/fsm/cw.c
+++ b/src/fsm/cw.c
@@ -22,15 +22,16 @@
* SOFTWARE.
*/
-/* CW generator
+/* CW and PSK31 generator
*
* Concept:
*
- * +-------------------+ +-----------+
- * | cw_push_message() | -> cw_msg_queue -> | cw_task() | -> cw_audio_queue
- * +-------------------+ +-----------+
+ * +-------------------+ +----------------+
+ * | cw_push_message() | -> cw_msg_queue -> | cw_psk31task() | -> cw_audio_queue
+ * +-------------------+ +----------------+
*
- * The cw_fill_buffer() function can be called to fetch audio from the audio_queue
+ * The cw_psk31_fill_buffer() function can be called to fetch audio from the
+ * audio_queue
*/
#include "cw.h"
@@ -111,12 +112,150 @@ const uint8_t cw_mapping[60] = { // {{{
0b1010111, // SK , ASCII '\'
}; //}}}
+/*
+ * PSK31 Varicode
+ * http://aintel.bi.ehu.es/psk31.html
+ */
+const char *psk31_varicode[] = { // {{{
+ "1010101011",
+ "1011011011",
+ "1011101101",
+ "1101110111",
+ "1011101011",
+ "1101011111",
+ "1011101111",
+ "1011111101",
+ "1011111111",
+ "11101111",
+ "11101",
+ "1101101111",
+ "1011011101",
+ "11111",
+ "1101110101",
+ "1110101011",
+ "1011110111",
+ "1011110101",
+ "1110101101",
+ "1110101111",
+ "1101011011",
+ "1101101011",
+ "1101101101",
+ "1101010111",
+ "1101111011",
+ "1101111101",
+ "1110110111",
+ "1101010101",
+ "1101011101",
+ "1110111011",
+ "1011111011",
+ "1101111111",
+ "1",
+ "111111111",
+ "101011111",
+ "111110101",
+ "111011011",
+ "1011010101",
+ "1010111011",
+ "101111111",
+ "11111011",
+ "11110111",
+ "101101111",
+ "111011111",
+ "1110101",
+ "110101",
+ "1010111",
+ "110101111",
+ "10110111",
+ "10111101",
+ "11101101",
+ "11111111",
+ "101110111",
+ "101011011",
+ "101101011",
+ "110101101",
+ "110101011",
+ "110110111",
+ "11110101",
+ "110111101",
+ "111101101",
+ "1010101",
+ "111010111",
+ "1010101111",
+ "1010111101",
+ "1111101",
+ "11101011",
+ "10101101",
+ "10110101",
+ "1110111",
+ "11011011",
+ "11111101",
+ "101010101",
+ "1111111",
+ "111111101",
+ "101111101",
+ "11010111",
+ "10111011",
+ "11011101",
+ "10101011",
+ "11010101",
+ "111011101",
+ "10101111",
+ "1101111",
+ "1101101",
+ "101010111",
+ "110110101",
+ "101011101",
+ "101110101",
+ "101111011",
+ "1010101101",
+ "111110111",
+ "111101111",
+ "111111011",
+ "1010111111",
+ "101101101",
+ "1011011111",
+ "1011",
+ "1011111",
+ "101111",
+ "101101",
+ "11",
+ "111101",
+ "1011011",
+ "101011",
+ "1101",
+ "111101011",
+ "10111111",
+ "11011",
+ "111011",
+ "1111",
+ "111",
+ "111111",
+ "110111111",
+ "10101",
+ "10111",
+ "101",
+ "110111",
+ "1111011",
+ "1101011",
+ "11011111",
+ "1011101",
+ "111010101",
+ "1010110111",
+ "110111011",
+ "1010110101",
+ "1011010111",
+ "1110110101",
+}; //}}}
+
+
struct cw_message_s {
- char message[MAX_MESSAGE_LEN];
- size_t message_len;
+ char message[MAX_MESSAGE_LEN];
+ size_t message_len;
+
+ int freq;
- int freq;
- int dit_duration;
+ // If dit_duration is 0, the message is sent in PSK31
+ int dit_duration;
};
// The queue contains above structs
@@ -124,15 +263,15 @@ QueueHandle_t cw_msg_queue;
// Queue that contains audio data
QueueHandle_t cw_audio_queue;
-static int cw_samplerate;
+static int cw_psk31_samplerate;
static int cw_transmit_ongoing;
-static void cw_task(void *pvParameters);
+static void cw_psk31_task(void *pvParameters);
-void cw_init(unsigned int samplerate)
+void cw_psk31_init(unsigned int samplerate)
{
- cw_samplerate = samplerate;
+ cw_psk31_samplerate = samplerate;
cw_transmit_ongoing = 0;
cw_msg_queue = xQueueCreate(15, sizeof(struct cw_message_s));
@@ -146,8 +285,8 @@ void cw_init(unsigned int samplerate)
}
xTaskCreate(
- cw_task,
- "TaskCW",
+ cw_psk31_task,
+ "CWPSKTask",
8*configMINIMAL_STACK_SIZE,
(void*) NULL,
tskIDLE_PRIORITY + 2UL,
@@ -199,13 +338,19 @@ size_t cw_symbol(uint8_t sym, uint8_t *on_buffer, size_t on_buffer_size)
return pos;
}
-// Transmit a string in morse code. Supported range:
+// Transmit a string in morse code or PSK31.
