Espressif ESP8685-WROOM-03 User manual

ESP8685WROOM03
User Manual
Pre-release v0.1
Espressif Systems
Copyright © 2021
www.espressif.com

About This Document
This user manual shows how to get started with the ESP8685-WROOM-03 module.
Document Updates
Please always refer to the latest version on https://www.espressif.com/en/support/download/documents.
Revision History
For revision history of this document, please refer to the last page.
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Certification
Download certificates for Espressif products from www.espressif.com/en/certificates.

Contents
Contents
1 Overview 4
1.1 Module Overview 4
1.2 Pin Description 4
2 Get Started on ESP8685WROOM03 6
2.1 What You Need 6
2.2 Hardware Connection 6
2.3 Set up Development Environment 7
2.3.1 Install Prerequisites 7
2.3.2 Get ESP-IDF 7
2.3.3 Set up Tools 8
2.3.4 Set up Environment Variables 8
2.4 Create Your First Project 8
2.4.1 Start a Project 8
2.4.2 Connect Your Device 8
2.4.3 Configure 8
2.4.4 Build the Project 9
2.4.5 Flash onto the Device 10
2.4.6 Monitor 11
3 U.S. FCC Statement 12
4 Learning Resources 14
4.1 Must-Read Documents 14
4.2 Important Resources 14
Revision History 15
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1 Overview
1 Overview
1.1 Module Overview
ESP8685-WROOM-03 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.
ESP8685-WROOM-03 comes with a PCB antenna.
Table 1: ESP8685WROOM03 Specifications
Categories Parameters Specifications
Wi-Fi Protocols IEEE 802.11 b/g/n (1T1R mode with data rate up to 150 Mbps)
Frequency range 2412 ~2462 MHz
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), USB Seri-
al/JTAG controller, temperature sensor, SAR ADC
Integrated crystal 40 MHz crystal oscillator
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 –40 °C ~+105 °C
Moisture sensitivity level (MSL) Level 3
1.2 Pin Description
GND
3V3 RX
TX
IO9
EN
Keepout Zone Keepout Zone
Pin Layout(Top) Pin Layout(Bottom)
EN
IO1
IO6
IO7 IO3
Pin1
Pin2
Pin3
Pin4
Pin5
3V3
GND
RX
TX
IO5
Pin6 Pin7 Pin8 Pin9
Pin10
IO4Pin11
EPAD
Figure 1: Pin Layout (Top View)
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1 Overview
The module has 11 pins. See pin definitions in Table 2.
Table 2: Pin Definitions
Name No. Type1Function
EN 1 I
High: on, enables the chip.
Low: off, the chip powers off.
Default: internally pulled-up
IO1 2 I/O/T GPIO1, ADC1_CH1, XTAL_32K_N
IO6 3 I/O/T GPIO6, FSPICLK, MTCK, LED PWM
IO7 4 I/O/T GPIO7, FSPID, MTDO, LED PWM
IO3 5 I/O/T GPIO3, ADC1_CH3, LED PWM
3V3 6 P Power supply
GND 7 P Ground
RX 8 I/O/T GPIO20, U0RXD
TX 9 I/O/T GPIO21, U0TXD
IO5 10 I/O/T GPIO5, ADC2_CH0, FSPIWP, MTDI, LED PWM
IO4 11 I/O/T GPIO4, ADC1_CH4, FSPIHD, MTMS, LED PWM
Table 3: Test Point Definitions
Name Type1Function
EN I
High: on, enables the chip.
Low: off, the chip powers off.
Default: internally pulled-up
TX I/O/T GPIO21, U0TXD
RX I/O/T GPIO20, U0RXD
GND P Ground
3V3 P Power supply
IO9 I/O/T GPIO9
1P: power supply; I: input; O: output; T: high impedance.
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2 Get Started on ESP8685-WROOM-03
2 Get Started on ESP8685WROOM03
2.1 What You Need
To develop applications for ESP8685-WROOM-03 module you need:
• 1 x ESP8685-WROOM-03 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.
2.2 Hardware Connection
1. Solder the ESP8685-WROOM-03 module to the RF testing board as shown in Figure 2.
Figure 2: Hardware Connection
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. Then, turn ”ON” the testing board.
6. Download firmware into flash. For details, see the sections below.
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2 Get Started on ESP8685-WROOM-03
7. After download, remove the jumper on IO9 and GND.
8. Power up the RF testing board again. ESP8685-WROOM-03 will switch to working mode. The chip will read
programs from flash upon initialization.
Note:
IO9 is internally logic high. If IO9 is set to pull-up, the Boot mode is selected. If this pin is pull-down or left floating,
the Download mode is selected. For more information on ESP8685-WROOM-03, please refer to ESP8685-WROOM-03
Datasheet.
2.3 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.
2.3.1 Install Prerequisites
To compile with ESP-IDF you need to get the following packages:
• CentOS 7 & 8:
sudo yum -y update && sudo yum install git wget flex bison gperf python3 python3-pip python3-setuptools cmake ninja-build ccache dfu-util libusbx
• Ubuntu and Debian:
sudo apt-get install git wget flex bison gperf python3 python3-pip python3-setuptools cmake ninja-build ccache libffi-dev libssl-dev dfu-util libusb-1.0-0
• Arch:
sudo pacman -S --needed gcc git make flex bison gperf python-pip cmake ninja ccache dfu-util libusb
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.
2.3.2 Get ESPIDF
To build applications for ESP8685-WROOM-03 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’:
mkdir -p ~/esp
cd ~/esp
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.
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2 Get Started on ESP8685-WROOM-03
2.3.3 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.
cd ~/esp/esp-idf
./install.sh
2.3.4 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 ESP8685-WROOM-03 module.
2.4 Create Your First Project
2.4.1 Start a Project
Now you are ready to prepare your application for ESP8685-WROOM-03 module. You can start with get-started/hello_world
project from examples directory in ESP-IDF.
Copy get-started/hello_world to ~/esp directory:
cd ~/esp
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.
2.4.2 Connect Your Device
Now connect your ESP8685-WROOM-03 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:
ls /dev/tty*
Note:
Keep the port name handy as you will need it in the next steps.
2.4.3 Configure
Navigate to your ‘hello_world’ directory from Step 2.4.1. Start a Project, set ESP8685 as the target and run the
project configuration utility ‘menuconfig’.
cd ~/esp/hello_world
idf.py set-target esp8685
