ESP32 V3 Deep Sleep

#1

I’m struggling to find a deep sleep example for the new ESP 32 V3. Does any one have one that archives a deep sleep of 10ua?

#2

if any one elese is having problems getting the V3 into deep sleep I hope this helps. I used this example to achive 10ua

void VextOFF(void) //Vext default OFF
{
pinMode(Vext,OUTPUT);
digitalWrite(Vext, HIGH);
}
VextOFF();
Radio.Sleep();
SPI.end();
pinMode(RADIO_DIO_1,ANALOG);
pinMode(RADIO_NSS,ANALOG);
pinMode(RADIO_RESET,ANALOG);
pinMode(RADIO_BUSY,ANALOG);
pinMode(LORA_CLK,ANALOG);
pinMode(LORA_MISO,ANALOG);
pinMode(LORA_MOSI,ANALOG);
esp_sleep_enable_timer_wakeup(6001000(uint64_t)1000);
esp_deep_sleep_start();

#3

Which device did you use? The Wireless Stick Lite (V3)? Your sample code seems very similar (same?) From its Factory test. I was able to get the WSL V3 down to 13uA.

#4

I published a solution here:
https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series/issues/6#issuecomment-1482825342

#5

Make sure you power the device with 3.3v.The difference in current draw during deep sleep when powering the Heltec V3 at 4.2V versus 3.3V can be attributed to the behavior of the voltage regulation and power management circuitry on the board. Here’s why this happens:

1. Voltage Regulation Efficiency :

  • Internal LDO Regulator : The Heltec V3 uses a Low Dropout (LDO) regulator to convert higher input voltages to 3.3V, which is the operational voltage for the ESP32 microcontroller and other components. When you supply 4.2V, the LDO regulator must drop the voltage down to 3.3V.
  • Power Dissipation : LDO regulators work by dissipating excess voltage as heat. When you power the board with 4.2V, the regulator needs to drop 0.9V (from 4.2V to 3.3V), leading to greater power dissipation compared to when the input voltage is closer to 3.3V. This extra dissipation results in higher current draw.

2. Internal Power Consumption Differences :

  • Voltage Differences and Quiescent Current : Components like the LDO regulator itself have a quiescent current — the minimum amount of current required for them to operate. At a higher input voltage (4.2V), the quiescent current can be slightly higher, which contributes to a higher overall current draw.
  • Higher Voltage Operation : When the board is powered at 4.2V, certain internal circuits and protection mechanisms might still be active or in a different operational state compared to when powered at 3.3V. These can consume additional current.

3. Powering Components :

  • Peripheral States : Some peripherals or components on the board might remain partially powered or active when the input voltage is above 3.3V, even during deep sleep, contributing to higher power consumption.

Summary:

  • 3.3V Supply : Provides lower current draw (10 µA) because the input voltage matches the required operating voltage, minimizing power dissipation through the LDO regulator.
  • 4.2V Supply : Leads to higher current draw (24 µA) due to additional power dissipation by the LDO regulator and possible differences in internal component states or quiescent currents.

For low-power applications, supplying a voltage closer to the operating voltage (3.3V in this case) is more efficient and results in lower power consumption, especially in deep sleep modes.

#6

Please read this hardware solution for at least one of your points: