ESPRESSIF ESP32-­C3­-WROOM­-02 WiFi/Bluetooth Module User Manual

**ESPRESSIF ESP32-­C3­-WROOM­-02 WiFi/Bluetooth Module

**

About This Document
This user manual shows how to get started with the ESP32-C3-WROOM-02 module.
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Please always refer to the latest version on https://www.espressif.com/en/support/download/documents.
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Overview

Module Overview

ESP32-C3-WROOM-02 is a general-purpose Wi-Fi and Bluetooth LE module. The rich set of peripherals and a small size make this module an ideal choice for smart homes, industrial automation, health care, consumer electronics, etc.

Table 1: ESP32­C3­WROOM­02 Specifications

Bluetooth®

| Protocols| Bluetooth® LE: Bluetooth 5 and Bluetooth mesh
Radio| Class-1, class-2 and class-3 transmitter
AFH
Audio| CVSD and SBC

Hardware

|

Module interfaces

| GPIO, SPI, UART, I2C, I2S, remote control peripheral, LED PWM controller, general DMA controller, TWAI® controller (compatible with ISO 11898-1), temperature

sensor, SAR ADC

Integrated crystal| 40 MHz crystal
Integrated SPI flash| 4 MB
Operating voltage/Power supply| 3.0 V ~ 3.6 V
Operating current| Average: 80 mA
Minimum current delivered by power

supply

| 500 mA
Ambient temperature| 85 °C version: –40 °C ~ +85 °C;
105 °C version: –40 °C ~ +105 °C
Moisture sensitivity level (MSL)| Level 3

Pin Description

The module has 19 pins. See pin definitions in Table 2.
For peripheral pin configurations, please refer to ESP32-C3 Family Datasheet .

Table 2: Pin Definitions

EN

|

2

|

I

| High: on, enables the chip. Low: off, the chip powers off.

Note: Do not leave the EN pin floating.

IO4| 3| I/O/T| GPIO4, MTMS, ADC1_CH4, FSPIHD
IO5| 4| I/O/T| GPIO5, MTDI, ADC2_CH0, FSPIWP
IO6| 5| I/O/T| GPIO6, MTCK, FSPICLK
IO7| 6| I/O/T| GPIO7, MTDO, FSPID
IO8| 7| I/O/T| GPIO8
IO9| 8| I/O/T| GPIO9
GND| 9, 19| P| Ground
IO10| 10| I/O/T| GPIO10, FSPICS0
RXD0| 11| I/O/T| U0RXD, GPIO20

Table 2 – cont’d from previous page

Get Started on ESP32­C3­WROOM­02

What You Need
To develop applications for ESP32-C3-WROOM-02 module you need:

• 1 x ESP32-C3-WROOM-02 module
• 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 Linux operating system as an example. For more information about the configuration on Windows and macOS, please refer to

ESP-IDF Programming Guide.

Hardware Connection

1. Solder the ESP32-C3-WROOM-02 module to the RF testing board as shown in Figure 2.
2. Connect the RF testing board to the USB-to-Serial board via TXD, RXD, and GND.
3. Connect the USB-to-Serial board to the PC.
4. Connect the RF testing board to the PC or a power adapter to enable 5 V power supply, via the Micro-USB cable.
5. During download, connect IO0 to GND via a jumper, and pull up IO8. Then, turn ”ON” the testing board.
6.  Download firmware into flash. For details, see the sections below.
7. After download, remove the jumper on IO0 and GND, and the jumper wire to pull up IO8.
8. Power up the RF testing board again. ESP32-C3-WROOM-02 will switch to working mode. The chip will read programs from flash upon initialization.

Note:
IO0 is internally logic high. If IO0 is pulled low, and IO8 is pulled high, the Boot mode is selected. In other cases, the Download mode is selected. For more information on ESP32-C3-WROOM-02, please refer to
ESP32-C3-WROOM-02 & ESP32-C3-WROOM-02U Datasheet . 

Set up Development Environment

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

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

   • CentOS 7:
     1 sudo yum install git wget flex bison gperf python cmake ninja-build ccache dfuutil

   • Ubuntu and Debian (one command breaks into two lines):
     1 sudo apt-get install git wget flex bison gperf python python-pip pythonsetuptools
     cmake
     2 ninja-build ccache libffi-dev libssl-dev dfu-util

   • Arch:
     1 sudo pacman -S –needed gcc git make flex bison gperf python-pip cmake ninja
     ccache dfu-util

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 ESP­IDF
To build applications for ESP32-C3-WROOM-02 module, you need the software libraries provided by Espressif in ESP-IDF repository.
To get ESP-IDF, create an installation directory (~/esp) to download ESP-IDF to and clone the repository with ‘git clone’:

1. mkdir -p ~/esp
2. cd ~/esp
3. git clone –recursive https://github.com/espressif/esp-idf.git

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.

1. cd ~/esp/esp-idf
2. install.sh

Set up Environment Variables

The installed tools are not yet 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:

•  $HOME/esp/esp-idf/export.sh
  Now everything is ready, you can build your first project on ESP32-C3-WROOM-02 module.

