diff options
| -rw-r--r-- | src/cw-example/audio.h | 3 | ||||
| -rw-r--r-- | src/cw-example/cw.c | 169 | ||||
| -rw-r--r-- | src/cw-example/main.c | 1 |
3 files changed, 83 insertions, 90 deletions
diff --git a/src/cw-example/audio.h b/src/cw-example/audio.h index 31cb0fe..35f3f65 100644 --- a/src/cw-example/audio.h +++ b/src/cw-example/audio.h @@ -15,6 +15,9 @@ typedef void AudioCallbackFunction(void *context,int buffer); #define Audio44100HzSettings 271,2,6,0 #define AudioVGAHSyncSettings 419,2,13,0 // 31475.3606. Actual VGA timer is 31472.4616. +#define AUDIO_BUF_LEN 4096 + + // Initialize and power up audio hardware. Use the above defines for the parameters. // Can probably only be called once. void InitializeAudio(int plln,int pllr,int i2sdiv,int i2sodd); diff --git a/src/cw-example/cw.c b/src/cw-example/cw.c index 02e65d3..3b9df43 100644 --- a/src/cw-example/cw.c +++ b/src/cw-example/cw.c @@ -22,6 +22,17 @@ * SOFTWARE. */ +/* CW generator + * + * Concept: + * + * +-------------------+ +-----------+ + * | cw_push_message() | -> cw_msg_queue -> | cw_task() | -> cw_audio_queue + * +-------------------+ +-----------+ + * + * The cw_fill_buffer() function can be called to fetch audio from the audio_queue + */ + #include "cw.h" #include "arm_math.h" #include "audio.h" @@ -29,6 +40,7 @@ /* Kernel includes. */ #include "FreeRTOS.h" +#include "task.h" #include "queue.h" #include "semphr.h" @@ -45,30 +57,35 @@ struct cw_out_message_s { }; // The queue contains above structs -QueueHandle_t cw_queue; -static int cw_samplerate; - -// The message being currently handled by cw_fill_buffer -static struct cw_out_message_s cw_fill_msg_current; -// Set to 1 if the cw_fill_buffer function is currently handling -// msg_current. 0 if it has to wait for a new message. -static int cw_fill_msg_status; +QueueHandle_t cw_msg_queue; -// Keep track of number of audio samples that were already -// generated from the current message -static int cw_fill_audio_sent; +// Queue that contains audio data +QueueHandle_t cw_audio_queue; +static int cw_samplerate; +static void cw_task(void *pvParameters); void cw_init(unsigned int samplerate) { cw_samplerate = samplerate; - cw_fill_msg_status = 0; + cw_msg_queue = xQueueCreate(15, sizeof(struct cw_out_message_s)); + if (cw_msg_queue == 0) { + while(1); /* fatal error */ + } - cw_queue = xQueueCreate(15, sizeof(struct cw_out_message_s)); - if (cw_queue == 0) { + cw_audio_queue = xQueueCreate(2, AUDIO_BUF_LEN * sizeof(int16_t)); + if (cw_audio_queue == 0) { while(1); /* fatal error */ } + + xTaskCreate( + cw_task, + "TaskCW", + 8*configMINIMAL_STACK_SIZE, + (void*) NULL, + tskIDLE_PRIORITY + 2UL, + NULL); } const uint8_t cw_mapping[60] = { // {{{ @@ -165,9 +182,9 @@ void cw_symbol(uint8_t sym, struct cw_out_message_s *msg) p++; } - // silence(4) - if (msg->on_buffer_end + 4 < ON_BUFFER_SIZE) { - for (int i = 0; i < 4; i++) { + // silence(2) + if (msg->on_buffer_end + 2 < ON_BUFFER_SIZE) { + for (int i = 0; i < 2; i++) { msg->on_buffer[msg->on_buffer_end++] = 0; } } @@ -189,8 +206,8 @@ void cw_push_message(const char* text, int dit_duration, int frequency) const char* sym = text; do { if (*sym < '+' || *sym > '\\') { - if (msg.on_buffer_end + 4 < ON_BUFFER_SIZE) { - for (int i = 0; i < 4; i++) { + if (msg.on_buffer_end + 3 < ON_BUFFER_SIZE) { + for (int i = 0; i < 3; i++) { msg.on_buffer[msg.on_buffer_end++] = 0; } } @@ -201,95 +218,69 @@ void cw_push_message(const char* text, int dit_duration, int