idf.py menuconfig
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Setting the target with ‘idf.py set-target esp8685’ 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:
Figure 3: Project Configuration  Home Window
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.
2.4.4 Build the Project
Build the project by running:
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.
$ idf.py build
Running cmake in directory /path/to/hello_world/build
Executing ”cmake -G Ninja --warn-uninitialized /path/to/hello_world”...
Warn about uninitialized values.
-- Found Git: /usr/bin/git (found version ”2.17.0”)
-- Building empty aws_iot component due to configuration
-- Component names: ...
-- Component paths: ...
... (more lines of build system output)
[527/527] Generating hello-world.bin
esptool.py v2.3.1
Project build complete. To flash, run this command:
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2 Get Started on ESP8685-WROOM-03
../../../components/esptool_py/esptool/esptool.py -p (PORT) -b 921600 write_flash --flash_mode dio
--flash_size detect --flash_freq 40m 0x10000 build/hello-world.bin build 0x1000
build/bootloader/bootloader.bin 0x8000 build/partition_table/partition-table.bin
or run ’idf.py -p PORT flash’
If there are no errors, the build will finish by generating the firmware binary .bin file.
2.4.5 Flash onto the Device
Flash the binaries that you just built onto your ESP8685-WROOM-03 module by running:
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.
...
esptool.py --chip esp8685 -p /dev/ttyUSB0 -b 460800 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 80m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x0 bootloader/bootloader.bin 0x10000 hello-world.bin
esptool.py v3.0
Serial port /dev/ttyUSB0
Connecting....
Chip is ESP8685
Features: Wi-Fi
Crystal is 40MHz
MAC: 7c:df:a1:40:02:a4
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Compressed 3072 bytes to 103...
Writing at 0x00008000... (100 %)
Wrote 3072 bytes (103 compressed) at 0x00008000 in 0.0 seconds (effective 4238.1 kbit/s)...
Hash of data verified.
Compressed 18960 bytes to 11311...
Writing at 0x00000000... (100 %)
Wrote 18960 bytes (11311 compressed) at 0x00000000 in 0.3 seconds (effective 584.9 kbit/s)...
Hash of data verified.
Compressed 145520 bytes to 71984...
Writing at 0x00010000... (20 %)
Writing at 0x00014000... (40 %)
Writing at 0x00018000... (60 %)
Writing at 0x0001c000... (80 %)
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2 Get Started on ESP8685-WROOM-03
Writing at 0x00020000... (100 %)
Wrote 145520 bytes (71984 compressed) at 0x00010000 in 2.3 seconds (effective 504.4 kbit/s)...
Hash of data verified.
Leaving...
Hard resetting via RTS pin...
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.
2.4.6 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:
$ idf.py -p /dev/ttyUSB0 monitor
Running idf_monitor in directory [...]/esp/hello_world/build
Executing ”python [...]/esp-idf/tools/idf_monitor.py -b 115200 [...]/esp/hello_world/build/hello-world.elf”...
--- idf_monitor on /dev/ttyUSB0 115200 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
ets Jun 8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
ets Jun 8 2016 00:22:57
...
After startup and diagnostic logs scroll up, you should see “Hello world!” printed out by the application.
...
Hello world!
Restarting in 10 seconds...
This is esp8685 chip with 1 CPU core, WiFi/BLE
Restarting in 9 seconds...
Restarting in 8 seconds...
Restarting in 7 seconds...
To exit IDF monitor use the shortcut Ctrl+].
That’s all what you need to get started with ESP8685-WROOM-03 module! Now you are ready to try some other
examples in ESP-IDF, or go right to developing your own applications.
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3 U.S. FCC Statement
3 U.S. FCC Statement
FCC ID: 2AC7ZESP868503
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.
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.
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 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 transmit-
ter.
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 module can be used to
installation in another host. 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 transmit or antenna. The module
shall be only used with the integral antenna(s) that has been originally tested and certified with this module.
As long as 3 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 requirement with this module installed
(for example, digital device emission, PC peripheral requirements, etc.)
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3 U.S. FCC Statement
Notice:
In the event that these conditions cannot be met (for example certain laptop configuration 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 and circumstance, the OEM integrator will
be responsible for re-evaluating. The end product (including the transmitter) and obtaining a separate FCC authorization.
The final end product must be labeled in a visible area with the following: “Contains Transmitter Module FCC ID:
2AC7ZESP868503 or Contains FCC ID: 2AC7ZESP868503”.
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4 Learning Resources
4 Learning Resources
4.1 MustRead Documents
Please familiarize yourself with the following documents:
•ESP-IDF Programming Guide
Extensive documentation for the ESP-IDF development framework, ranging from hardware guides to API
reference.
•Espressif Products Ordering Information
4.2 Important Resources
Here are the important -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.
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Revision History
Revision History
Date Version Release notes
2021-12-27 V0.1 Preliminary release
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NO WARRANTY IS PROVIDED TO THIS DOCUMENT FOR ITS MERCHANTABILITY, NON-
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Copyright © 2021 Espressif Systems (Shanghai) Co., Ltd. All rights reserved.