Create Your First Project

Start a Project

Now you are ready to prepare your application for ESP32-C3-WROOM-02 module. You can start with get-started/hello_world project from examples directory in ESP-IDF.
Copy get-started/hello_world to ~/esp directory:

1. cd ~/esp
2. cp -r $IDF_PATH/examples/get-started/hello_world .

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 ESP32-C3-WROOM-02 module to the computer and check under what 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 plugged in. The port which appears the second time is the one you need:

1. ls /dev/tty*

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

Configure
Navigate to your ‘hello_world’ directory from Step 2.4.1. Start a Project, set ESP32-C3 as the target and run the project configuration utility ‘menuconfig’.

1. cd ~/esp/hello_world
2. idf.py set-target esp32c3
3. idf.py menuconfig

Setting the target with ‘idf.py set-target esp32c3’ should be done once, after opening a new project. If the project contains some existing builds and configuration, they will be cleared and initialized. The target may be saved in environment variable to skip this step at all. See Selecting the Target for additional information.
If the previous steps have been done correctly, the following menu appears:

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:

1. idf.py build

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

1. idf.py build
2. Running cmake in directory /path/to/hello_world/build
3. Executing ”cmake -G Ninja –warn-uninitialized /path/to/hello_world”…
4. Warn about uninitialized values.
5. — Found Git: /usr/bin/git (found version ”2.17.0”)
6. — Building empty aws_iot component due to configuration
7. — Component names: …
8. — Component paths: …
9. 10. … (more lines of build system output)
10. 12. [527/527] Generating hello-world.bin
11. esptool.py v2.3.1
12. 15. Project build complete. To flash, run this command:
13. ../../../components/esptool_py/esptool/esptool.py -p (PORT) -b 921600 writeflash –flash mode dio
14. –flash_size detect –flash_freq 40m 0x10000 build/hello-world.bin
15. build 0x1000 build/bootloader/bootloader.bin 0x8000 build/partition_table/partition-table.bin
16. or run ’idf.py -p PORT flash’

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 ESP32-C3-WROOM-02 module by running:

1. idf.py -p PORT [-b BAUD] flash

Replace PORT with your module‘s serial port name from Step: Connect Your Device.
You can also change the flasher 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.

1. …

2. esptool.py –chip esp32c3 -p /dev/ttyUSB0 -b 460800 –before=default_reset –after
   =hard_reset write_flash –flash_mode dio –flash_freq 80m –flash_size 2MB 0x
   8000 partition_table/partition-table.bin 0x0 bootloader/bootloader.bin 0x10000
   hello-world.bin

3.  esptool.py v3.0

4.  Serial port /dev/ttyUSB0

5. Connecting….

6. Chip is ESP32-C3

7. Features: Wi-Fi

8.  Crystal is 40MHz

9. MAC: 7c:df:a1:40:02:a4

10. Uploading stub…

11. Running stub…

12. Stub running…

13. Changing baud rate to 460800

14. Changed.

15. Configuring flash size…

16. Compressed 3072 bytes to 103…

17. Writing at 0x00008000… (100 %)

18. Wrote 3072 bytes (103 compressed) at 0x00008000 in 0.0 seconds (effective 4238.1
    kbit/s)…

19. Hash of data verified.

20. Compressed 18960 bytes to 11311…

21. Writing at 0x00000000… (100 %)

22. Wrote 18960 bytes (11311 compressed) at 0x00000000 in 0.3 seconds (effective 584.9
    kbit/s)…

23. Hash of data verified.

24. Compressed 145520 bytes to 71984…

25. Writing at 0x00010000… (20 %)

26. Writing at 0x00014000… (40 %)

27. Writing at 0x00018000… (60 %)

28. Writing at 0x0001c000… (80 %)

29. Writing at 0x00020000… (100 %)

30. Wrote 145520 bytes (71984 compressed) at 0x00010000 in 2.3 seconds (effective
    504.4 kbit/s)…

31. Hash of data verified.

32. 33. Leaving…

33. Hard resetting via RTS pin…

34. Done

If everything goes well, the “hello_world” application starts running after you remove the jumper on IO0 and GND, and re-power up the testing board.

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:

1. idf.py -p /dev/ttyUSB0 monitor
2. Running idf_monitor in directory […]/esp/hello_world/build
3. Executing ”python […]/esp-idf/tools/idf_monitor.py -b 115200 […]/esp/hello_world/build /hello-world.elf”…
4. — idf_monitor on /dev/ttyUSB0 115200 —
5. — Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H —
6. ets Jun 8 2016 00:22:57
7. 8. rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
8.  ets Jun 8 2016 00:22:57
9. …

After startup and diagnostic logs scroll up, you should see “Hello world!” printed out by the application.

1. …
2. Hello world!
3. Restarting in 10 seconds…
4. This is esp32c3 chip with 1 CPU core, WiFi/BLE Restarting in 9 seconds…
5. Restarting in 8 seconds…
6. Restarting in 7 seconds…

To exit IDF monitor use the shortcut Ctrl+].

