added spindle effect

CMakeLists.txt

@@ -4,7 +4,7 @@ cmake_minimum_required(VERSION 3.5.0)
 file(GLOB_RECURSE USER_SOURCES "User/*.c")
 file(GLOB_RECURSE MX_SOURCES "Src/*.c")
 file(GLOB_RECURSE HAL_SOURCES "Drivers/STM32F1xx_HAL_Driver/Src/*.c")
-file(GLOB_RECURSE CMSIS_SOURCES "Drivers/CMSIS/DSP_Lib/Source/*.c")
+file(GLOB_RECURSE CMSIS_SOURCES "Drivers/CMSIS/DSP_Lib/Source/*.c" "Drivers/CMSIS/DSP_Lib/Source/*.S")
 
 add_library(HAL ${HAL_SOURCES})
 add_library(CMSIS ${CMSIS_SOURCES}

Src/tim.c

@@ -50,7 +50,7 @@ void MX_TIM3_Init(void)
   htim3.Instance = TIM3;
   htim3.Init.Prescaler = 0;
   htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
-  htim3.Init.Period = 1800;
+  htim3.Init.Period = 3600; //1800;
   htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
   if (HAL_TIM_OC_Init(&htim3) != HAL_OK)
   {

User/user_main.c

@@ -3,20 +3,22 @@
 //
 
 #include <inttypes.h>
-#include <arm_const_structs.h>
 #include <arm_math.h>
+#include <arm_const_structs.h>
 #include <stm32f1xx_hal_gpio.h>
 #include "dotmatrix.h"
-#include "mxconstants.h"
-#include "stm32f1xx_hal.h"
 #include "adc.h"
 #include "tim.h"
 #include "user_main.h"
 #include "debounce.h"
 #include "debug.h"
 
-#define SAMPLE_COUNT 256
+// 512 = show 0-5 kHz
+// 256 = show 0-10 kHz
+// smaller range is OK since we have only a limited reception of higher frequencies anyway
+#define SAMPLE_COUNT 512
 #define BIN_COUNT (SAMPLE_COUNT/2)
+#define CFFT_INST arm_cfft_sR_f32_len256
 
 #define SCREEN_W 32
 #define SCREEN_H 16
@@ -28,20 +30,51 @@
 #define BTN_UP 3
 #define BTN_DOWN 4
 
-static uint32_t audio_samples[SAMPLE_COUNT * 2]; // 2x size needed for complex FFT
+// Y axis scaling factors
-static float *audio_samples_f = (float *) audio_samples;
+#define WAVEFORM_SCALE 0.008f
+#define FFT_SCALE 0.25f * 0.3f
+#define FFT_SPINDLE_SCALE_MULT 0.5f
+
+uint32_t audio_samples[SAMPLE_COUNT * 2]; // 2x size needed for complex FFT
+float *audio_samples_f = (float *) audio_samples;
+
+/** Dot matrix display instance */
+DotMatrix_Cfg *disp;
+
+/** Capture in progress flag */
+volatile bool capture_pending = false;
 
-static DotMatrix_Cfg *disp;
+/** scale & brightness config fields. Initial values. */
+float y_scale = 3;
+uint8_t brightness = 4;
 
-static volatile bool capture_pending = false;
+/** active rendering mode (visualisation preset) */
+enum {
+	MODE_WAVEFORM = 0,
+	MODE_SPECTRUM = 1,
+	MODE_SPECTRUM2 = 2,
+} render_mode;
 
-static float waveform_scale = 3;
+#define MODE_MAX MODE_SPECTRUM2
+
+bool up_pressed = false;
+bool down_pressed = false;
+bool left_pressed = false;
+bool right_pressed = false;
 
 static void display_wave();
+
+static void calculate_fft();
+
 static void display_fft();
 
+static void display_fft_spindle();
+
+static void start_render();
+
 // region Audio capture & display
 
