├── .cproject
├── .project
├── CMakeLists.txt
├── README.md
└── main
    ├── CMakeLists.txt
    ├── Kconfig.projbuild
    └── main.c


/.cproject:
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 1 | <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 2 | <?fileVersion 4.0.0?><cproject storage_type_id="org.eclipse.cdt.core.XmlProjectDescriptionStorage">
 3 | 	<storageModule moduleId="org.eclipse.cdt.core.settings">
 4 | 		<cconfiguration id="org.eclipse.cdt.core.default.config.352675087">
 5 | 			<storageModule buildSystemId="org.eclipse.cdt.core.defaultConfigDataProvider" id="org.eclipse.cdt.core.default.config.352675087" moduleId="org.eclipse.cdt.core.settings" name="Configuration">
 6 | 				<externalSettings/>
 7 | 				<extensions/>
 8 | 			</storageModule>
 9 | 			<storageModule moduleId="org.eclipse.cdt.core.externalSettings"/>
10 | 		</cconfiguration>
11 | 	</storageModule>
12 | 	<storageModule moduleId="org.eclipse.cdt.core.pathentry">
13 | 		<pathentry kind="src" path=""/>
14 | 		<pathentry excluding="**/CMakeFiles/**" kind="out" path="build"/>
15 | 	</storageModule>
16 | 	<storageModule moduleId="org.eclipse.cdt.core.LanguageSettingsProviders"/>
17 | </cproject>
18 | 


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/.project:
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 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <projectDescription>
 3 | 	<name>ESP32_Scope1</name>
 4 | 	<comment></comment>
 5 | 	<projects>
 6 | 	</projects>
 7 | 	<buildSpec>
 8 | 		<buildCommand>
 9 | 			<name>org.eclipse.cdt.core.cBuilder</name>
10 | 			<triggers>clean,full,incremental,</triggers>
11 | 			<arguments>
12 | 			</arguments>
13 | 		</buildCommand>
14 | 	</buildSpec>
15 | 	<natures>
16 | 		<nature>org.eclipse.cdt.core.cnature</nature>
17 | 		<nature>org.eclipse.cdt.core.ccnature</nature>
18 | 		<nature>com.espressif.idf.core.idfNature</nature>
19 | 	</natures>
20 | </projectDescription>
21 | 


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/CMakeLists.txt:
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1 | # The following lines of boilerplate have to be in your project's
2 | # CMakeLists in this exact order for cmake to work correctly
3 | cmake_minimum_required(VERSION 3.5)
4 | 
5 | include($ENV{IDF_PATH}/tools/cmake/project.cmake)
6 | project(app-template)
7 | 


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/README.md:
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 1 | ESP32 Sampling audio using I2S ADC and piping it to a remote PC via UDP
 2 | ========================
 3 | The demo samples audio using I2S. The sampled buffer is then transmitted to a PC via UDP socket. The audio is then played using aplay utility.
 4 | 
 5 | ### Hardware Required
 6 | This example is able to run on any commonly available ESP32 development board. The ADC input should be connected to ADC1 Channel 0 pin. 
 7 | 
 8 | ### Wireless Configuration
 9 | Setup your wireless SSID and password in sdkconfig file, via menuconfig, or use esp_wifi_set_config() API.
10 | 
11 | ### PC Configuration
12 | Make sure alsa is installed. If not, please install alsa package first:  
13 |   
14 | `sudo apt-get install alsa-utils`  
15 |   
16 | Use netcat (nc) to open a UDP port. Then pipe the raw values to aplay as shown below:  
17 |   
18 | `nc -ul 7777 | aplay -r 16000 -f S16_BE`  
19 | 
20 | 
21 | 


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/main/CMakeLists.txt:
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1 | # Edit following two lines to set component requirements (see docs)
2 | set(COMPONENT_REQUIRES )
3 | set(COMPONENT_PRIV_REQUIRES )
4 | 
5 | set(COMPONENT_SRCS "main.c")
6 | set(COMPONENT_ADD_INCLUDEDIRS "")
7 | 
8 | register_component()
9 | 


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/main/Kconfig.projbuild:
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 1 | # put here your custom config value
 2 | menu "Example Configuration"
 3 | config ESP_WIFI_SSID
 4 |     string "WiFi SSID"
 5 |     default "myssid"
 6 |     help
 7 | 	SSID (network name) for the example to connect to.
