ESPRESSIF ESP32-WROOM-32E 8M 64Mbit Flash WiFi Bluetooth Module

ESPRESSIF ESP32-WROOM-32E 8M 64Mbit Flash WiFi Bluetooth Module

About This Document

This document provides the specifications for the ESP32-WROOM-32E modules with PCB antenna.

Revision History

For revision history of this document, please refer to the last page

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Information in this document, including URL references, is subject to change without notice. THIS DOCUMENT IS PROVIDED AS IS WITH NO WARRANTIES WHATSOEVER, INCLUDING ANY WARRANTY OF MERCHANTABIL-ITY, NON-INFRINGEMENT, FITNESS FOR ANY PARTICULAR PURPOSE, OR 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 © 2019 Espressif Inc. All rights reserved.

Overview

ESP32 -WROOM -32E is a powerful, generic WiFi -BT -BLE MCU module that targets a wide variety of applications, ranging from low -power sensor networks to the most demanding tasks, such as voice encoding, music streaming and MP3 decoding.

This is a SMD Module with 2.4 GHz PCB antenna on board. It reserves π tuning circuit for antenna
impedance matching. It is with all GPIOs on the pin -out except the ones already used for connecting flash. The Module’s working voltage can be range from 3.0 V to 3.6 V. Frequency range is 2400 MHz to 2483.5 MHz. External 40 MHz as clock source for system. There is also a 4 MB SPI flash for storing user programs and data.

The ordering information of ESP32 -WROOM -32E is listed as follows:
Table 1: ESP32 -WROOM -32E Ordering Information

ModuleChip embeddedFlashPSRAMModule dimensions (mm)
ESP32-WROOM-32EESP32-D0WD-V34 MB 1/(18.00 ± 0.10) X (25.50 ± 0.10) X
(3.10 ± 0.10) mm (including metallic shield)
Notes:
  1. ESP32-WROOM-32E (PCB) with 8 MB flash or 16 MB flash is available for custom order.
  2. For detailed ordering information, please see Espressif Product Ordering Information.
  3. For dimensions of the IPEX connector, please see Chapter 10.

At the core of the module is the ESP32 -D0WD -V3 chip*. The chip embedded is designed to be scalable and adaptive. There are two CPU cores that can be individually controlled, and the CPU clock frequency is adjustable from 80 MHz to 240 MHz. The user may also power off the CPU and make use of the low -power co-processor to constantly monitor the

Note:
  • For details on the part numbers of the ESP32 family of chips, please refer to the document ESP32 Datasheet

The integration of Bluetooth, Bluetooth LE and Wi -Fi ensures that a wide range of applications can be targeted, and that the module is all -around: using Wi -Fi allows a large physical range and direct connection to the Internet through a Wi -Fi router, while using Bluetooth allows the user to conveniently connect to the phone or broadcast low energy beacons for its detection. The sleep current of the ESP32 chip is less than 5 A, making it suitable for battery powered and wearable electronics applications. The module supports a data rate of up to 150 Mbps, As such the module does offer industry-leading specifications and the best performance for electronic integration, range, power consumption, and connectivity.

The operating system chosen for ESP32 is freeRTOS with LwIP; TLS 1.2 with hardware acceleration is built in as well. Secure (encrypted) over the air (OTA) upgrade is also supported, so that users can upgrade their products even after their release, at minimum cost and effort. Table 2 provides the specifications of ESP32 -WROOM -32E.

Table 2: ESP32-WROOM-32E Specifications

CategoriesItemsSpecifications
TestReliablityHTOL/HTSL/uHAST/TCT/ESD
Wi-FiProtocols802.11 b/g/n20/n40
A-MPDU and A-MSDU aggregation and 0.4 s guard interval support
Frequency range2.412 GHz ~ 2.462GHz
BluetoothProtocolsBluetooth v4.2 BR/EDR and BLE specification
RadioNZIF receiver with –97 dBm sensitivity
Class-1, class-2 and class-3 transmitter
AFH
AudioCVSD and SBC
HardwareModule interfacesSD card, UART, SPI, SDIO, I2C, LED PWM, Motor PWM, I2S, IR, pulse counter, GPIO, capacitive touch sensor, ADC, DAC
On-chip sensorHall sensor
Integrated crystal40 MHz crystal
Integrated SPI flash4 MB
Integrated PSRAM
Operating voltage/Power supply3.0 V ~ 3.6 V
Minimum current delivered by power supply500 mA
Recommended operating temperature range–40 °C ~ 85 °C
Package size(18.00±0.10) mm × (31.40±0.10) mm × (3.30±0.10) mm
Moisture sensitivity level (MSL)Level 3