+/** Start DMA to capture audio */
 void capture_start()
 {
 	if (capture_pending) return;
@@ -56,7 +89,22 @@ void capture_start()
 /** This callback is called by HAL after the transfer is complete */
 void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc)
 {
+	switch (render_mode) {
+		case MODE_WAVEFORM:
 			display_wave();
+			break;
+
+		case MODE_SPECTRUM:
+			calculate_fft();
+			display_fft();
+			break;
+
+		case MODE_SPECTRUM2:
+			calculate_fft();
+			display_fft_spindle();
+			break;
+	}
+
 	capture_pending = false;
 }
 
@@ -93,8 +141,6 @@ void spread_samples_for_fft()
 /** Display waveform preview */
 void display_wave()
 {
-	float wave_y_mult = 0.0078125f;
-
 	samples_to_float();
 
 	int x_offset = 0;
@@ -111,15 +157,18 @@ void display_wave()
 		x_offset = 0;
 	}
 
-	dmtx_clear(disp);
+	float totalmult = WAVEFORM_SCALE * y_scale;
+
+	start_render();
 	for (int i = 0; i < SCREEN_W; i++) {
-		dmtx_set(disp, i, 7 + roundf(audio_samples_f[i + x_offset] * wave_y_mult * waveform_scale), 1);
+		dmtx_set(disp, i, 7 + roundf(audio_samples_f[i + x_offset] * totalmult), 1);
 	}
+
 	dmtx_show(disp);
 }
 
 /** Calculate and display FFT */
-static void display_fft()
+static void calculate_fft()
 {
 	float *bins = audio_samples_f;
 
@@ -127,41 +176,66 @@ static void display_fft()
 	spread_samples_for_fft();
 
 	const arm_cfft_instance_f32 *S;
-	S = &arm_cfft_sR_f32_len128;
+	S = &CFFT_INST;
 
 	arm_cfft_f32(S, bins, 0, true); // bit reversed FFT
 	arm_cmplx_mag_f32(bins, bins, BIN_COUNT); // get magnitude (extract real values)
 
 	// Normalize & display
 
-	dmtx_clear(dmtx);
+	start_render();
 
-	float factor = (1.0f / BIN_COUNT) * 0.25f;
+	float factor = (1.0f / BIN_COUNT) * FFT_SCALE * y_scale;
 	for (int i = 0; i < BIN_COUNT; i++) { // +1 because bin 0 is always 0
 		bins[i] *= factor;
 	}
+}
+
+/** Render classic FFT */
+static void display_fft()
+{
+	float *bins = audio_samples_f;
 
-	// TODO implement offset using gamepad buttons (?)
 	for (int x = 0; x < SCREEN_W; x++) {
 		for (int j = 0; j < 1 + floorf(bins[x]); j++) {
-			dmtx_set(dmtx, x, j, 1);
+			dmtx_set(disp, x, j, 1);
+		}
+	}
+
+	dmtx_show(disp);
+}
+
+/** Render FFT "spindle" */
+static void display_fft_spindle()
+{
+	float *bins = audio_samples_f;
+
+	for (int x = 0; x < SCREEN_W; x++) {
+		for (int j = 0; j < 1 + floorf(bins[x] * FFT_SPINDLE_SCALE_MULT); j++) {
+			dmtx_set(disp, x, 7 + j, 1);
+			dmtx_set(disp, x, 7 - j, 1);
 		}
 	}
 
-	dmtx_show(dmtx);
+	dmtx_show(disp);
 }
 
 // endregion
 
-// Increment timebase counter each ms
+// region UI
-void HAL_SYSTICK_Callback(void)
+
+/** Clear screen & render "HUD" - button feedback lights */
+void start_render()
 {
-	timebase_ms_cb();
+	dmtx_clear(disp);
-}
 
-bool up_pressed = false;
+	if (up_pressed) dmtx_set(disp, SCREEN_W - 2, SCREEN_H - 1, 1);
-bool down_pressed = false;
+	if (down_pressed) dmtx_set(disp, SCREEN_W - 2, SCREEN_H - 3, 1);
+	if (left_pressed) dmtx_set(disp, SCREEN_W - 3, SCREEN_H - 2, 1);
+	if (right_pressed) dmtx_set(disp, SCREEN_W - 1, SCREEN_H - 2, 1);
+}
 
