ESP32 Thing Plus (USB-C) Hookup Guide

Contributors: santaimpersonator, Brudnerd

Hardware Overview

Note: All mentions of GPIO in this section will refer to the I/O pins of the ESP32-WROOM module as represented in the datasheets and pin numbers of the board definition in the ESP32 Arduino core. They do not correspond with the net names for the ThingPlus Form Factor device in the schematic. (The device in the schematic is primarily, used internally to facilitate the board design process; just ignore the naming of the GPIO0 - GPIO6 nets.)

(Click to enlarge)

Board Dimensions

The board dimensions are illustrated in the drawing below. The listed measurements are in inches and the two mounting holes are compatible with 4-40 standoff screws.

Board dimensions (PDF) for the ESP32-WROOM Thing Plus, in inches. (Click to enlarge)

USB-C Connector

The USB connector is provided to power and program the board. For most users, it will be the primary programing interface for the ESP32.

USB-C connector on the ESP32-WROOM Thing Plus. (Click to enlarge)

CH340 Serial-to-UART

The CH340 allows the ESP32-WROOM to communicate with a computer/host device through the board's USB-C connection. This allows the board to show up as a device on the serial (or COM) port of the computer. Users will need to install the latest drivers for the computer to recognize the board (see Software Overview section).

Power

The ESP32-WROOM Thing Plus only requires 3.3V to power the board. However, the simplest method to power the board is through the USB-C connector. Alternatively, the 3V3, VBAT, and VUSB pins can also be used to supply power to the board.

VUSB:
- The maximum voltage for the LDOs and charge controller is 6V.
- The minimum voltage for the charge controller is 3.75V.
VBAT:
- Should not be connected to anything other than a single-cell LiPo battery.
3V3:
- Requires a regulated 3.3V.
- Only powers the board and not the Qwiic connector.

ESP32-WROOM Thing Plus power connections. (Click to enlarge)

Below, is a general summary of the power circuitry on the board:

3V3 - Provides a regulated 3.3V from the USB (5V) power and/or battery connections.
- Used to power the ESP32-WROOM module, µSD card slot, WS2812 RGB LED, CH340C Serial-to-UART bridge, and power LED.
  - The Qwiic connector is powered by its own voltage regulator, from the same power source(s).
- The 3.3V XC6222 LDO regulator can source up to 700mA.
  - Output is controlled by the EN pin on the board.
VUSB - The voltage from the USB-C connector, usually 5V.
- Power source for the entire board.
  - Powers the 3.3V voltage regulators and the battery charging circuit for VBAT.
- Overides power from the battery through a P-channel MOSFET, when both are connected.
- Utilizes a BAT20J protection diode for the USB-C connection.
VBAT - The voltage from the JST battery connector; meant for single cell LiPo batteries.
- Provides power to the 3.3V voltage regulators and MAX17048 battery fuel gauge.
- The MCP73831 linear charge management controller is powered from the USB (5V) power supply.
  - The charge controller is configured for 500mA (max) rate of charge to a connected battery.
GND - The common ground or the 0V reference for the voltage supplies.
Qwiic Connector - Provides a regulated 3.3V voltage from the USB (5V) power and/or battery connections.
- Operates independently from the 3V3 pin, with its own voltage regulator.
- The 3.3V XC6222 LDO regulator can source up to 700mA.
  - Output is controlled by GPIO 0 of the ESP32-WROOM.

For more details, users can reference the schematic and the datasheets of the individual components in the power circuitry.

Power Status LED

The red, PWR LED will light up once 3.3V is supplied to the board; however, for most users, it will light up when 5V is supplied through the USB connection or when a LiPo battery is connected to the JST connector.

ESP32-WROOM Thing Plus PWR status LED indicator. (Click to enlarge)

Charging Circuit

The charging circuit utilizes the MCP73831 linear charge management controller and is powered directly from the USB-C connector or VUSB. The controller is configured for a 500mA charge rate and active charging is indicated by the yellow, CHG LED. If the charge controller is shutdown or charging is complete, the CHG LED will turn off. For more information, please refer to the MCP73831 datasheet and the Indicator LEDs section below.

Power Control

The power source for the XC6222 LDO voltage regulators is controlled by a P-channel MOSFET. In addition, the 3.3V regulated output from the XC6222 LDOs are enabled by the control pin (CE).

