Sparkleiot ESP-32S WiFi Module
User Manual | Version: VER:V1.1 | Date: 2018-3-18 | Number: ESP32SCN
Features
SoC Features
- Built-in Tensilica L106 ultra-low power consumption 32-bit CPU, with main frequencies of 80MHz and 160MHz, supporting RTOS.
- Built-in TCP/IP protocol stack.
- Built-in 1 channel 10-bit high precision ADC.
- Interfaces include HSPI, UART, I2C, I2S, IR Remote Control, PWM, GPIO.
- 20µA deep-sleep current, less than 5µA cutoff current.
- 2ms wake-up time.
- 1.0mW consume power (DTIM3 and standby state).
Wi-Fi Features
- Support 802.11 b/g/n/e/i.
- Support three modes: Station, SoftAP, and SoftAP+STA.
- Support Wi-Fi Direct (P2P).
- Support hardware acceleration for CCMP (CBC-MAC, computation mode), TKIP (MIC, RC4), WAPI(SMS4), WEP(RC4), CRC.
- P2P detection, P2P GO mode/GC mode and P2P power management.
- WPA/PA2 PSK and WPS.
- Support 802.11i security: pre-certification and TSN.
- Support 802.11n (2.4 GHz).
- 802.1h/RFC1042 frame encapsulation.
- Support seamless roam.
- Support AT remote upgrade and cloud OTA upgrade.
- Support SmartConfig function for Android and iOS devices.
Module Interface
- 2xUART
- 1xADC
- 1xEn
- 1xWakeup pin
- 1xHSPI
- 1xI2C
- 1xI2S
- 11xGPIOs
- 4M SPI Flash
Working temperature: -40°C to 105°C
Module size: 16mm x 24mm
Applications
- Serial transparent transmission.
- WiFi prober.
- Smart power plug/Smart LED light.
- Mesh networks.
- Sensor networks.
- Wireless location recognition; Wireless location system beacon.
- Industrial wireless control.
Module Structure
A block diagram illustrating the ESP-32S module's internal architecture. It shows connections to a 2.4G WiFi antenna, RISC-V 32 CPU, 160MHz CPU, 4MB Flash, 400K SRAM, 483K ROM, DMA, MESH, TWAI, SPI, UART, I2C, HSPI, USB, PWM, ADC, and a 3.3V power input.
Update Record
| Date | Version | Update |
|---|---|---|
| 2017-3-14 | V1.0 | Initial version |
| 2017-3-18 | V1.1 | Add system design |
Introduction
The ESP-32S WiFi module is manufactured using the high-performance ESP8266 chip. This compact module features an enhanced Tensilica's L106 diamond series 32-bit CPU with SRAM. The ESP8266 chip provides full Wi-Fi functionality, allowing the module to operate independently or as a slave device with another host CPU. Its built-in high-speed buffer enhances system performance and optimizes storage. The ESP-32S module can also function as a Wi-Fi adapter via SPI/SDIO or I2C/UART interfaces for integration into other MCU designs. It supports the standard IEEE802.11 b/g/n/e/i protocol and a complete TCP/IP stack, enabling users to add Wi-Fi capabilities to devices or use it as an independent network controller, offering versatile solutions at a competitive price.
Technical Parameters
ESP-32S Parameters
| Types | Items | Parameters |
|---|---|---|
| Wi-Fi | Frequency | 2.4G~2.5G (2400M~2483.5M) |
| Transmit power | 802.11b: +15 dBm 802.11g: +14 dBm 802.11n: +14 dBm | |
| Receiver sensitivity | 802.11b: -91 dBm (11Mbps) 802.11g: -75 dBm (54Mbps) 802.11n: -72 dBm (MCS7) | |
| Antenna | PCB antenna / U.F.L antenna | |
| CPU | Tensilica L106 32 bit MCU | |
| Hardware | Interface | UART/SDIO/SPI/I2C/I2S/IR control |
| GPIO | GPIO/ADC/PWM/SPI/I2C/I2S | |
| Working voltage | 2.5V ~ 3.6V | |
| Working current | Average current: 80 mA, Peak current: >200mA | |
| Working temperature | -40°C ~ 105°C | |
| Environment temperature | -40°C ~ 105°C | |
| Software Types | Shape | 16*24*3mm |
| Wi-Fi working mode | Station/SoftAP/SoftAP+Station | |
| Security mode | WPA/WPA2 | |
| Encryption type | WEP/TKIP/AES | |
| Update firmware | UART Download/OTA | |
| Software develop | Non-RTOS/RTOS/Arduino IDE etc. | |
| Network protocol | IPv4, TCP/UDP/HTTP/FTP/MQTT |
Interface Definition
The ESP-32S module interface definition is detailed below. A pinout diagram shows the physical arrangement of pins and their functions.