 8 | 
 9 | config ESP_WIFI_PASSWORD
10 |     string "WiFi Password"
11 |     default "mypassword"
12 |     help
13 | 	WiFi password (WPA or WPA2) for the example to use.
14 | endmenu
15 | 


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/main/main.c:
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  1 | /*   example:
  2 |  *   nc -ul 7777 | aplay -r 16000 -f S16_BE
  3 |  *
  4 |  */
  5 | 
  6 | 
  7 | #include "freertos/FreeRTOS.h"
  8 | #include "esp_wifi.h"
  9 | #include "esp_system.h"
 10 | #include "esp_event.h"
 11 | #include "esp_event_loop.h"
 12 | #include "nvs_flash.h"
 13 | #include "driver/gpio.h"
 14 | 
 15 | #include "driver/gpio.h"
 16 | #include "driver/adc.h"
 17 | #include "driver/timer.h"
 18 | #include <soc/sens_reg.h>
 19 | #include <soc/sens_struct.h>
 20 | #include "lwip/err.h"
 21 | #include "lwip/sockets.h"
 22 | #include "lwip/sys.h"
 23 | #include <lwip/netdb.h>
 24 | #include "esp_log.h"
 25 | #include "driver/i2s.h"
 26 | 
 27 | // local setup
 28 | #define ADC_SAMPLES_COUNT 512
 29 | #define SAMPLE_RATE  16000
 30 | #define HOST_IP_ADDR "192.168.86.31"
 31 | #define HOST_PORT 7777
 32 | 
 33 | #define I2S_SAMPLE_RATE 44100
 34 | #define I2S_BUFFER 512
 35 | 
 36 | // ADC buffer
 37 | uint8_t abuf[ADC_SAMPLES_COUNT];
 38 | uint8_t abuf_tx[ADC_SAMPLES_COUNT];
 39 | int16_t abufPos = 0;
 40 | 
 41 | // timer stuff
 42 | static intr_handle_t s_timer_handle;
 43 | portMUX_TYPE DRAM_ATTR timerMux = portMUX_INITIALIZER_UNLOCKED;
 44 | 
 45 | // RTOS stuff
 46 | TaskHandle_t udp_task_handle;
 47 | TaskHandle_t i2s_task_handle;
 48 | 
 49 | // debug tag
 50 | static const char *TAG = "Scope1:";
 51 | int wifi_init = false;
 52 | 
 53 | 
 54 | 
 55 | //----------------------------------------------------------------------------------------//
 56 | // I2S setup for ADC sampling
 57 | //----------------------------------------------------------------------------------------//
 58 | void init_i2s()
 59 | {
 60 | 	// configure I2S
 61 | 	i2s_config_t i2s_config;
 62 | 	i2s_config.mode = I2S_MODE_MASTER | I2S_MODE_RX | I2S_MODE_ADC_BUILT_IN;
 63 | 	i2s_config.sample_rate = I2S_SAMPLE_RATE;
 64 | 	i2s_config.dma_buf_len = I2S_BUFFER;
 65 | 	i2s_config.bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT;
 66 | 	//i2s_config.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT;
 67 | 	i2s_config.channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT;
 68 | 	i2s_config.use_apll = false,
 69 | 	i2s_config.communication_format = I2S_COMM_FORMAT_PCM;
 70 | 	i2s_config.intr_alloc_flags = 0;
 71 | 	i2s_config.dma_buf_count = 5;
 72 | 
 73 | 	// install and start i2s driver
 74 | 	ESP_ERROR_CHECK( adc_gpio_init(ADC_UNIT_1, ADC_CHANNEL_0) );
 75 | 	ESP_ERROR_CHECK( i2s_driver_install(I2S_NUM_0, &i2s_config,  0, NULL) );
 76 | 	ESP_ERROR_CHECK( i2s_set_adc_mode(ADC_UNIT_1, ADC1_CHANNEL_0) );
 77 | 
 78 | 	//vTaskDelay(5000 / portTICK_RATE_MS);
 79 | 	//printf("Done waiting, enable ADC... \n");
 80 | 
 81 | 	ESP_ERROR_CHECK( i2s_adc_enable(I2S_NUM_0) );
 82 | }
 83 | 
 84 | 
 85 | void disp_buf(uint8_t* buf, int length)
 86 | {
 87 |     printf("======\n");
 88 |     for (int i = 0; i < length; i++) {
 89 |         printf("%02x ", buf[i]);
 90 |         if ((i + 1) % 16 == 0) {
 91 |             printf("\n");
 92 |         }
 93 |     }
 94 |     printf("======\n");
 95 | }
 96 | 
 97 | 
 98 | //----------------------------------------------------------------------------------------//
 99 | // ADC sampling through I2S
100 | //----------------------------------------------------------------------------------------//
101 | void sample_i2s()