Circuits for the 3.3V power on the ESP32-WROOM Thing Plus. (Click to enlarge)

The P-channel MOSFET operates based on the voltages at the MOSFET's gate and source pins. Depending on the power supplies connected to the board, the MOSFET will switch between the battery and USB-C connection as power sources for the XC6222 voltage regulators.

Power Source	MOSFET				Power Control Description
Power Source	Gate	Source	V_GS (V_Gate - V_Source)	MOSFET Operation	Power Control Description
USB Only	V_USB = 5V	V_USB - V_f	V_USB - (V_USB - V_f) V_GS = V_f	MOSFET Off R_GS = ∞ Switch Open	Power to the XC6222 is supplied by the USC-C connection. Power from the USB-C connection is passed through the Schottky diode. Due to the voltage drop from the Schottky diode, the gate threshold voltage for the MOSFET is positive and equivalent to the diode's forward voltage (V_f).Therefore, the MOSFET behaves as an open switch.
Battery Only	V_USB = 0V	Dep. Mode: V_Source = 0 Charged Cap.: V_Batt = 3 - 4.2V	Dep. Mode: V_GS = 0 Charged Cap.: V_USB - V_Batt = -V_Batt -3V > V_GS > -4.2V	MOSFET On R_GS = Low Switch Closed	Power to the XC6222 is supplied from the battery connection. As a depletion type P-channel MOSFET, the mosfet acts as a normally closed switch when the gate threshold voltage is zero. Therefore, power from the battery is able to charge the capacitor and create a negative gate threshold voltage. The MOSFET remains behaving as a closed switch and power to the XC6222 is provided from the battery.
USB & Battery	V_USB = 5V	V_USB - V_f	V_GS = V_f	MOSFET Off R_GS = ∞ Switch Open	Power to the XC6222 is supplied by the USC-C connection. Power from the USB-C connection is passed through the Schottky diode. Due to the voltage drop from the Schottky diode, the gate threshold voltage for the MOSFET is positive and equivalent to the diode's forward voltage (V_f).Therefore, the MOSFET behaves as an open switch.

The control pin (CE) of the XC6222 LDOs also provides an additional amount of control for the board's power. By default, the regulated 3.3V output is enabled. To disable and shutdown the output voltage from the XC6222, the control pin needs to be pulled low (i.e. shorted to ground (GND)). For more information, please refer to the XC6222 datasheet.

The 3.3V power for the board (3V3) is controlled by the EN pin, which is broken out on the board.
The 3.3V power for the Qwiic connector is controlled by GPIO 0 of the ESP32-WROOM.

XC6222 control pins on the ESP32-WROOM Thing Plus. (Click to enlarge)

⚡ Note: The BOOT button is also connected to GPIO 0. Therefore, pressing the BOOT button will momentarily disable power to the Qwiic connector.

Current Consumption

According to the specifications, the ESP32-WROOM draws about 240 mA during RF transmissions. With the WiFi example in this tutorial, have measured it to average around 140 mA and peak at 300 mA while actively transceiving. The table below, summarizes the approximate current draw of the ESP32-WROOM Thing Plus (USB-C) for various operational conditions. The measurements in the table below, were made with the Nordic Power Profiler Kit II.

Operation	Avg. Current Draw
Operation	LiPo: 3.5V (Low < 5%)	LiPo: 3.7V (~15%)	LiPo: 4.2V (~100%)	USB-C: 5V (No Battery)
Idle (Blank Code)	63 mA 86 mA (peak)	63.5 mA 89 mA (peak)	64 mA 88.6 mA (peak)	67 mA 89.9 mA (peak)
Idle: USB + Battery Power (Current from Battery)	--	--	90.5 µA 721 µA (peak)	N/A
Idle: Battery Charging (Current from USB-C)	395 mA 420 mA (peak)	590 mA 600 mA (peak)	> 110 mA (before shutdown)	N/A
RGB (White @ 100%)	78.4 mA 105.9 mA (peak)	79 mA 106.8 mA (peak)	79.9 mA 105.3 mA (peak)	82.5 mA 108.2 mA (peak)
WiFi Example (Transceiving)	135 mA 295 mA (peak)	137 mA 310 mA (peak)	137 mA 307 mA (peak)	140 mA 300 mA (peak)
Deep Sleep Example (MCU Inactive)	2.5 mA 2.95 mA (peak)	2.5 mA 3 mA (peak)	2.55 mA 3 mA (peak)	2.85 mA 3.3 mA (peak)
Deep Sleep Example (MCU Inactive + Jumpers Cut)	842 µA 1.24 mA (peak)	848 µA 1.23 mA (peak)	866 µA 1.24 mA (peak)	1.19 mA 1.58 mA (peak)