+// Supported range for CW:
// All ASCII between '+' and '\', which includes
// numerals and capital letters.
-void cw_push_message(const char* text, int dit_duration, int frequency)
+// Distinction between CW and PSK31 is done on dit_duration==0
+int cw_psk31_push_message(const char* text, int dit_duration, int frequency)
{
const int text_len = strlen(text);
+ if (strlen(text) > MAX_MESSAGE_LEN) {
+ return 0;
+ }
+
struct cw_message_s msg;
for (int i = 0; i < MAX_MESSAGE_LEN; i++) {
if (i < text_len) {
@@ -220,12 +365,14 @@ void cw_push_message(const char* text, int dit_duration, int frequency)
msg.dit_duration = dit_duration;
xQueueSendToBack(cw_msg_queue, &msg, portMAX_DELAY); /* Send Message */
+
+ return 1;
}
/* Parse the message and fill the on_buffer with CW on/CW off information.
* Returns the number of on/off bits written.
*/
-size_t cw_text_to_on_buffer(const char *msg, uint8_t *on_buffer, size_t on_buffer_size)
+static size_t cw_text_to_on_buffer(const char *msg, uint8_t *on_buffer, size_t on_buffer_size)
{
size_t pos = 0;
const char* sym = msg;
@@ -246,7 +393,44 @@ size_t cw_text_to_on_buffer(const char *msg, uint8_t *on_buffer, size_t on_buffe
return pos;
}
-size_t cw_fill_buffer(int16_t *buf, size_t bufsize)
+/*
+ * Turn a null terminated ASCII string into a uint8_t buffer
+ * of 0 and 1 representing the PSK31 varicode for the input.
+ *
+ * outstr must be at least size 20 + strlen(instr)*12 + 20 to accomodate
+ * the header and tail.
+ *
+ * Returns number of bytes written.
+ */
+static size_t psk31_text_to_phase_buffer(const char* instr, uint8_t* outbits)
+{
+ int i=0, j, k;
+
+ /* Header of 0s */
+ for (j=0; j < 20; j++) {
+ outbits[i++] = '0';
+ }
+
+ /* Encode the message, with 00 between letters */
+ for (j=0; j < strlen(instr); j++) {
+ const char* varicode_bits = psk31_varicode[(int)instr[j]];
+ for(k=0; k < strlen(varicode_bits); k++) {
+ outbits[i++] = (varicode_bits[k] == '1') ? 1 : 0;
+ }
+ outbits[i++] = 0;
+ outbits[i++] = 0;
+ }
+
+ /* Tail of 0s */
+ for (j=0; j < 20; j++) {
+ outbits[i++] = 0;
+ }
+
+ return i;
+}
+
+
+size_t cw_psk31_fill_buffer(int16_t *buf, size_t bufsize)
{
if (xQueueReceiveFromISR(cw_audio_queue, buf, NULL)) {
return bufsize;
@@ -257,52 +441,102 @@ size_t cw_fill_buffer(int16_t *buf, size_t bufsize)
}
static int16_t cw_audio_buf[AUDIO_BUF_LEN];
-static uint8_t cw_on_buffer[MAX_ON_BUFFER_LEN];
+static uint8_t cw_psk31_buffer[MAX_ON_BUFFER_LEN];
static struct cw_message_s cw_fill_msg_current;
-static void cw_task(void *pvParameters)
+
+// Routine to generate CW audio
+static float cw_generate_audio_ampl = 0.0f;
+static float cw_generate_audio_nco = 0.0f;
+static int16_t cw_generate_audio(float omega, int i, int t)
{
- float nco_phase = 0.0f;
- float ampl = 0.0f;
+ int16_t s = 0;
+ // Remove clicks from CW
+ if (cw_psk31_buffer[i]) {
+ const float remaining = 32768.0f - cw_generate_audio_ampl;
+ cw_generate_audio_ampl += remaining / 64.0f;
+ }
+ else {
+ cw_generate_audio_ampl -= cw_generate_audio_ampl / 64.0f;
+ }
+
+ cw_generate_audio_nco += omega;
+ if (cw_generate_audio_nco > FLOAT_PI) {