102 | {
103 | 	ESP_LOGI(TAG, "Task called.");
104 | 	//uint16_t i2s_buff[I2S_BUFFER];
105 | 	int i2s_read_len = I2S_BUFFER;
106 | 	char* i2s_buff = (char*) calloc(i2s_read_len, sizeof(char));
107 | 
108 | 	// send UDP data
109 | 	int addr_family = 0;
110 | 	int ip_protocol = 0;
111 | 	char host_ip[] = HOST_IP_ADDR;
112 | 
113 | 	struct sockaddr_in dest_addr;
114 | 	dest_addr.sin_addr.s_addr = inet_addr(HOST_IP_ADDR);
115 | 	dest_addr.sin_family = AF_INET;
116 | 	dest_addr.sin_port = htons(HOST_PORT);
117 | 	addr_family = AF_INET;
118 | 	ip_protocol = IPPROTO_IP;
119 | 	int sock = -1;
120 | 	sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
121 | 	if (sock < 0) {
122 | 		ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
123 | 	}
124 | 	ESP_LOGI(TAG, "Socket created, sending to %s:%d", HOST_IP_ADDR, HOST_PORT);
125 | 
126 | 
127 | 	while (true) {
128 | 
129 | 		size_t bytes_read = 0;
130 | 		//ESP_ERROR_CHECK( i2s_adc_enable(I2S_NUM_0) );
131 | 
132 | 		//ESP_LOGI(TAG, "before call.");
133 | 		ESP_ERROR_CHECK( i2s_read(I2S_NUM_0, (void*) i2s_buff, i2s_read_len, &bytes_read, portMAX_DELAY) );
134 | 		//ESP_LOGI(TAG, "after call.");
135 | 
136 | 		//ESP_LOGI(TAG,"I2s bytes read: %d", bytes_read);
137 | 
138 | 		if (bytes_read == 0)
139 | 			continue;
140 | 
141 | 		//vTaskDelay(10 / portTICK_RATE_MS);
142 | 
143 | 		memcpy(abuf_tx, i2s_buff, bytes_read);
144 | 
145 | //		// convert to bytes
146 | //		for (int i=0; i < bytes_read; i++) {
147 | //			abuf_tx[abufPos++] = (i2s_buff[i] >> 8) & 0xFF;
148 | //			abuf_tx[abufPos++] = i2s_buff[i] & 0xFF;
149 | //		}
150 | 
151 | //		// notify ADC task that the buffer is full
152 | //		BaseType_t xHigherPriorityTaskWoken = pdFALSE;
153 | //		vTaskNotifyGiveFromISR(udp_task_handle, &xHigherPriorityTaskWoken);
154 | //		if (xHigherPriorityTaskWoken) {
155 | //		  portYIELD_FROM_ISR();
156 | //		}
157 | 
158 | 		// send UDP payload
159 | 		int err = sendto(sock, (const uint8_t *)abuf_tx, ADC_SAMPLES_COUNT, 0, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
160 | 		if (err < 0)
161 | 		{
162 | 			ESP_LOGE(TAG, "Error occurred during sending: errno %d", errno);
163 | 		}
164 | 	}
165 | 
166 | 	shutdown(sock, 0);
167 | 	close(sock);
168 | }
169 | 
170 | //----------------------------------------------------------------------------------------//
171 | // ADC setup
172 | //----------------------------------------------------------------------------------------//
173 | void init_adc( void )
174 | {
175 | 	adc1_config_width(ADC_WIDTH_BIT_12);
176 | 	adc1_config_channel_atten(ADC1_CHANNEL_0, ADC_ATTEN_DB_0);
177 | }
178 | 
179 | 
180 | //----------------------------------------------------------------------------------------//
181 | // timer setup
182 | //----------------------------------------------------------------------------------------//
183 | static void timer_isr(void* arg)
184 | {
185 | 	portENTER_CRITICAL_ISR(&timerMux);
186 |     TIMERG0.int_clr_timers.t0 = 1;
187 |     TIMERG0.hw_timer[0].config.alarm_en = 1;
188 | 
189 |     // read ADC
190 |     uint16_t adc_value = adc1_get_raw(ADC1_CHANNEL_0);
191 | 
192 |     // convert to bytes
193 |     abuf[abufPos++] = (adc_value >> 8) & 0xFF;
194 |     abuf[abufPos++] = adc_value & 0xFF;
195 | 
196 |     // copy buffer into a second buffer for transmission
197 |     if (abufPos >= ADC_SAMPLES_COUNT) {
198 |         abufPos = 0;
199 | 	    memcpy(abuf_tx, abuf, ADC_SAMPLES_COUNT);
200 | 
201 |         // notify ADC task that the buffer is full
202 |         BaseType_t xHigherPriorityTaskWoken = pdFALSE;
203 |         vTaskNotifyGiveFromISR(udp_task_handle, &xHigherPriorityTaskWoken);