It is possible for users to reach sub-mA power consumption levels with the deep sleep power modes. Using the TimerWakeUp Deep Sleep example code, the LED jumpers cut, and powering the board through the LiPo battery connection we measured a power consumption of 845 µA (990 µA peak) @ 3.7V while the MCU was inactive.

The current measurement from VBAT at 3.7V during deep sleep. (Click to enlarge)

ESP32-WROOM

This variant of the ESP32 Thing Plus is designed around the ESP32-WROOM module with 16MB of flash memory. Espressif's ESP32-WROOM module is a versitile, WiFi+BT+BLE MCU module that targets a wide variety of applications. At the core of this module is the ESP32-D0WDQ6 system on a chip (SoC) which is designed to be both scalable and adaptive. Its laundry list of features include:

Xtensa® Dual-Core 32-bit LX6 Microprocessor (up to 240MHz)

448KB ROM and 520KB SRAM
16MB of Embedded SPI Flash Storage

Cryptographic Hardware Accelerators

AES, SHA2, ECC, RSA-4096

Integrated 802.11 b/g/n WiFi 2.4GHz Transceiver (up to 150Mbps)
Integrated dual-mode Bluetooth (Bluetooth v4.2 and BLE)
26 GPIO (including strapping pins)

8x Capacitive Touch Electrodes

Operating Voltage: 3.0 to 3.6V

WiFi: 380mA (peak)
Light-Sleep: 800µA
Deep-Sleep: 10 - 150µA

Note: Users should be aware of the following nuances and details of this board

The ESP32-WROOM is only compatible with 2.4GHz WiFi networks; it will not work on the 5GHz bands.
For details on the boot mode configuration, please refer to section 3.3 Strapping Pins of the ESP32-WROOM module datasheet.

ESP32-WROOM module on the ESP32 Thing Plus (USB-C).
(Click to enlarge)

Note: The ESP32-WROOM module has various power modes:

Active - The chip radio is powered on. The chip can receive, transmit, or listen.
Modem Sleep - The CPU is operational and the clock is configurable. The Wi-Fi/Bluetooth baseband and radio are disabled.
Light Sleep - The CPU is paused. The RTC memory and RTC peripherals, as well as the ULP coprocessor are running.
Deep Sleep - Only the RTC memory and RTC peripherals are powered on. The ULP coprocessor is functional.
Hibernation - Only one RTC timer on the slow clock and certain RTC GPIOs are active.
Off - Chip is powered off

For more information on the power management of the ESP32-WROOM module, pleaser refer to Section 3.7 and Tables: 8 and 17 of the ESP32 SoC Datasheet.

Debugging

For users interested in debugging their code, the JTAG pins are broken out on the board. However, the debugging feature is only available through the ESP-IDF.

TMS: GPIO 14
TDI: GPIO 12
TCK: GPIO 13
TDO: GPIO 15

Note: Users should be aware that GPIO 13 is connected to the STAT LED with a pull down resistor.

Firmware Download Mode

Users can manually force the board into the serial bootloader with the BOOT button. Please, refer to the Boot Button section below for more information.

Peripherals and I/O

Note: Users should be aware of the following nuances of this board

⚡ All the GPIO on the ESP32-WROOM Thing Plus are 3.3V pins.
- The I/O pins are not 5V-tolerant! To interface with higher voltage components, a logic level adapter is recommended.
⚡ There are electrical limitations to the amount of current that the ESP32-WROOM module can sink or source. For more details, check out the ESP32-WROOM module datasheet.
There are some limitations to the ADC performance, see the Note from the ADC Characteristics section of the ESP32 SoC datasheet.

