ESPRESSIF SYSTEMS ESP8684-WROOM-060 ESP32 C2 Module User Manual

Set up Tools: Configure development tools for programming.
Set up Environment Variables: Set necessary environment variables for the development environment.

Create Your First Project

Start a Project
Create a new project in your development environment.

Connect Your Device
Establish a connection between your development environment and the ESP8684-WROOM-06C module.

Configure
Configure the project settings and parameters according to your requirements.

Build the Project
Compile the project to generate the firmware image.

Flash onto the Device
Flash the compiled firmware onto the ESP8684-WROOM-06C module.

Monitor
Monitor the device behavior and output for testing and debugging purposes.

Module Overview

Features

CPU and On-Chip Memory

ESP8684H2 or ESP8684H4 embedded, 32-bit RISC-V single-core processor, up to 120 MHz

576 KB ROM
272 KB SRAM (16 KB for cache)

In-Package flash (see details in Table 1 ESP8684-WROOM-06C Series Comparison)
Access to flash is accelerated by cache

Supports flash in-circuit Programming (ICP)

Wi-Fi

IEEE 802.11 b/g/n-compliant
Center frequency range ofthe operating channel:
2412 ~ 2462 MHz

Supports 20 MHz bandwidth in the 2.4 GHz band
1T1R mode with data rate up to 72.2 Mbps

Wi-Fi Multimedia (WMM)
TX/RX A-MPDU, TX/RX A-MSDU
Immediate Block ACK
Fragmentation and defragmentation
Transmit opportunity (TXOP)
Automatic Beacon monitoring (hardware TSF)
3 × virtual Wi-Fi interfaces
Simultaneous support for Infrastructure BSS in Station mode, SoftAP mode, Station + SoftAP mode, and promiscuous mode
Note that when the ESP8684 series scans in Station mode, the SoftAP channel will change along with the Station channel.

Bluetooth®

Bluetooth LE: Bluetooth 5.3 certified
High power mode (20 dBm)
Speed: 125 kbps, 500 kbps, 1 Mbps, 2 Mbps
Advertising extensions
Multiple advertisement sets
Channel selection algorithm #2
Internal co-existence mechanism between Wi-Fi and Bluetooth to share the same antenna

Peripherals
GPIO, SPI, UART, I2C, LED PWM controller, general DMA controller, temperature sensor, SAR ADC, timers, and watchdog
Note:
* Please refer to the ESP8684 Series Datasheet for detailed information about the module peripherals.

Integrated Components on Module
26 MHz crystal oscillator

Antenna Options
On-board PCB antenna

Operating Conditions

Operating voltage/Power supply: 3.0 ~ 3.6 V
Operating ambient temperature: –40 ~ 105 °C

Certification

Bluetooth certification: BQB
Green certification: RoHS/REACH

Test
HTOL/HTSL/uHAST/TCT/ESD/Latch-up

Description

ESP8684-WROOM-06C is a powerful, generic Wi-Fi and Bluetooth LE module. This module is an ideal choice for smart homes, industrial automation, health care, consumer electronics, etc.
ESP8684-WROOM-06C can be mounted onto the surface of a PCB board via reflow soldering or vertically soldered to a PCB board via wave soldering. When surface mounted, the module has 14 available GPIOs; when vertically soldered, the module has 5 available GPIOs.

ESP8684-WROOM-06C comes with an on-board PCB antenna.
The series comparison for ESP8684-WROOM-06C is as follows:

Ordering Code In-Package flash Ambient Temp.1
(°C)
Size
(mm)

ESP8684-WROOM-06C-H2 2 MB –40 ~105 15.8 × 20.3 × 2.7

ESP8684-WROOM-06C-H4 4 MB

Ambient temperature specifies the recommended temperature range of the environment immediately outside the Espressif module.