204 |         if (xHigherPriorityTaskWoken) {
205 |           portYIELD_FROM_ISR();
206 |         }
207 |     }
208 | 
209 | 	portEXIT_CRITICAL_ISR(&timerMux);
210 | }
211 | 
212 | 
213 | //----------------------------------------------------------------------------------------//
214 | // init timer
215 | //----------------------------------------------------------------------------------------//
216 | void init_timer(int timer_period_us)
217 | {
218 |     timer_config_t config = {
219 |             .alarm_en = true,
220 |             .counter_en = false,
221 |             .intr_type = TIMER_INTR_LEVEL,
222 |             .counter_dir = TIMER_COUNT_UP,
223 |             .auto_reload = true,
224 |             .divider = 80   /* 1 us per tick */
225 |     };
226 | 
227 |     timer_init(TIMER_GROUP_0, TIMER_0, &config);
228 |     timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
229 |     timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, timer_period_us);
230 |     timer_enable_intr(TIMER_GROUP_0, TIMER_0);
231 |     timer_isr_register(TIMER_GROUP_0, TIMER_0, &timer_isr, NULL, 0, &s_timer_handle);
232 |     timer_start(TIMER_GROUP_0, TIMER_0);
233 | }
234 | 
235 | 
236 | //----------------------------------------------------------------------------------------//
237 | // send UDP data
238 | //----------------------------------------------------------------------------------------//
239 | void udp_task(void *param) {
240 | 	int addr_family = 0;
241 | 	int ip_protocol = 0;
242 | 	char host_ip[] = HOST_IP_ADDR;
243 | 
244 | 	struct sockaddr_in dest_addr;
245 | 	dest_addr.sin_addr.s_addr = inet_addr(HOST_IP_ADDR);
246 | 	dest_addr.sin_family = AF_INET;
247 | 	dest_addr.sin_port = htons(HOST_PORT);
248 | 	addr_family = AF_INET;
249 | 	ip_protocol = IPPROTO_IP;
250 | 	int sock = -1;
251 | 	while (sock < 0) {
252 | 		sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
253 | 		if (sock < 0)
254 | 			ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
255 | 	}
256 | 	ESP_LOGI(TAG, "Socket created, sending to %s:%d", HOST_IP_ADDR, HOST_PORT);
257 | 	while (true) {
258 | 		// sleep until the ISR gives us something to do
259 | 		uint32_t tcount = ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
260 | 
261 | //	    for (int i = 0; i < 10; i++) {
262 | //	    	ESP_LOGI(TAG, "ADC value: %d", abuf_tx[i]);
263 | //	    }
264 | 
265 | 		// send UDP payload
266 | 		ESP_LOGI(TAG, "UDPTask got called.");
267 | 		int err = sendto(sock, (const uint8_t *)abuf_tx, ADC_SAMPLES_COUNT, 0, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
268 | 		if (err < 0)
269 | 		{
270 | 			ESP_LOGE(TAG, "Error occurred during sending: errno %d", errno);
271 | 			ESP_LOGI(TAG, "Closing socket. Trying again...");
272 | 			close(sock);
273 | 			sock = -1;
274 | 			while (sock < 0) {
275 | 				sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
276 | 				if (sock < 0)
277 | 					ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
278 | 			}
279 | 			ESP_LOGI(TAG, "Connected again.");
280 | 		}
281 | 		else
282 | 			ESP_LOGI(TAG, "Packet sent.");
283 | 	}
284 | 	shutdown(sock, 0);
285 | 	close(sock);
286 | }
287 | 
288 | 
289 | //----------------------------------------------------------------------------------------//
290 | // UDP client socket
291 | //----------------------------------------------------------------------------------------//
292 | void init_socket(void){
293 | 	struct sockaddr_in dest_addr;
294 |     dest_addr.sin_addr.s_addr = inet_addr(HOST_IP_ADDR);
295 |     dest_addr.sin_family = AF_INET;
296 |     dest_addr.sin_port = htons(HOST_PORT);