+/** Callback when button press state changes */
 static void gamepad_button_cb(uint32_t btn, bool press)
 {
 	dbg("Button press %d, state %d", btn, press);
@@ -170,13 +244,47 @@ static void gamepad_button_cb(uint32_t btn, bool press)
 		case BTN_UP:
 			up_pressed = press;
 			break;
+
 		case BTN_DOWN:
 			down_pressed = press;
 			break;
+
+		case BTN_LEFT:
+			left_pressed = press;
+			break;
+
+		case BTN_RIGHT:
+			right_pressed = press;
+			break;
+
+		case BTN_CENTER:
+			if (!press) {
+				// center button released
+				// cycle through modes
+				if (render_mode++ == MODE_MAX) {
+					render_mode = 0;
 				}
 			}
 
-void user_init() {
+			info("Switched to render mode %d", render_mode);
+			break;
+	}
+}
+
+// endregion
+
+/**
+ * Increment timebase counter each ms.
+ * This is called by HAL, weak override.
+ */
+void HAL_SYSTICK_Callback(void)
+{
+	timebase_ms_cb();
+}
+
+/** Init the application */
+void user_init()
+{
 	// Enable audio input
 	HAL_GPIO_WritePin(AUDIO_NSTBY_GPIO_Port, AUDIO_NSTBY_Pin, 1);
 
@@ -189,7 +297,7 @@ void user_init() {
 	disp_init.SPIx = SPI1;
 	disp = dmtx_init(&disp_init);
 
-	dmtx_intensity(disp, 7);
+	dmtx_intensity(disp, brightness);
 
 	dmtx_clear(disp);
 	dmtx_show(disp);
@@ -229,7 +337,7 @@ void user_init() {
 	debo_register_pin(&debo);
 }
 
-
+/** Main function, called from MX-generated main.c */
 void user_main()
 {
 	banner("== USER CODE STARTING ==");
@@ -237,30 +345,53 @@ void user_main()
 	user_init();
 
 	ms_time_t counter1 = 0;
-	uint32_t counter2 = 0;
+	ms_time_t counter2 = 0;
-	uint32_t btn_scale_cnt = 0;
+	ms_time_t btn_scale_cnt = 0;
+	ms_time_t btn_brt_cnt = 0;
 	while (1) {
 		if (ms_loop_elapsed(&counter1, 500)) {
 			// Blink
 			HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
 		}
 
+		// hold-to-repeat for up/down buttons (sensitivity)
+		// This is not the correct way to do it, but good enough
 		if (ms_loop_elapsed(&btn_scale_cnt, 50)) {
 			if (up_pressed) {
-				waveform_scale += 0.1;
+				y_scale += 0.1;
 			}
 
 			if (down_pressed) {
-				if (waveform_scale > 0.1) {
+				if (y_scale > 0.1) {
-					waveform_scale -= 0.1;
+					y_scale -= 0.1;
 				}
 			}
 
 			if (up_pressed || down_pressed) {
-				dbg("scale = %.1f", waveform_scale);
+				dbg("scale = %.1f", y_scale);
+			}
+		}
+
+		// hold-to-repeat for left/right buttons (brightness)
+		if (ms_loop_elapsed(&btn_brt_cnt, 200)) {
+			if (left_pressed) {
+				if (brightness > 0) {
+					brightness--;
+				}
+			}
+
+			if (right_pressed) {
+				if (brightness < 15) {
+					brightness++;
+				}
+			}
+
+			if (left_pressed || right_pressed) {
+				dmtx_intensity(disp, brightness);
 			}
 		}
 
+		// capture a sample to update display
 		if (!capture_pending) {
 			capture_start();
 		}
@@ -269,6 +400,7 @@ void user_main()
 
 //region Error handlers
 
+/** Called from MX-generated HAL error handler */
 void user_Error_Handler()
 {
 	error("HAL error occurred.\n");