The ESP8684H2 chip and the ESP8684H4 chip fall into the same category, namely the ESP8684 chip series.The
ESP8684 series of chips has a 32-bit RISC-V single-core processor. They integrate a rich set of peripherals, including UART, I2C, LED PWM controller, general DMA controller, temperature sensor, SAR ADC, etc.
Note:
* For more information on ESP8684 chip, please refer to ESP8684 Series Datasheet.

Pin Definitions

Pin Layout
The pin diagram below shows the approximate location of pins on the module.

Pin Description

The module has 22 pins. See pin definitions in Table 2, Pin Definitions.

For peripheral pin configurations, please refer to the ESP8684 Series Datasheet.

Name	No.	Type1	Function
IO1	1	I/O/T	GPIO1, ADC1_CH1
IO2	2	I/O/T	GPIO2, ADC1_CH2, FSPIQ
NC	3	—	NC
NC	4	—	NC
IO0	5	I/O/T	GPIO0, ADC1_CH0
RX0	6	I/O/T	GPIO19, U0RXD
TX0	7	I/O/T	GPIO20, U0TXD
IO3	8	I/O/T	GPIO3, ADC1_CH3, LED PWM
IO7	9	I/O/T	GPIO7, FSPID, MTDO, LED PWM
IO6	10	I/O/T	GPIO6, FSPICLK, MTCK, LED PWM
IO4	11	I/O/T	GPIO4, ADC1_CH4, FSPIHD, MTMS, LED PWM
IO5	12	I/O/T	GPIO5, FSPIWP, MTDI, LED PWM
GND	13	P	Ground
3V3	14	P	Power supply
IO18	15	I/O/T	GPIO18
IO10	16	I/O/T	GPIO10, FSPICS0
NC	17	—	NC
EN	18	I	High: One enables the chip. Low: off, The chip powers off. Default: internally pulled up.
NC	19	—	NC
IO9 2	20	I/O/T	GPIO9
IO8	21	I/O/T	GPIO8
EPAD	22	P	Ground

P: power supply; I: input; O: output; T: high impedance.
This pin can be used as a test point.
Note:
IO0, IO1, IO3, and IO5/MTDI pins have low-level glitches during chip power-up. See details in the section General Purpose Input / Output Interface (GPIO) of the ESP8684 Series Datasheet.

Get Started

What You Need
To develop applications for the module, you need:

1 x ESP8684-WROOM-06C
1 x Espressif RF testing board

1 x USB-to-Serial board
1 x Micro-USB cable
1 x PC running Linux
In this user guide, we take the Linux operating system as an example. For more information about the configuration on Windows and macOS, please refer to the ESP-IDF Programming Guide.

Hardware Connection

Solder the ESP8684-WROOM-06C module to the RF testing board as shown in Figure 2.

Connect the RF testing board to the USB-to-Serial board via TXD, RXD, and GND.
Connect the USB-to-Serial board to the PC.
Connect the RF testing board to the PC or a power adapter to enable a 5 V power supply via the Micro-USB cable.

During download, connect IO0 to GND via a jumper. Then, turn ”ON” the testing board.
Download firmware into the flash. For details, see the sections below.
After download, remove the jumper on IO0 and GND.

Power up the RF testing board again. The module will switch to working mode. The chip will read programs from flash upon initialization.
Note:
IO0 is internally logic high. If IO0 is set to pull-up, the Boot mode is selected. If this pin is pulled down or left floating, the Download mode is selected. For more information on ESP8684-WROOM-06C, please refer to the ESP8684 Series Datasheet.

Set up Development Environment

The Espressif IoT Development Framework (ESP-IDF for short) is a framework for developing applications based on the Espressif ESP32. Users can develop applications with ESP8684 in Windows/Linux/macOS based on ESP-IDF. Here we take the Linux operating system as an example.

Install Prerequisites
To compile with ESP-IDF, you need to get the following packages:

CentOS 7 & 8:
Ubuntu and Debian:
Arch:

Note:
- This guide uses the directory ~/esp on Linux as an installation folder for ESP-IDF.
- Keep in mind that ESP-IDF does not support spaces in paths.

