NimBLE ESP32S3 Modem Sleep

[danman009]

Hey all! I'm trying to figure out if it's possible to put my ESP32S3 into a sleep state and have it wake up automatically on a BLE connection. I have migrated from BlueDroid to NimBLE and I see that I have access to the "esp_bt_sleep_enable()" now. My question is if this is possible, and then if anyone know of some small sample code that I can use for inspiration. This is the logic I have:

#include <Arduino.h>
#include <esp_bt.h>
#include <esp_pm.h>

#ifndef LED_BUILTIN
#define LED_BUILTIN 2
#endif

void setup() {
Serial.begin(115200);
Serial.setDebugOutput(true);
pinMode(LED_BUILTIN, OUTPUT);
digitalWrite(LED_BUILTIN, LOW);

// Start up BLE stuff
esp_bt_sleep_enable();
esp_pm_config_esp32s3_t config = {};
config.max_freq_mhz = 240;
config.min_freq_mhz = 80;
config.light_sleep_enable = true;
esp_pm_configure(&config);
BleServer::getInstance().startBleServer(); // custom class that just starts a ble server with a single characteristic exposed
}

void loop() {
delay(10);
}

I'm fairly new to this hobby, but my understanding is that while the server is advertising, as long as the bt sleep and config are set, the modem should automatically enter a light sleep mode on its own. When I manually trigger a light sleep mode via "esp_light_sleep_start()" at the end, my ble server seems to disappear. Am I misunderstanding how things work here?