The ESP32-WROOM module has 26 multifunctional GPIO, of which, 21 I/O pins broken out into a feather form factor layout on this board. All of the ESP32-WROOM Thing Plus (USB-C) pins have a .1" pitch spacing for headers. With the pin multiplexing capabilities of the ESP32 SoC, various pins can have several functionalities. For more technical specifications on the I/O pins, please refer to the ESP32 SoC datasheet.

13x 12-bit analog to digital converter (ADC) channels
3x UARTs (only two are configured by default in the Arduino IDE, one UART is used for bootloading/debug)
3x SPI (only one is configured by default in the Arduino IDE)
2x I²C (only one is configured by default in the Arduino IDE)
2x I²S Audio
2x digital-to-analog converter (DAC) channels
16x 20-bit PWM outputs
8x Capacitive Touch Inputs

Graphical datasheet for the ESP32-WROOM Thing Plus (USB-C). (Click to enlarge)

Note: Users should be aware of the following limitations for the board in the Arduino IDE.

Not all of the features, listed above, are available in the Arduino IDE. For the full capabilities of the ESP32, the Espressif IDF should be utilized.
Only one I²C bus is defined.
Only two UART interfaces are available.

UART (USB): Serial
RX/TX Pins: Serial1

Only one SPI bus is defined.

For digital pins, users will need to declare the pinMode() (link) in the setup of their sketch (programs written in the Arduino IDE) for the pins used.

Input

When configured properly, an input pin will be looking for a HIGH or LOW state. Input pins are High Impedance and takes very little current to move the input pin from one state to another.

Output

When configured as an output the pin will be at a HIGH or LOW voltage. Output pins are Low Impedance: This means that they can provide a relatively substantial amount of current to other circuits.

⚡ Note: There are electrical limitations to the amount of current that the ESP32-WROOM module can sink or source. For more details, check out the ESP32-WROOM module datasheet.

Additional Functions

There are several pins that have special functionality in addition to general digital I/O. These pins and their additional functions are listed in the tabs below. For more technical specifications on the I/O pins, you can refer to the schematic, ESP32-WROOM module datasheet, ESP32 SoC datasheet, and documentation for the ESP32 Arduino core.

Analog Input Pins

The ESP32-WROOM module provides a 12-bit ADC input on thirteen of its I/O pins. This functionality is accessed in the Arduino IDE using the analogRead(pin) function. (*The available ADC pins are highlighted in the image below.)

Analog input pins on the ESP32-WROOM Thing Plus. (Click to enlarge)

Note: By default, in the Arduino IDE, analogRead() returns a 10-bit value. To change the resolution of the value returned by the analogRead() function, use the analogReadResolution(bits) function.

Note: To learn more about analog vs. digital signals, check out this great tutorial.

Analog vs. Digital

July 18, 2013

This tutorial covers the concept of analog and digital signals, as they relate to electronics.

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Pulse Width Modulation (PWM) and Analog (DAC) Output Pins

The ESP32-WROOM module supports up to sixteen channels of 20-bit PWM outputs on any of its I/O pins. This is accessed in the Arduino IDE using the analogWrite(pin, value) function or the LED Control API. (*Any I/O pin can be used for the PWM outputs; the available DAC pins, with true analog outputs, are highlighted in the image below.)

Any I/O pin can be used for a PWM output, but these are the DAC pins on the ESP32-WROOM Thing Plus. (Click to enlarge)

Note: By default, in the Arduino IDE, analogWrite() accepts an 8-bit value. To change the resolution of the PWM signal for the analogWrite() function, use the analogWriteResolution(bits) function.

(*The PWM output is not a true analog signal. For a true analog output, please refer to the DAC API for GPIO 25 and GPIO 26.)

Note: To learn more about pulse width modulation (PWM), check out this great tutorial.

Pulse Width Modulation

February 27, 2013

An introduction to the concept of Pulse Width Modulation.

Favorited Favorite 48

Serial Communication Pins

The ESP32-WROOM module provides three UART ports. By default, the UART port for the USB connection (Serial) and the labeled UART I/O pins on the board (Serial1) can be accessed through the Arduino IDE using the serial communication class.

Default UART ports on the ESP32-WROOM Thing Plus. (Click to enlarge)

Note: By default, in the Arduino IDE, the SparkFun ESP32 Thing Plus C board definition supports:

Serial - UART (USB)
Serial1 - Pins: RX/TX (GPIO 16/GPIO 17)

In order to utilize the serial communication on the strapping pins, users will need to create a custom serial port object and declare which pins to access.