Get ESP-IDF

To build applications for the ESP8684-WROOM-06C module, you need the software libraries provided by Espressif in the ESP-IDF repository.
To get ESP-IDF, create an installation directory (~/esp) to download ESP-IDF to and clone the repository with ‘git clone’:

ESP-IDF will be downloaded into ~/esp/esp-idf. Consult ESP-IDF Versions for information about which ESP-IDF version to use in a given situation.

Set up Tools
Aside from the ESP-IDF, you also need to install the tools used by ESP-IDF, such as the compiler, debugger, Python packages, etc. ESP-IDF provides a script named ’install.sh’ to help set up the tools in one go.

Set up Environment Variables
The installed tools have not yet been added to the PATH environment variable. To make the tools usable from the command line, some environment variables must be set. ESP-IDF provides another script,’ export.sh’, which does that. In the terminal where you are going to use ESP-IDF, run:

Now everything is ready, you can build your first project on the ESP8684-WROOM-06C module.

Create Your First Project

Start a Project

Now you are ready to prepare your application for the ESP8684-WROOM-06C module. You can start with the get-started/hello_world project from the examples directory in ESP-IDF.
Copy get-started/hello_world to ~/esp directory:
There is a range of example projects in the examples directory in ESP-IDF. You can copy any project in the same way as presented above and run it. It is also possible to build examples in place, without copying them first.

Connect Your Device
Now connect your module to the computer and check under which serial port the module is visible. Serial ports in Linux start with ‘/dev/tty’ in their names. Run the command below two times, first with the board unplugged, then with it plugged in. The port that appears the second time is the one you need:

Note:
Keep the port name handy as you will need it in the next steps.

Configure

Navigate to your ‘hello_world’ directory from Step 3.4.1. Start a Project, set ESP8684 chip as the target, and run the project configuration utility ‘menuconfig’.
Setting the target with ‘idf.py set-target ESP8684’ should be done once, after opening a new project. If the project contains some existing builds and configurations, they will be cleared and initialized. The target may be saved in an environment variable to skip this step all. See Selecting the Target for additional information.

If the previous steps have been done correctly, the following menu appears:
You are using this menu to set up project-specific variables, e.g., Wi-Fi network name and password, the processor speed, etc. Setting up the project with menuconfig may be skipped for “hello_world”. This example will run with the default configuration.

The colors of the menu could be different in your terminal. You can change the appearance with the option ‘-̉-style’̉. Please run ‘idf.py menuconfig -̉-help’̉ for further information.

Build the Project

Build the project by running:
This command will compile the application and all ESP-IDF components, then it will generate the bootloader, partition table, and application binaries.

If there are no errors, the build will finish by generating the firmware binary .bin file.

Flash onto the Device

Flash the binaries that you just built onto your module by running:
Replace PORT with your ESP8684 board’s serial port name from Step: Connect Your Device.
You can also change the flash baud rate by replacing BAUD with the baud rate you need. The default baud rate is 460800.

For more information on idf.py arguments, see idf.py.
Note:
The option ‘flash‘ automatically builds and flashes the project, so running ‘idf.py build‘ is not necessary.
When flashing, you will see the output log similar to the following:

If there are no issues by the end of the flash process, the board will reboot and start up the “hello_world” application.

Monitor

To check if “hello_world” is indeed running, type ‘idf.py -p PORT monitor‘ (Do not forget to replace PORT with your serial port name).

This command launches the IDF Monitor application:
After startup and diagnostic logs scroll up, you should see “Hello world!” printed out by the application.
To exit IDF monitor, use the shortcut Ctrl+].
That’s all you need to get started with the ESP8684-WROOM-06C module! Now you are ready to try some other examples in ESP-IDF, or go right to develop your applications.

U.S. FCC Statement

The device complies with KDB 996369 D03 OEM Manual v01. Below are integration instructions for host product manufacturers according to the KDB 996369 D03 OEM Manual v01.

