ESP32-based Feather Breakout and Development Board

ESP32-based Enhanced Feather Dev Board WiFi+Bluetooth with Onboard LiPo Charger, CP2104 USB to Serial. Arduino Programmable.

The ESP32 Feather board is an enhanced clone of the ESP32 Feather board made by Adafruit.  The pinout is identical to the other ESP32 Feather module with the exception of the Enable pin.  This module does not include the enable function.  The Deep Sleep current draw from the cell is below 10uA.  Other than the ESP32E module it has an Si Labs CP2104USB to Serial converter, A 3.3V LDO, Reset switch and an LED.

https://news.ezsbc.com/esp32-in-feather-format/

The Cell voltage divider does not discharge the LiPo cell when it it not in use.  The divider is only enabled when the cell voltage is sensed and can then be disabled to save an extra 20uA of current drain from the cell.

The board uses the latest ESP32-WROOM-32E module .

The Deep Sleep current is less than 10uA from the cell.

There are two LEDs on the board, the red and green LEDs hooked up to the CP2104 to signal transmit and receive activity and is powered from the USB connector.

The board supports auto-download from the Arduino environment and will automatically be set in download mode by the downloader. Once the download is complete the board will be reset, just like a normal Arduino board.

All the required capacitors and pull-up resistors are fitted on the board. The board can be powered from an external power supply of up to 6V or the USB connector or both.

When external power is present the cell is charged with a 400mA charge current to a 4.2V cutoff voltage.

When the external power is present and the cell discharges the cell will automatically be re-charged.

Boards purchased without a cell will receive the matching charge cable.

The Cell connector is a JST2R commonly used on LiPo cells.

The module can be programmed directly from the Arduino environment without pushing any buttons. The upload speed is 921600 bps.

The module has been designed to be used in Sleep mode without excessive current draw.  I read 12uA when powering from the Vin and Gnd pins with the processor in deep sleep mode.

The overall dimensions and pinout is identical to the ESP32-Feather board.

The schematic and example code is on Github.

• 240 MHz dual core Tensilica LX6 microcontroller with 600 DMIPS
• Integrated 520 KB SRAM
• Integrated 802.11BGN HT40 Wi-Fi transceiver, baseband, stack and LWIP
• Integrated dual mode Bluetooth (classic and BLE)
• 4 MByte flash
• On-board PCB antenna
• 3 x UARTs, including hardware flow control
• 3 x SPI
• 2 x I2S
• 12 x ADC input channels
• 2 x DAC
• 2 x I2C
• PWM/timer input/output available on every GPIO pin
• SDIO master/slave 50 MHz
• Supports external SPI flash up to 16 MB
• SD-card interface support
• 2.2V to 3.6V operating voltage  3.6V to 5.5V on Vin, 3.0V to 3.6V driving the 3.3V pin directly.