A textual description of the pinout diagram: The diagram displays the ESP-32S module with pins numbered 1 through 38. Pins are grouped and labeled with their corresponding functions, including GND, 3V3, EN, SENSOR_VP, SENSOR_VN, various GPIO pins (e.g., IO34, IO35, IO32, IO33, IO25, IO26, IO27, IO14, IO12, IO13, IO15, IO2, IO0, IO4, IO16, IO17, IO5, IO18, IO19, IO21, IO22, IO23), SPI interfaces (VSPI, HSPI), UART interfaces (U0RXD, U0TXD, U1RXD, U1TXD, U2RTS, U2TXD), I2C interfaces, ADC channels, PWM, RTC_GPIO, TOUCH pins, EMAC signals, and SD card interfaces.
Working mode and pin function are shown in Table 2.1 and Table 2.2.
Table 2.1 Working Mode
| Mode | GPIO |
|---|---|
| UART Download Mode | Low |
| Flash Boot Mode | High |
Table 2.2 Pin Function Definition
| Name | Serial number | Feature |
|---|---|---|
| GND | 1 | Ground connection |
| 3V3 | 2 | Power supply |
| EN | 3 | Enable chip, high level valid. |
| SENSOR_V P | 4 | GPI36, SENSOR_VP, ADC_H, ADC1_CH0, RTC_GPIO0 |
| SENSOR_V N | 5 | GPI39, SENSOR_VN, ADC1_CH3, ADC_H, RTC_GPIO3 |
| IO34 | 6 | GPI34, ADC1_CH6, RTC_GPIO4 |
| IO35 | 7 | GPI35, ADC1_CH7, RTC_GPIO5 |
| IO32 | 8 | GPIO32, XTAL_32K_P (32.768 kHz crystal oscillator input), ADC1_CH4, TOUCH9, RTC_GPIO9 |
| IO33 | 9 | GPIO33, XTAL_32K_N (32.768 kHz crystal oscillator output), ADC1_CH5, TOUCH8, RTC_GPIO8 |
| IO25 | 10 | GPIO25, DAC_1, ADC2_CH8, RTC_GPIO6, EMAC_RXD0 |
| IO26 | 11 | GPIO26, DAC_2, ADC2_CH9, RTC_GPIO7, EMAC_RXD1 |
| IO27 | 12 | GPIO27, ADC2_CH7, TOUCH7, RTC_GPIO17, EMAC_RX_DV |
| IO14 | 13 | GPIO14, ADC2_CH6, TOUCH6, RTC_GPIO16, MTMS, HSPICLK, HS2_CLK, SD_CLK, EMAC_TXD2 |
| IO12 | 14 | GPIO12, ADC2_CH5, TOUCH5, RTC_GPIO15, MTDI, HSPIQ, HS2_DATA2, SD_DATA2, EMAC_TXD3 |
| GND | 15 | Ground connection |
| IO13 | 16 | GPIO13, ADC2_CH4, TOUCH4, RTC_GPIO14, MTCK, HSPID, HS2_DATA3, SD_DATA3, EMAC_RX_ER |
| SHD/SD2 | 17 | GPIO9, SD_DATA2, SPIHD, HS1_DATA2, U1RXD |
| SWP/SD3 | 18 | GPIO10, SD_DATA3, SPIWP, HS1_DATA3, U1TXD |
| SCS/CMD | 19 | GPIO11, SD_CMD, SPICS0, HS1_CMD, U1RTS |
| SCK/CLK | 20 | GPIO6, SD_CLK, SPICLK, HS1_CLK, U1CTS |
| SDO/SD0 | 21 | GPIO7, SD_DATA0, SPIQ, HS1_DATA0, U2RTS |
| SDI/SD1 | 22 | GPIO8, SD_DATA1, SPID, HS1_DATA1, U2CTS |
| IO15 | 23 | GPIO15, ADC2_CH3, TOUCH3, MTDO, HSPICS0, RTC_GPIO13, HS2_CMD, SD_CMD, EMAC_RXD3 |
| IO2 | 24 | GPIO2, ADC2_CH2, TOUCH2, RTC_GPIO12, HSPIWP, HS2_DATA0, SD_DATA (internal 12K resistance ground) |
| IO0 | 25 | GPIO0, ADC2_CH1, TOUCH1, RTC_GPIO11, CLK_OUT1, EMAC_TX_CLK |
| IO4 | 26 | GPIO4, ADC2_CH0, TOUCH0, RTC_GPIO10, HSPIHD, HS2_DATA1, SD_DATA1, EMAC_TX_ER |
| IO16 | 27 | GPIO16, HS1_DATA4, U2RXD, EMAC_CLK_OUT |
| IO17 | 28 | GPIO17, HS1_DATA5, U2TXD, EMAC_CLK_OUT_180 |