Note: To learn more about serial communication, check out this great tutorial.

Serial Communication

December 18, 2012

Asynchronous serial communication concepts: packets, signal levels, baud rates, UARTs and more!

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Note: We have noticed that with the ESP32 Arduino core, Serial.available() does not operate instantaneously. This is due to an interrupt triggered by the UART, to empty the FIFO when the RX pin is inactive for two byte periods:

At 9600 baud, hwAvailable takes [number of bytes received + 2] x 1 ms = 11 ms before the UART indicates that data was received from: \r\nERROR\r\n.
At 115200 baud, hwAvailable takes [number of bytes received + 2] x .087 ms = ~1 ms before the UART indicates that data was received from: \r\nERROR\r\n.

For more information, please refer to this chatroom discussion.

SPI Communication

The ESP32-WROOM module provides three SPI buses. By default, in the Arduino IDE, the SPI class is configured to utilize pins GPIO 18 (SCK), GPIO 19 (POCI), GPIO 23 (PICO). These pins share the same SPI bus as the µSD card slot, which utilizes pin 5 (SS) for its chip select. In order to utilize the other SPI ports or objects, users will need to create a custom SPI object and declare which pins to access.

Note: To comply with the latest OSHW design practices, we have adopted the new SPI signal nomenclature (SDO/SDI and PICO/POCI). The terms Master and Slave are now referred to as Controller and Peripheral. The MOSI signal on a controller has been replaced with SDO or PICO. Please refer to this announcement on the decision to deprecate the MOSI/MISO terminology and transition to the SDO/SDI naming convention.

Default SPI bus connections on the ESP32-WROOM Thing Plus. (Click to enlarge)

SCK	`GPIO 18` (`SCK`)
SDI or POCI	`GPIO 19` (`MISO`)
SDO or PICO	`GPIO 23` (`MOSI`)
CS (µSD Card)	`GPIO 5` (`SS`)

Note: To learn more about the serial peripheral interface (SPI) protocol, check out this great tutorial.

Serial Peripheral Interface (SPI)

January 14, 2013

SPI is commonly used to connect microcontrollers to peripherals such as sensors, shift registers, and SD cards.

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I²C Communication Pins

The ESP32-WROOM module module can support up to two I²C buses. By default, in the Arduino IDE, the Wire class is configured to utilize pins GPIO 21 (SDA) and GPIO 22 (SCL). These pins share the same I²C bus with the Qwiic connector and MAX17048 fuel gauge. In order to utilize the other I²C ports, users will need to create a custom Wire object and declare which pins to access.

Annotated image of IOM2 I<sup>2</sup>C pins

Default I²C bus connections for the ESP32-WROOM Thing Plus. (Click to enlarge)

SCL	`GPIO 22` (`SCL`)
SDA	`GPIO 21` (`SDA`)

Note: To learn more about the inter-integrated circuit (I²C) protocol, check out this great tutorial.

I2C

July 8, 2013

An introduction to I2C, one of the main embedded communications protocols in use today.

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Buttons

There are two buttons on ESP32-WROOM Thing Plus; a RST and BOOT button.

Reset Button

The RST (reset) button allows users to reset the program running on the ESP32-WROOM module without unplugging the board.

RST button on the ESP32-WROOM Thing Plus. (Click to enlarge)

Boot Button

The BOOT button can be used to force the board into the serial bootloader. Holding down the BOOT button, while connecting the board to a computer through its USB-C connector or resetting the board will cause it to enter the Firmware Download mode. The board will remain in this mode until it power cycles (happens automatically after uploading new firmware) or the RST button is pressed.

Hold the BOOT button down.
Reset the MCU.
- While unpowered, connect the board to a computer with through the USB-C connection.
- While powered, press the RST button.
Release the BOOT button.
After programming is completed, reboot the MCU.
- Press the RST button.
- Power cycle the board.

BOOT button on the ESP32-WROOM Thing Plus. (Click to enlarge)

⚡ Note: The BOOT button is also connected to GPIO 0, which controls the voltage output to the Qwiic connector. Therefore, pressing the BOOT button will momentarily disable power to the Qwiic connector.