297 |     int addr_family = AF_INET;
298 |     int ip_protocol = IPPROTO_IP;
299 | 
300 |     // connect to UDF server
301 |     while (1) {
302 | 		int sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
303 | 		if (sock < 0) {
304 | 			ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
305 | 		}
306 | 		ESP_LOGI(TAG, "Socket created, sending to %s:%d", HOST_IP_ADDR, HOST_PORT);
307 | 		break;
308 |     }
309 | }
310 | 
311 | 
312 | //----------------------------------------------------------------------------------------//
313 | // event handler
314 | //----------------------------------------------------------------------------------------//
315 | esp_err_t event_handler(void *ctx, system_event_t *event)
316 | {
317 |     switch(event->event_id) {
318 |     case SYSTEM_EVENT_STA_START:
319 | 		esp_wifi_connect();
320 | 		ESP_LOGI(TAG,"Disconnected! Trying to connect to WiFi network...");
321 | 		break;
322 |     case SYSTEM_EVENT_STA_GOT_IP:
323 | 		ESP_LOGI(TAG, "Received assigned IP Address:%s",
324 | 				 ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
325 | 		if (!wifi_init) {
326 | 			wifi_init = true;
327 | 
328 | 			// init timer TBD <<< enable again
329 | 			//float calls = (float)1/(float)SAMPLE_RATE * 1000000;
330 | 			//ESP_LOGI(TAG, "Timer is set to: %f", calls);
331 | 			//init_timer(calls);
332 | 		}
333 | 	    break;
334 |     case SYSTEM_EVENT_STA_DISCONNECTED:
335 | 		esp_wifi_connect();
336 | 		ESP_LOGI(TAG,"Disconnected! Trying to connect to WiFi network...");
337 | 		break;
338 |     default:
339 |         break;
340 |     }
341 |     return ESP_OK;
342 | }
343 | 
344 | 
345 | //----------------------------------------------------------------------------------------//
346 | // init wifi connection
347 | //----------------------------------------------------------------------------------------//
348 | void init_wifi(void)
349 | {
350 |     nvs_flash_init();
351 |     tcpip_adapter_init();
352 |     ESP_ERROR_CHECK(esp_event_loop_create_default());
353 |     ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) );
354 |     wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
355 |     ESP_ERROR_CHECK( esp_wifi_init(&cfg) );
356 |     ESP_ERROR_CHECK( esp_wifi_set_storage(WIFI_STORAGE_RAM) );
357 |     ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );
358 |     wifi_config_t sta_config = {
359 |         .sta = {
360 |             .ssid = CONFIG_ESP_WIFI_SSID,
361 |             .password = CONFIG_ESP_WIFI_PASSWORD,
362 |             .bssid_set = false
363 |         }
364 |     };
365 |     ESP_ERROR_CHECK( esp_wifi_set_config(WIFI_IF_STA, &sta_config) );
366 |     ESP_ERROR_CHECK( esp_wifi_start() );
367 |     ESP_ERROR_CHECK( esp_wifi_connect() );
368 | 
369 |     // wait until IP is assigned
370 |     ESP_LOGI(TAG,"Waiting for IP address...");
371 |     while (!wifi_init) {
372 |     	vTaskDelay(100 / portTICK_RATE_MS);
373 |     }
374 | 
375 | }
376 | 
377 | 
378 | //----------------------------------------------------------------------------------------//
379 | // main app logic
380 | //----------------------------------------------------------------------------------------//
381 | void app_main(void)
382 | {
383 | 	// init wifi
384 | 	init_wifi();
385 | 
386 |     // init ADC
387 |     init_adc();
388 | 
389 | 	// init I2S
390 | 	init_i2s();
391 | 
392 | 	// UDP caller task
393 | 	//xTaskCreate(udp_task, "UDP Client Task", 8192, NULL, 5, &udp_task_handle);
394 | 
395 | 	// I2S sampler task
396 | 	xTaskCreate(sample_i2s, "I2S Task", 8192, NULL, 5, &i2s_task_handle);
397 | }
398 | 
399 | 


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