| IO5 | 29 | GPIO5, VSPICS0, HS1_DATA6, EMAC_RX_CLK |
| IO18 | 30 | GPIO18, VSPICLK, HS1_DATA7 |
| IO19 | 31 | GPIO19, VSPIQ, U0CTS, EMAC_TXD0 |
| NC | 32 | - |
| IO21 | 33 | GPIO21, VSPIHD, EMAC_TX_EN |
| RXD0 | 34 | GPIO3, U0RXD, CLK_OUT2 |
| TXD0 | 35 | GPIO1, U0TXD, CLK_OUT3, EMAC_RXD2 |
| IO22 | 36 | GPIO22, VSPIWP, U0RTS, EMAC_TXD1 |
| IO23 | 37 | GPIO23, VSPID, HS1_STROBE |
| GND | 38 | Ground connection |
Shape and Size
The ESP-32S module has dimensions of 16mm x 24mm. The Flash memory capacity is 32 Mbits (4M Bytes).
A textual description of the diagrams: (a) Vertical View: Shows the physical layout of the module's pads and antenna area. Dimensions are provided in millimeters, indicating pad sizes, distances between pads, and overall module dimensions. (b) Side View: Illustrates the module's profile, showing its height and pad placement. Table 3.1 provides specific measurements: Length 25.5 mm, Width 18 mm, Height 3 mm, PAD Size (bottom) 0.45 mm x 0.9 mm, Distance between Pins 0.8 ± 0.1 mm.
Electronical Characteristics
Table 4.1 Electronical Characteristics
| Parameters | Condition | Min | Classical | Max | Unite |
|---|---|---|---|---|---|
| Store Temperature | -40 | Normal | 125 | °C | |
| Sold Temperature | IPC/JEDEC J-STD-020 | 260 | °C | ||
| Working Voltage | 2.5 | 3.3 | 3.6 | V | |
| I/O | VIL/VIH | -0.3/0.75VIO | 0.25VIO/3.6 | VIO | |
| VOL/VOH | N/0.8VIO | 0.1VIO/N | |||
| IMAX | 12 | mA | |||
| Electrostatic release quantity (Human model) | TAMB=25°C | 2 | KV | ||
| Electrostatic release quantity (Human model) | TAMB=25°C | 0.5 | KV |
Power Consumption
Table 5.1 Power Consumption
| Parameters | Min | Classical | Max | Unit |
|---|---|---|---|---|
| Tx802.11b, CCK 11Mbps, POUT=+17dBm | - | 170 | - | mA |
| Tx802.11g, OFDM 54 Mbps, POUT =+15dBm | - | 140 | - | mA |
| Tx802.11n,MCS7,POUT =+13dBm | - | 120 | - | mA |
| Rx 802.11b, 1024 Bytes, -80dBm | - | 50 | - | mA |
| Rx 802.11g, 1024 Bytes, -70dBm | - | 56 | - | mA |
| Rx 802.11n, 1024 Bytes, -65dBm | - | 56 | - | mA |
| Modem-sleep | - | 15 | - | mA |
| Light-sleep | - | 0.9 | - | mA |
| Deep-sleep | - | 20 | µA |
Note:
- Modem-Sleep mode: Suitable when the CPU is active (e.g., PWM, I2S). The Wi-Fi modem can be turned off to save power when connected but idle. For example, at DTIM3 status, sleeping for 300ms allows wake-up within 3ms to receive beacon packets, with a current of 15mA.
- Light-Sleep mode: Used when the CPU can be temporarily stopped (e.g., Wi-Fi Switch). If Wi-Fi is connected without data transmission (e.g., U-APSD), the module can disable the Wi-Fi modem and stop the CPU. At DTIM3, sleeping for 300ms and waking up every 3ms for beacon packets results in an average current of approximately 0.9mA.
