Espressif Systems ESP Faq page 171

Chapter 5. Hardware related
• For detailed differences between chip revisions, please refer to respective chip errata documents from Espressif'
s documentation page.
• For a complete explanation of the chip silk marking, please refer to
5.2 Development board
5.2.1 How long does it take for the ESP-WROOM-02D module to restart after the reset
signal?
• It will restart when the input level is lower than 0.6 V for more than 200 μs.
5.2.2 According to the schematic of ESP32-LyraT-Mini, the analog output of the ES8311
codec chip is connected to the input of the ES7243 ADC chip. What is the purpose
of this?
• The hardware acquisition circuit of the AEC reference signal simultaneously transmits the DAC output of the
Codec (ES8311) to the speaker PA and the ADC (ES7243) AINLP/N, of which the signal collected would be
send back to the ESP32 as the reference signal for the AEC algorithm.
5.2.3 When using the ESP32-MINI-1 module, the serial port printed the follows log when
powered on. What could be the reason?
rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
ets Jul 29 2019 12:21:46
• The reason could be flash is not programmed.
Which GPIO is connected to the RGB LED of the
—————————————————————————————————————————————————————
• The RGB LED on the
• The RGB LED on the
• The reason why the ESP32-S3-DevKitC-1 v1.1
is that the ESP32-S3R8V
GPIO47 and GPIO48 in the VDD_SPI power domain of this chip also operate at 1.8 V.
Espressif Systems
ESP32-S3-DevKitC-1 v1.0 development board is connected to GPIO48.
ESP32-S3-DevKitC-1 v1.1 development board is connected to GPIO38.
development board changed the RGB LED pin to GPIO38
chip's VDD_SPI voltage has been set to 1.8 V. Therefore, unlike other GPIOs,
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ESP32-S3-DevKitC-1 development board?
Information.
Release master