Indicator LEDs

There are four indicator LEDs on the ESP32-WROOM Thing Plus:

PWR: Power (Red)
CHG: Battery Charging (Yellow)
13: GPIO 13 (Blue)
WS2812: GPIO 02 (RGB)

Power LED

The red, power (PWR) LED will light up once 3.3V is supplied to the board. For most users, it will light up when 5V is supplied through the USB connection and/or when a LiPo battery is attached to the JST connector.

ESP32-WROOM Thing Plus PWR status LED indicator. (Click to enlarge)

Battery Charging LED

The yellow, battery charging (CHG) LED indicates the status of the MCP73831 charge management controller. The LED will shut off when no battery is present, when the charge management controller is in standby (after the battery charging has been completed), or when the charge management controller is shutdown. The LED will illuminate when the charge management controller is in the process of charging the battery. For more information, please refer to the MCP73831 datasheet.

The battery charging (CHG) LED indicator on the ESP32-WROOM Thing Plus. (Click to enlarge)

Charge Cycle State	LED
Shutdown Thermal Shutdown V_DD < V_BAT	Off (High Z)
No Battery Present	Off (High Z)
Charge Complete – Standby	Off (H)
Preconditioning	On (L)
Constant-Current Fast Charge	On (L)
Constant Voltage	On (L)

STAT LED

The blue, status (STAT) LED is typically used as a test or status LED to make sure that a board is working or for basic debugging. This indicator is connected to GPIO 13.

The status (STAT) LED indicator on the ESP32-WROOM Thing Plus. (Click to enlarge)

WS2812 RGB LED

The WS2812 RGB LED is controlled with a 24-bit (GRB) data signal. This indicator is connected to GPIO 02 and the digital output pin from the LED is available through a test point. For more information, please refer to the WS2812C datasheet.

WS2812 LED indicator on the ESP32-WROOM Thing Plus. (Click to enlarge)

Note: The latest ESP32 Arduino core, now provides a basic RGB LED driver for a WS2812 (or NeoPixel) LED populated the board. For an example of how to utilize the RGB LED driver check out the BlinkRGB example code, which can be accessed from the File drop down menu (i.e File > Examples > ESP32 > GPIO > BlinkRGB).

µSD Slot

Note: To comply with the latest OSHW design practices, we have adopted the new SPI signal nomenclature (SDO/SDI and PICO/POCI). The terms Master and Slave are now referred to as Controller and Peripheral. Please refer to this announcement on the decision to transition to the new naming convention.

The ESP32-WROOM Thing Plus (USB-C) includes an µSD card slot. This is great for data logging applications or storing files. The µSD card slot is connected to the following dedicated GPIO:

GPIO 5: DATA 3/CS
N/A: DATA 2
N/A: DATA 1
GPIO 19: DATA 0/POCI (or Peripheral's SDO)
GPIO 18: CLK/SCK
GPIO 23: CMD/PICO (or Peripheral's SDI)

µSD card slot on the ESP32-WROOM Thing Plus. (Click to enlarge)

Jumpers

There are two jumpers on the back of the board that can be used to easily modify the hardware connections on the board.

SHLD - This jumper can be used to disconnect the USB shield from GND.
PWR - This jumper can be used to remove power to the PWR LED.
CHG LED - This jumper can be used to remove power to the CHG LED.
- Avoid cutting the box's silkscreen; there are traces under it:
  
  Traces around the CHG LED jumper. (Click to enlarge)

The jumpers on the back of the ESP32-WROOM Thing Plus. (Click to enlarge)

Never modified a jumper before? Check out our Jumper Pads and PCB Traces tutorial for a quick introduction!

How to Work with Jumper Pads and PCB Traces

April 2, 2018

Handling PCB jumper pads and traces is an essential skill. Learn how to cut a PCB trace, add a solder jumper between pads to reroute connections, and repair a trace with the green wire method if a trace is damaged.