- Deep-Sleep mode: Applied when Wi-Fi connection is not continuous. Data packets are sent infrequently (e.g., every 100s). Connecting to an AP after 300s takes 0.3s-1s, with a much lower average current (<1mA).
Wi-Fi RF Characteristics
Data is obtained at 3.3V and 1.1V in an indoor temperature environment.
Table 6.1 Wi-Fi RF Characteristics
| Parameters | Min | Classical | Max | Unite |
|---|---|---|---|---|
| Input frequency | 2412 | 2484 | MHz | |
| Input impedance | 50 | Ω | ||
| Input reflection | -10 | dB | ||
| At 72.2Mbps, output power consumption for PA | 15.5 | 16.5 | 17.5 | dBm |
| At 11b mode, output power consumption for PA | 19.5 | 20.5 | 21.5 | dBm |
| Sensibility | ||||
| DSSS, 1Mbps | -98 | dBm | ||
| CCK11, Mbps | -91 | dBm | ||
| 6Mbps(1/2 BPSK) | -93 | dBm | ||
| 54Mbps(3/4 64-QAM) | -75 | dBm | ||
| HT20, MCS7(65 Mbps, 72.2 Mbps) | -72 | dBm | ||
| Adjacent Inhibition | ||||
| OFDM, 6Mbps | 37 | dB | ||
| OFDM, 54Mbps | 21 | dB | ||
| HT20, MCS0 | 37 | dB | ||
| HT20, MCS7 | 20 | dB |
Recommended Sold Temperature Curve
A textual description of the soldering temperature curve diagram: The graph illustrates the recommended temperature profile for soldering the module. It shows temperature on the Y-axis and time on the X-axis. Key stages include: a 25°C starting point, a preheat phase from 150°C to 200°C over 60-120 seconds with a ramp-up rate of max 2°C/sec; a peak phase reaching 245+0/-5°C; and a ramp-down phase with a rate of max 2.5°C/sec. The slope from 217°C to peak is 1~2°C/sec max. The ramp-down phase lasts 40-60 seconds.
Module Schematic
A textual description of the module schematic diagram: The diagram shows the internal circuitry of the ESP-32S module, including the ESP32 chip, power supply connections (VDD33, GND), boot option circuitry (EN, GPIO0, resistors R7, R8, transistors S8050), and various interface pins connected to external components or the main board. It details connections for UART download, JTAG, and general GPIO usage.
Recommended PCB Design
The ESP-32S Wi-Fi module can be integrated directly onto a PCB. For optimal RF performance, careful placement is crucial. Three recommended integration methods are described:
- Solution 1 (Optical): The Wi-Fi module is placed on one side of the board with its antenna fully exposed. No metal materials (wires, casings, plates) should be present around the antenna.
- Solution 2 (Suboptical): The module is placed on one side of the board, and the area beneath the antenna is hollowed out. A gap of at least 5 mm should be maintained around the antenna, free from metal materials.
- Solution 3: The module is placed on one side of the board, and the PCB area directly under the antenna is kept empty, with no copper traces or planes.
A textual description of the diagrams: Figures 10.1, 10.2, and 10.3 visually represent these three PCB design solutions, showing the ESP-32S module (XH-C2F) on a main board with different antenna clearance and PCB area configurations.
Peripheral Design Suggestion
The Wi-Fi module integrates high-speed GPIO and peripheral interfaces, which can generate switching noise. For applications requiring stringent power consumption and EMI characteristics, it is recommended to connect a serial 10-100 ohm resistance. This resistor helps suppress overshoot during power supply switching, smooths signals, and prevents electrostatic discharge (ESD).
Notes
The following notes provide additional operational details:
- Working voltage for the module is DC 3.3V.
- Maximum current from the module's IO pins is 12mA.
- The RST Pin is enabled when at a low level; the EN pin is enabled when at a high level.
- For Wi-Fi module update mode, GPIO0 should be at a low level, followed by a module reset. For Wi-Fi working mode, GPIO0 should be at a high level, followed by a reset.
- When connecting to another MCU, the Wi-Fi module's RXD should be connected to the other MCU's TXD, and the module's TXD to the other MCU's RXD.
Disclaimer and Copyright Notice
The information in this document, including URLs, is subject to change without prior notice. Documents are provided without warranty, including merchantability or suitability for any purpose. Sparkleiot Technology Co., Ltd. disclaims responsibility for any infringement of patent rights arising from the use of this information. Wi-Fi alliance marks are owned by the Wi-Fi alliance. All other brand names and trademarks are the property of their respective owners.
