こんにちは
今回はESP32のモジュールにあるPSRAMの使い方を書いてみたいと思います。
JSONや大量のデータをWEBやアプリから受信して、使うことがありました。
使ったモジュール
PSRAMは
-
ESP32-WROVER-B
-
ESP32-WROVER-I
しかいないので、確認してみてください。
PSRAMの設定
- 簡単です。
- Arduino IDEでTools > PSRAM > DisableをEnabledに変える
- ESP32 Wrover Moduleを持って使っている方はComplieのとき、DefaultでPSRAMを使うことができます。
例1
main.ino
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
//PSRAM Initialisation
if (psramInit()) {
Serial.println("\nThe PSRAM is correctly initialized");
} else {
Serial.println("\nPSRAM does not work");
}
log_d("Total heap: %d", ESP.getHeapSize());
log_d("Free heap: %d", ESP.getFreeHeap());
log_d("Total PSRAM: %d", ESP.getPsramSize());
log_d("Free PSRAM: %d", ESP.getFreePsram());
}
void loop() {
// put your main code here, to run repeatedly:
}
例1の結果
16:17:58.266 -> rst:0x10 (RTCWDT_RTC_RESET),boot:0x17 (SPI_FAST_FLASH_BOOT)
16:17:58.266 -> configsip: 0, SPIWP:0xee
16:17:58.266 -> clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
16:17:58.266 -> mode:DIO, clock div:1
16:17:58.266 -> load:0x3fff0030,len:1252
16:17:58.266 -> load:0x40078000,len:12716
16:17:58.266 -> load:0x40080400,len:3068
16:17:58.266 -> entry 0x400805e4
16:17:58.403 ->
16:17:59.264 -> The PSRAM is correctly initialized
16:17:59.264 -> [ 881][D][sketch_apr10a.ino:11] setup(): Total heap: 394571
16:17:59.264 -> [ 882][D][sketch_apr10a.ino:12] setup(): Free heap: 335479
16:17:59.264 -> [ 884][D][sketch_apr10a.ino:13] setup(): Total PSRAM: 4192139
16:17:59.264 -> [ 889][D][sketch_apr10a.ino:14] setup(): Free PSRAM: 4192139
getPsramSize()
uint32_t EspClass::getPsramSize(void)
{
multi_heap_info_t info;
heap_caps_get_info(&info, MALLOC_CAP_SPIRAM);
return info.total_free_bytes + info.total_allocated_bytes;
}
psramInit()
- https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/esp32-hal-psram.c
- https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/esp32-hal-psram.h
例2
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
//PSRAM Initialisation
if (psramInit()) {
Serial.println("\nThe PSRAM is correctly initialized");
} else {
Serial.println("\nPSRAM does not work");
}
log_d("Total heap: %d", ESP.getHeapSize());
log_d("Free heap: %d", ESP.getFreeHeap());
log_d("Total PSRAM: %d", ESP.getPsramSize());
log_d("Free PSRAM: %d", ESP.getFreePsram());
//Create an integer
int *var_int = (int *) ps_malloc(sizeof(int));
*var_int = 42;
log_d("var_int PSRAM: %d", ESP.getPsramSize());
log_d("var_int PSRAM: %d", ESP.getFreePsram());
//Create a float
float *var_float = (float *) ps_malloc(sizeof(float));
*var_float = 42.42;
log_d("var_float PSRAM: %d", ESP.getPsramSize());
log_d("var_float PSRAM: %d", ESP.getFreePsram());
Serial.println((String)"var_int = " + *var_int);
Serial.print("var_float = ");
Serial.println(*var_float);
}
void loop() {
// put your main code here, to run repeatedly:
}
例２の結果
16:33:16.824 -> The PSRAM is correctly initialized
16:33:16.824 -> [ 881][D][sketch_apr10a.ino:11] setup(): Total heap: 394571
16:33:16.824 -> [ 882][D][sketch_apr10a.ino:12] setup(): Free heap: 335479
16:33:16.824 -> [ 884][D][sketch_apr10a.ino:13] setup(): Total PSRAM: 4192139
16:33:16.824 -> [ 889][D][sketch_apr10a.ino:14] setup(): Free PSRAM: 4192139
16:33:16.824 -> [ 895][D][sketch_apr10a.ino:19] setup(): var_int PSRAM: 4192127
16:33:16.824 -> [ 901][D][sketch_apr10a.ino:20] setup(): var_int PSRAM: 4192123
16:33:16.869 -> [ 907][D][sketch_apr10a.ino:26] setup(): var_float PSRAM: 4192115
16:33:16.869 -> [ 913][D][sketch_apr10a.ino:27] setup(): var_float PSRAM: 4192107
16:33:16.869 -> var_int = 42
16:33:16.869 -> var_float = 42.42
参考
- https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/external-ram.html
- https://github.com/TridentTD/arduino_esp32_himem
おわりに
- あと、続きます。