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Primary I²C Bus

The Qwiic connector and battery fuel gauge are attached to the primary I²C bus. The primary I²C bus for this board utilizes the pin connections, detailed in the table below:

Connection	`VDD`	`GND`	`SCL`	`SDA`
Battery Fuel Gauge (MAX17048)	`VBAT`	GND	`GPIO 22`	`GPIO 21`
Qwiic Connector	`GPIO 0` (Enables 3.3V)	GND	`GPIO 22`	`GPIO 21`

Battery Fuel Gauge

The MAX17048 fuel gauge measures the approximate charge or discharge rate, state of charge (SOC) (based on ModelGauge algorithm), and voltage of a connected battery. Additionally, the chip is powered directly from VBAT, when a LiPo battery is connected. For more information, please refer to the MAX17048 datasheet.

The MAX17048 fuel gauge on the ESP32-WROOM Thing Plus. (Click to enlarge)

I²C Address	0x36 (7-bit) 0x6C (write)/0x6D (read)
Voltage Measurement	Range: 2.5 - 5 V Precision: ±7.5 mV/Cell Resolution 1.25 mV/Cell
Current Consumption	Sleep: .5 - 2 µA Hibernate: 3 - 5 µA Active: 23 - 40 µA

Note: The Alert pin for the MAX17048 is not connected and cannot be utilized.

Qwiic Connector

A Qwiic connector is provided for users to seamlessly integrate with SparkFun's Qwiic Ecosystem.

Qwiic connector and I²C pins on the ESP32-WROOM Thing Plus. (Click to enlarge)

Power Control

In order to enable power for the Qwiic connector, users must toggle GPIO 0 high. This enables the power output from the XC6222 LDO regulator to the Qwiic connector, which can sources up to 700mA at 3.3V . In order to conserve battery power or in low power applications, users will can toggle GPIO 0 low, to disable the power to the Qwiic connector.

⚡ Note: GPIO 0 is also connected to the BOOT button. Therefore, pressing the BOOT button will momentarily disable power to the Qwiic connector.

What is Qwiic?

The Qwiic system is intended a quick, hassle-free cabling/connector system for I²C devices. Qwiic is actually a play on words between "quick" and I²C or "iic".

Features of the Qwiic System

Keep your soldering iron at bay.

Cables plug easily between boards making quick work of setting up a new prototype. We currently offer three different lengths of Qwiic cables as well as a breadboard friendly cable to connect any Qwiic enabled board to anything else. Initially you may need to solder headers onto the shield to connect your platform to the Qwiic system but once that’s done it’s plug and go!

Qwiic cables connected to Spectral Sensor Breakout

Minimize your mistakes.

How many times have you swapped the SDA and SCL wires on your breadboard hoping the sensor will start working? The Qwiic connector is polarized so you know you’ll have it wired correctly, every time, from the start.

The PCB connector is part number SM04B-SRSS (Datasheet) or equivalent. The mating connector used on cables is part number SHR04V-S-B or equivalent. This is a common and low cost connector.

1mm pitch, 4-pin JST connector

Expand with ease.

It’s time to leverage the power of the I²C bus! Most Qwiic boards will have two or more connectors on them allowing multiple devices to be connected.

Shown above: Qwiic Shield for Arduino on RedBoard, Spectral Sensor Breakout - NIR, Spectral Sensor Breakout - Visible and SparkFun GPS Breakout

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Hardware Assembly

← Previous Page
Introduction

ESP32 Thing Plus (USB-C) Hookup Guide

Hardware Overview

Board Dimensions

USB-C Connector

CH340 Serial-to-UART

Power

Power Status LED

Charging Circuit

Power Control

Current Consumption

ESP32-WROOM

Debugging

Firmware Download Mode

Peripherals and I/O

Input

Output

Additional Functions

Analog Input Pins

Analog vs. Digital

July 18, 2013

Pulse Width Modulation (PWM) and Analog (DAC) Output Pins

Pulse Width Modulation

February 27, 2013

Serial Communication Pins

Serial Communication

December 18, 2012

SPI Communication

Serial Peripheral Interface (SPI)

January 14, 2013

I2C Communication Pins

I2C

July 8, 2013

Buttons

Reset Button

Boot Button

Indicator LEDs

Power LED

Battery Charging LED

STAT LED

WS2812 RGB LED

µSD Slot

Jumpers

How to Work with Jumper Pads and PCB Traces

April 2, 2018

Primary I2C Bus

Battery Fuel Gauge

Qwiic Connector

Power Control

Features of the Qwiic System

Keep your soldering iron at bay.

Minimize your mistakes.

Expand with ease.

I²C Communication Pins

Primary I²C Bus