Shenzhen Sparkleiot Technology Co., Ltd. is a national-level high-tech enterprise specializing in R&D, production, and sales of smart home and IoT products. Established in 2014, the company focuses on technological innovation and has launched cost-effective 2.4G WiFi modules. In 2018, it expanded into the smart home lighting industry, with products exported globally and receiving positive customer feedback.
FCC Statement
This device complies with Part 15 of the FCC Rules. Operation is subject to two conditions: (1) it must not cause harmful interference, and (2) it must accept any received interference, including interference that may cause undesired operation. Unauthorized changes or modifications could void the user's authority to operate the equipment.
This equipment has been tested and found to comply with the limits for a Class B digital device, as per Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in residential installations. The equipment generates, uses, and can radiate radio frequency energy. If not installed and used according to instructions, it may cause harmful interference to radio communications. However, interference is not guaranteed to be absent in all installations. If interference occurs, users are encouraged to try correcting it by:
- Reorienting or relocating the receiving antenna.
- Increasing the separation between the equipment and receiver.
- Connecting the equipment to a circuit different from that of the receiver.
- Consulting a dealer or an experienced radio/TV technician.
Important Note: Radiation Exposure Statement
This equipment complies with FCC radiation exposure limits for an uncontrolled environment. It should be installed and operated with a minimum distance of 20cm between the radiator and the user's body. The transmitter must not be co-located or operated in conjunction with any other antenna or transmitter. The Country Code selection feature must be disabled for products marketed in the US/Canada.
This device is intended for OEM integrators under specific conditions:
- The antenna must be installed such that a 20 cm distance is maintained between the antenna and users.
- The transmitter module may not be co-located with any other transmitter or antenna.
- For products marketed in the US, OEM must limit the operation channels to CH1-CH11 for the 2.4G band using the supplied firmware programming tool. OEMs shall not provide end-users with tools or information for changing the Regulatory Domain.
Meeting these conditions means further transmitter testing is not required. However, the OEM integrator remains responsible for testing their end-product for any additional compliance requirements with this module installed.
Important Note:
If the above conditions cannot be met (e.g., due to laptop configurations or co-location with other transmitters), the FCC authorization becomes invalid, and the FCC ID cannot be used on the final product. In such cases, the OEM integrator must re-evaluate the end product and obtain separate FCC authorization.
End Product Labeling
The final end product must be labeled visibly with "Contains FCC ID: 2BCLP-ESP-32S".
Manual Information to the End User
OEM integrators must not provide end-users with instructions on installing or removing this RF module in the end product's user manual. The end-user manual must include all required regulatory information and warnings present in this document.
Integration Instructions for Host Product Manufacturers
2.2 List of applicable FCC rules
CFR 47 FCC PART 15 SUBPART C has been investigated and is applicable to the modular transmitter.
2.3 Specific operational use conditions
This module is a stand-alone modular transmitter. If the end product involves multiple simultaneously transmitting conditions or different operational conditions for a stand-alone modular transmitter within a host, the host manufacturer must consult with the module manufacturer for the installation method in the end system.
2.4 Limited module procedures
Not applicable.
2.5 Trace antenna designs
Not applicable.
2.6 RF exposure considerations
This equipment complies with FCC radiation exposure limits for an uncontrolled environment. It should be installed and operated with a minimum distance of 20cm between the radiator and the user's body.
2.7 Antennas
This radio transmitter (FCC ID: 2BCLP-ESP-32S) has been approved by the Federal Communications Commission to operate with the antenna types listed below, with the maximum permissible gain indicated. Antenna types not included in this list that have a gain greater than the maximum gain indicated are strictly prohibited for use with this device.
| Antenna No. | Model No. of antenna: | Type of antenna: | Gain of the antenna (Max.) | Frequency range: |
|---|---|---|---|---|
| 2.4GWiFi | / | PCB Antenna | 0.75dBi for 2412-2462MHz; |
2.8 Label and compliance information
The final end product must be labeled in a visible area with: "Contains FCC ID: 2BCLP-ESP-32S".
2.9 Information on test modes and additional testing requirements
Host manufacturers are strongly recommended to confirm compliance with FCC requirements for the transmitter when the module is installed in the host.
2.10 Additional testing, Part 15 Subpart B disclaimer
The host manufacturer is responsible for ensuring the compliance of the host system, with the module installed, with all other applicable requirements for the system, such as Part 15 B.