That’s all what you need to get started with ESP32-C3-WROOM-02 module! Now you are ready to try some other examples in ESP-IDF, or go right to developing your own 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 & 15.209

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: 3.26 dBi Max

The module can be used for IoT applications with a maximum 3.26 dBi antenna. The host manufacturer installing this module into their product must ensure that the final composit product complies with the FCC requirements by a technical assessment or evaluation to 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 which integrates this module. The end user manual shall include all required regulatory information/warning as show in this manual.

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

Trace Antenna Designs
Not applicable. The module has its own 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 required to take responsibility of the module through a change in FCC ID or 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 specification are as follows:

• Type: On-board PCB antenna
• Gain: 3.26 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 only used with the external antenna(s) that has 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 test will not be required. However, the host manufac-turer 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-ESPC3WROOM” 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: 12
  • Bluetooth: 40
• Modulation:
  • WiFi: DSSS; OFDM
  • Bluetooth: GFSK;

Host manufacturer must perform test 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 can 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 & 15.209 and that the host product manufacturer is responsible for compliance to 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 circuity), 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, pursuant to Part15 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 in accordance with 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 into 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 opera-tion.

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 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 only used with the external antenna(s) that has been originally tested and certified with this module.

As long as the conditions above are met, further transmitter test 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

In the event that 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 final end product must be labeled in a visible area with the following: “Contains Transmitter Module FCC ID: 2AC7Z-ESPC3WROOM”.

IC Statement

This device complies with Industry Canada’s licence-exempt RSSs. Operation is subject to the following two conditions:

• This device may not cause interference; and
• This device must accept any interference, including interference that may cause undesired operation of the device.

Radiation Exposure Statement
This equipment complies with IC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20 cm between the radiator and your body.

This device is intended only for OEM integrators under the following conditions (For module device use):

• The antenna must be installed such that 20 cm is maintained between the antenna and users, and
• The transmitter module may not be co-located with any other transmitter or antenna.

As long as 2 conditions above are met, further transmitter test 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.

IMPORTANT NOTE:

In the event that these conditions can not be met (for example certain laptop configurations or colocation with another transmitter), then the Canada authorization is no longer considered valid and the IC ID can not 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 Canada authorization.

End Product Labeling

This transmitter module is authorized only for use in device where the antenna may be installed such that 20 cm may be maintained between the antenna and users. The final end product must be labeled in a visible area with the following: “Contains IC: 21098-ESPC3WROOM”.

Manual Information to the End User

The OEM integrator 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 which integrates this module. The end user manual shall include all required regulatory information/warning as show in this manual.

This radio transmitter [IC:21098-ESPC3WROOM] has been approved by Innovation, Science and Economic De-velopment Canada to operate with the antenna types listed below, with the maximum permissible gain indi-cated.

• Type: On-board PCB antenna
• Gain: 3.26 dBi
• Antenna input impedance50ohm

Antenna types not included in this list that have a gain greater than the maximum gain indicated for any type listed are strictly prohibited for use with this device.

Learning Resources

Must­Read Documents

Please familiarize yourself with the following documents:

• ESP32-C3 Family Datasheet
  This is an introduction to the specifications of the ESP32-C3 hardware, including overview, pin definitions, functional description, peripheral interface, electrical characteristics, etc.

• ESP-IDF Programming Guide
  Extensive documentation for the ESP-IDF development framework, ranging from hardware guides to API reference.

• ESP32-C3 Technical Reference Manual
  Detailed information on how to use the ESP32-C3 memory and peripherals.

Important Resources

Here are the important ESP32-C3-related resources.

• ESP32 BBS
  Engineer-to-Engineer (E2E) Community for Espressif products where you can post questions, share knowl-edge, explore ideas, and help solve problems with fellow engineers.

Revision History

Disclaimer and Copyright Notice

Information in this document, including URL references, is subject to change without notice.
ALL THIRD-PARTY’S INFORMATION IN THIS DOCUMENT IS PROVIDED AS-IS WITH NO WARRANTIES TO ITS AUTHENTICITY AND ACCURACY.
NO WARRANTY IS PROVIDED TO THIS DOCUMENT FOR ITS MERCHANTABILITY, NON- INFRINGEMENT, OR 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 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 and registered trademarks mentioned in this document are property of their respective owners, and are hereby acknowledged.
Copyright © 2022 Espressif Systems (Shanghai) Co., Ltd. All rights reserved.

www.espressif.com 

References

• Wireless SoCs, Software, Cloud and AIoT Solutions | Espressif Systems
• Certificates | Espressif Systems
• Subscribe | Espressif Systems
• Build System - ESP32-S2 - — ESP-IDF Programming Guide latest documentation
• Build System - ESP32-S2 - — ESP-IDF Programming Guide latest documentation
• ESP-IDF Versions - ESP32-S2 - — ESP-IDF Programming Guide latest documentation
• GitHub - espressif/esp-idf: Espressif IoT Development Framework. Official development framework for Espressif SoCs.
• esp-idf/examples/get-started/hello_world at c77c4ccf6c43ab09fd89e7c907bf5cf2a3499e3b · espressif/esp-idf · GitHub
• esp-idf/examples at master · espressif/esp-idf · GitHub
• ESP32 Forum - Index page

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