List of Applicable FCC Rules
FCC Part 15 Subpart C 15.247

Specific Operational Use Conditions
The module has WiFi and BLE functions.

Operation Frequency:
- WiFi: 2412 ~ 2462 MHz
- Bluetooth: 2402 ~ 2480 MHz

Number of Channel:
- WiFi: 11
- Bluetooth: 40

Modulation:
- WiFi: DSSS; OFDM
- Bluetooth: GFSK;
Type: On-board PCB Antenna
Gain: 2.7 dBi Max
The module can be used for IoT applications with a maximum 2.7 dBi antenna. The host manufacturer installing this module into their product must ensure that the final composite product complies with the FCC requirements by a technical assessment or evaluation of the FCC rules, including the transmitter operation. The host manufacturer has to be aware not to provide information to the end user regarding how to install or remove this RF module in the user’s manual of the end product that integrates this module. The end user manual shall include all required regulatory information/warnings as shown in this manual.

Limited Module Procedures
Not applicable. The module is a single module and complies with the requirements of FCC Part 15.212.

Trace Antenna Designs
Not applicable. The module has its antenna, and does not need a host’s printed board microstrip trace antenna, etc.

RF Exposure Considerations
The module must be installed in the host equipment such that at least 20cm is maintained between the antenna and users’ body; and if RF exposure statement or module layout is changed, then the host product manufacturer is required to take responsibility for the module through a change in the FCC ID or a new application. The FCC ID of the module cannot be used on the final product. In these circumstances, the host manufacturer will be responsible for re-evaluating the end product (including the transmitter) and obtaining a separate FCC authorization.

Antennas

Antenna specifications are as follows:
- Type: PCB Antenna
- Gain: 2.7 dBi
This device is intended only for host manufacturers under the following conditions:
- The transmitter module may not be co-located with any other transmitter or antenna.
- The module shall be used only with the external antenna(s) that have been originally tested and certified with this module.
- The antenna must be either permanently attached or employ a ‘unique’ antenna coupler.
As long as the conditions above are met, further transmitter tests will not be required. However, the host manufacturer is still responsible for testing their end-product for any additional compliance requirements required with this module installed (for example, digital device emissions, PC peripheral requirements, etc.).

Label and Compliance Information
Host product manufacturers need to provide a physical or e-label stating “Contains FCC ID: 2AC7Z-ESP868406C” with their finished product.

Information on test modes and additional testing requirements

Operation Frequency:
- WiFi: 2412 ~ 2462 MHz
- Bluetooth: 2402 ~ 2480 MHz
Number of Channel:
- WiFi: 11
- Bluetooth: 40
Modulation:
- WiFi: DSSS; OFDM
- Bluetooth: GFSK;
  Host manufacturers must perform tests of radiated and conducted emission and spurious emission, etc., according to the actual test modes for a stand-alone modular transmitter in a host, as well as for multiple simultaneously transmitting modules or other transmitters in a host product. Only when all the test results of test modes comply with FCC requirements, then the end product be sold legally.

Additional testing, Part 15 Subpart B compliant

The modular transmitter is only FCC authorized for FCC Part 15 Subpart C 15.247, and the host product manufacturer is responsible for compliance with any other FCC rules that apply to the host not covered by the modular transmitter grant of certification. If the grantee markets their product as being Part 15 Subpart B compliant (when it also contains unintentional-radiator digital circuitry), then the grantee shall provide a notice stating that the final host product still requires Part 15 Subpart B compliance testing with the modular transmitter installed.
This equipment has been tested and found to comply with the limits for a Class B digital device, under Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used according to the instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one of the following measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and receiver.
- Connect the equipment to an outlet on a circuit different from that to which the receiver is connected.
- Consult the dealer or an experienced radio/TV technician for help.
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
- This device may not cause harmful interference.
- This device must accept any interference received, including interference that may cause undesired operation.
  Caution:
  Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.
This equipment complies with the FCC RF radiation exposure limits set forth for an uncontrolled environment. This device and its antenna must not be co-located or operating in conjunction with any other antenna or transmitter. The antennas used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter.

