diff options
Diffstat (limited to 'src/fsm/cw.c')
| -rw-r--r-- | src/fsm/cw.c | 334 |
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; } |