frequency) sym++; } while (*sym != '\0'); - xQueueSendToBack(cw_queue, &msg, 0); /* Send Message */ + xQueueSendToBack(cw_msg_queue, &msg, portMAX_DELAY); /* Send Message */ } size_t cw_fill_buffer(int16_t *buf, size_t bufsize) { - static float nco_phase = 0.0f; - - - if (cw_fill_msg_status == 0) { - int waiting = uxQueueMessagesWaitingFromISR(cw_queue); -#if 1 - if (waiting > 0 && - xQueueReceiveFromISR(cw_queue, &cw_fill_msg_current, NULL)) { - // Convert msg to audio samples and transmit - cw_fill_msg_status = 1; - cw_fill_audio_sent = 0; - } - else { - return 0; - } -#else + if (xQueueReceiveFromISR(cw_audio_queue, buf, NULL)) { + return bufsize; + } + else { return 0; -#endif } +} -#if 1 - const int samples_per_dit = (cw_samplerate * 10) / - cw_fill_msg_current.dit_duration; - - // Angular frequency of NCO - const float omega = 2.0f * FLOAT_PI * cw_fill_msg_current.freq / - (float)cw_samplerate; +static int16_t cw_audio_buf[AUDIO_BUF_LEN]; +static void cw_task(void *pvParameters) +{ + struct cw_out_message_s cw_fill_msg_current; - // Define start point - int start_i = cw_fill_audio_sent / samples_per_dit; - int start_t = cw_fill_audio_sent % samples_per_dit; + float nco_phase = 0.0f; - int pos = 0; + int buf_pos = 0; - for (int i = start_i; i < cw_fill_msg_current.on_buffer_end; i++) { + while (1) { + int status = xQueueReceive(cw_msg_queue, &cw_fill_msg_current, portMAX_DELAY); + if (status == pdTRUE) { - for (int t = start_t; t < samples_per_dit; t++) { - int16_t s = 0; + const int samples_per_dit = (cw_samplerate * 10) / + cw_fill_msg_current.dit_duration; - if (cw_fill_msg_current.on_buffer[i]) { - nco_phase += omega; - if (nco_phase > FLOAT_PI) { - nco_phase -= 2.0f * FLOAT_PI; - } + // Angular frequency of NCO + const float omega = 2.0f * FLOAT_PI * cw_fill_msg_current.freq / + (float)cw_samplerate; - s = 32768.0f * arm_sin_f32(nco_phase); - } + for (int i = 0; i < cw_fill_msg_current.on_buffer_end; i++) { + for (int t = 0; t < samples_per_dit; t++) { + int16_t s = 0; - if (pos + 2 >= bufsize) { - goto cw_fill_buf_full; - } + if (cw_fill_msg_current.on_buffer[i]) { + nco_phase += omega; + if (nco_phase > FLOAT_PI) { + nco_phase -= 2.0f * FLOAT_PI; + } - // Stereo - buf[pos++] = s; - buf[pos++] = s; + s = 32768.0f * arm_sin_f32(nco_phase); + } - cw_fill_audio_sent += 2; - } + if (buf_pos == AUDIO_BUF_LEN) { + xQueueSendToBack(cw_audio_queue, &cw_audio_buf, portMAX_DELAY); + buf_pos = 0; + } + cw_audio_buf[buf_pos++] = s; - start_t = 0; - } - - // We have completed this message - cw_fill_msg_status = 0; - -cw_fill_buf_full: -#else - const float omega = 2.0f * FLOAT_PI * 300.0f / - (float)cw_samplerate; - - for (int t = 0; t < bufsize; t++) { - int16_t s = 0; + // Stereo + if (buf_pos == AUDIO_BUF_LEN) { + xQueueSendToBack(cw_audio_queue, &cw_audio_buf, portMAX_DELAY); + buf_pos = 0; + } + cw_audio_buf[buf_pos++] = s; + } + } - nco_phase += omega; - if (nco_phase > FLOAT_PI) { - nco_phase -= 2.0f * FLOAT_PI; + // We have completed this message } - - // TODO preserve oscillator phase - s = 32768.0f * arm_sin_f32(nco_phase); - - buf[t] = s; } -#endif - return bufsize; } diff --git a/src/cw-example/main.c b/src/cw-example/main.c index 2b19177..ba0e9c0 100644 --- a/src/cw-example/main.c +++ b/src/cw-example/main.c @@ -108,7 +108,6 @@ static void detect_button_press(void *pvParameters) } } -#define AUDIO_BUF_LEN 4096 static void audio_callback(void* context, int select_buffer) { static int16_t audio_buffer0[AUDIO_BUF_LEN]; |