OEM Integration Instructions
This device is intended only for OEM integrators under the following conditions:

The transmitter module may not be co-located with any other transmitter or antenna.
The module shall be used only with an antenna that has been originally tested and certified with this module.
As long as the conditions above are met, further transmitter tests will not be required. However, the OEM integrator is still responsible for testing their end-product for any additional compliance requirements required with this module installed (for example, digital device emissions, PC peripheral requirements, etc.).

Validity of Using the Module Certification
If these conditions cannot be met (for example, certain laptop configurations or co-location with another transmitter), then the FCC authorization for this module in combination with the host equipment is no longer considered valid, and the FCC ID of the module cannot be used on the final product. In these circumstances, the OEM integrator will be responsible for re-evaluating the end product (including the transmitter) and obtaining a separate FCC authorization.

End Product Labeling
The end product must be labeled in a visible area with the following: “Contains Transmitter Module FCC ID: 2AC7Z-ESP868406C”.

Disclaimer and Copyright Notice

Information in this document, including URL references, is subject to change without notice.
ALL THIRD-PARTY INFORMATION IN THIS DOCUMENT IS PROVIDED AS IS WITH NO WARRANTIES OF ITS AUTHENTICITY AND ACCURACY.
NO WARRANTY IS PROVIDED TO THIS DOCUMENT FOR ITS MERCHANTABILITY, NONINFRINGEMENT, FITNESS FOR ANY PARTICULAR PURPOSE, NOR DOES ANY WARRANTY OTHERWISE ARISING OUT OF ANY PROPOSAL, SPECIFICATION, OR SAMPLE.
All liability, including liability for infringement of any proprietary rights, relating to the use of information in this document is disclaimed. No licenses express or implied, by estoppel or otherwise, to any intellectual property rights are granted herein.
The Wi-Fi Alliance Member logo is a trademark of the Wi-Fi Alliance. The Bluetooth logo is a registered trademark of Bluetooth SIG.
All trade names, trademarks, a nd registered trademarks mentioned in this document are the property of their respective owners and are hereby acknowledged.

Frequently Asked Questions (FAQ)

Can I use both Wi-Fi and Bluetooth functionalities simultaneously on the ESP8684-WROOM-06C?
Yes, the module supports both Wi-Fi and Bluetooth functionalities concurrently, enabling various applications that require dual wireless capabilities.
What is the recommended ambient temperature range for operating the ESP8684-WROOM-06C?
The recommended ambient temperature range for the module is specified in the datasheet and should be adhered to for optimal performance and longevity.

Documents / Resources

ESPRESSIF SYSTEMS ESP8684-WROOM-060 ESP32 C2 Module [pdf] User Manual
2AC7Z-ESP868406C, 2AC7ZESP868406C, esp868406c, ESP8684-WROOM-060 ESP32 C2 Module, ESP8684-WROOM-060, ESP32 C2 Module, C2 Module

References

User Manual

ESPRESSIF SYSTEMS ESP8684-WROOM-060 ESP32 C2 Module

Product Specifications

Product Usage Instructions

Get Started

Create Your First Project

Module Overview

Features

Pin Definitions

Get Started

Set up Development Environment

Create Your First Project

U.S. FCC Statement

Related Documentation and Resources Related Documentation

Disclaimer and Copyright Notice

Frequently Asked Questions (FAQ)

Documents / Resources

References

Leave a comment

Cancel reply

Ordering Code	In-Package flash	Ambient Temp.1 (°C)	Size (mm)
ESP8684-WROOM-06C-H2	2 MB	–40 ~105	15.8 × 20.3 × 2.7
ESP8684-WROOM-06C-H4	4 MB	–40 ~105	15.8 × 20.3 × 2.7