+ cw_generate_audio_nco -= 2.0f * FLOAT_PI;
+ }
+
+ s = cw_generate_audio_ampl * arm_sin_f32(cw_generate_audio_nco);
+ return s;
+}
+
+static float psk31_generate_audio_nco = 0.0f;
+static int psk31_current_psk_phase = 1;
+static int16_t psk31_generate_audio(float omega, int i, int t, int samples_per_symbol)
+{
+ int16_t s = 0;
+ const float base_ampl = 20000.0f;
+ float psk31_generate_audio_ampl = 0.0f;
+
+ if (cw_psk31_buffer[i] == 1) {
+ psk31_generate_audio_ampl = base_ampl;
+ }
+ else {
+ psk31_generate_audio_ampl = base_ampl * arm_cos_f32(
+ FLOAT_PI*(float)t/(float)samples_per_symbol);
+ }
+
+ psk31_generate_audio_nco += omega;
+ if (psk31_generate_audio_nco > FLOAT_PI) {
+ psk31_generate_audio_nco -= 2.0f * FLOAT_PI;
+ }
+ s = psk31_generate_audio_ampl *
+ arm_sin_f32(psk31_generate_audio_nco +
+ (psk31_current_psk_phase == 1 ? 0.0f : FLOAT_PI));
+
+ return s;
+}
+
+static void cw_psk31_task(void *pvParameters)
+{
int buf_pos = 0;
while (1) {
int status = xQueueReceive(cw_msg_queue, &cw_fill_msg_current, portMAX_DELAY);
if (status == pdTRUE) {
- size_t on_buffer_len = cw_text_to_on_buffer(
- cw_fill_msg_current.message,
- cw_on_buffer,
- MAX_ON_BUFFER_LEN);
+ size_t cw_psk31_buffer_len = 0;
cw_transmit_ongoing = 1;
- const int samples_per_dit =
- (cw_samplerate * cw_fill_msg_current.dit_duration) / 1000;
+ if (cw_fill_msg_current.dit_duration) {
+ cw_psk31_buffer_len = cw_text_to_on_buffer(
+ cw_fill_msg_current.message,
+ cw_psk31_buffer,
+ MAX_ON_BUFFER_LEN);
+
+ }
+ else {
+ cw_psk31_buffer_len = psk31_text_to_phase_buffer(
+ cw_fill_msg_current.message,
+ cw_psk31_buffer);
+ }
// Angular frequency of NCO
const float omega = 2.0f * FLOAT_PI * cw_fill_msg_current.freq /
- (float)cw_samplerate;
+ (float)cw_psk31_samplerate;
- for (int i = 0; i < on_buffer_len; i++) {
- for (int t = 0; t < samples_per_dit; t++) {
- int16_t s = 0;
+ const int samples_per_symbol = (cw_fill_msg_current.dit_duration != 0) ?
+ (cw_psk31_samplerate * cw_fill_msg_current.dit_duration) / 1000 :
+ /* BPSK31 is at 31.25 symbols per second. */
+ cw_psk31_samplerate * 100 / 3125;
- // Remove clicks from CW
- if (cw_on_buffer[i]) {
- const float remaining = 32768.0f - ampl;
- ampl += remaining / 64.0f;
- }
- else {
- ampl -= ampl / 64.0f;
- }
-
- nco_phase += omega;
- if (nco_phase > FLOAT_PI) {
- nco_phase -= 2.0f * FLOAT_PI;
- }
+ psk31_current_psk_phase = 1;
- s = ampl * arm_sin_f32(nco_phase);
+ for (int i = 0; i < cw_psk31_buffer_len; i++) {
+ for (int t = 0; t < samples_per_symbol; t++) {
+ int16_t s = (cw_fill_msg_current.dit_duration != 0) ?
+ cw_generate_audio(omega, i, t) :
+ psk31_generate_audio(omega, i, t, samples_per_symbol);
if (buf_pos == AUDIO_BUF_LEN) {
xQueueSendToBack(cw_audio_queue, &cw_audio_buf, portMAX_DELAY);
@@ -317,6 +551,10 @@ static void cw_task(void *pvParameters)
}
cw_audio_buf[buf_pos++] = s;
}
+
+ if (cw_psk31_buffer[i] == 0) {
+ psk31_current_psk_phase *= -1;
+ }
}
// We have completed this message
@@ -326,7 +564,7 @@ static void cw_task(void *pvParameters)
}
}
-int cw_busy(void)
+int cw_psk31_busy(void)
{
return cw_transmit_ongoing;
}