Pin Definitions

Pin Layout

Figure 1: Pin Layout of ESP32-WROOM-32E (Top View)
Pin Layout

Pin Description

ESP32-WROOM-32E has 38 pins. See pin definitions in Table 3

Table 3: Pin Definitions

NameNo.TypeFunction
GND1PGround
3V32PPower supply
EN3IModule-enable signal. Active high.
SENSOR_VP4IGPIO36, ADC1_CH0, RTC_GPIO0
SENSOR_VN5IGPIO39, ADC1_CH3, RTC_GPIO3
IO346IGPIO34, ADC1_CH6, RTC_GPIO4
IO357IGPIO35, ADC1_CH7, RTC_GPIO5
IO328I/OGPIO32, XTAL_32K_P (32.768 kHz crystal oscillator input), ADC1_CH4, TOUCH9, RTC_GPIO9
IO339I/OGPIO33, XTAL_32K_N (32.768 kHz crystal oscillator output), ADC1_CH5, TOUCH8, RTC_GPIO8
IO2510I/OGPIO25, DAC_1, ADC2_CH8, RTC_GPIO6, EMAC_RXD0
IO2611I/OGPIO26, DAC_2, ADC2_CH9, RTC_GPIO7, EMAC_RXD1
IO2712I/OGPIO27, ADC2_CH7, TOUCH7, RTC_GPIO17, EMAC_RX_DV
IO1413I/OGPIO14, ADC2_CH6, TOUCH6, RTC_GPIO16, MTMS, HSPICLK, HS2_CLK, SD_CLK, EMAC_TXD2
IO1214I/OGPIO12, ADC2_CH5, TOUCH5, RTC_GPIO15, MTDI, HSPIQ,

HS2_DATA2, SD_DATA2, EMAC_TXD3

GND15PGround
IO1316I/OGPIO13, ADC2_CH4, TOUCH4, RTC_GPIO14, MTCK, HSPID, HS2_DATA3, SD_DATA3, EMAC_RX_ER
NC17
NC18
NC19
NC20
NC21
NC22
IO1523I/OGPIO15, ADC2_CH3, TOUCH3, MTDO, HSPICS0, RTC_GPIO13, HS2_CMD, SD_CMD, EMAC_RXD3
IO224I/OGPIO2, ADC2_CH2, TOUCH2, RTC_GPIO12, HSPIWP, HS2_DATA0, SD_DATA0
IO025I/OGPIO0, ADC2_CH1, TOUCH1, RTC_GPIO11, CLK_OUT1, EMAC_TX_CLK
IO426I/OGPIO4, ADC2_CH0, TOUCH0, RTC_GPIO10, HSPIHD, HS2_DATA1, SD_DATA1, EMAC_TX_ER
IO1627I/OGPIO16, HS1_DATA4, U2RXD, EMAC_CLK_OUT
IO1728I/OGPIO17, HS1_DATA5, U2TXD, EMAC_CLK_OUT_180 –
IO529I/OGPIO5, VSPICS0, HS1_DATA6, EMAC_RX_CLK
IO1830I/OGPIO18, VSPICLK, HS1_DATA7
IO1931I/OGPIO19, VSPIQ, U0CTS, EMAC_TXD0
NC32
IO2133I/OGPIO21, VSPIHD, EMAC_TX_EN
RXD034I/OGPIO3, U0RXD, CLK_OUT2
TXD035I/OGPIO1, U0TXD, CLK_OUT3, EMAC_RXD2
IO2236I/OGPIO22, VSPIWP, U0RTS, EMAC_TXD1
IO2337I/OGPIO23, VSPID, HS1_STROBE
GND38PGround
Notice:
  • GPIO6 to GPIO11 are connected to the SPI flash integrated on the module and are not connected out.
    .
Strapping Pins

ESP32 has five strapping pins, which can be seen in Chapter 6 Schematics:

  • MTDI
  • GPIO0
  • GPIO2
  • MTDO
  • GPIO5

Software can read he values of these five bits from register ”GPIO_STRAPPING”.

During the chip’s system reset release (power -on -reset, RTC watchdog reset and brownout reset), the latches of the strapping pins sample the voltage level as strapping bits of ”0” or ”1”, and hold these bits until the chip is powered down or shut down. The strapping bits configure the device’s boot mode, the operating voltage of VDD_SDIO and other initial system settings.

Each strapping pin is connected to its internal pull-up/pull-down during the chip reset. Consequently, if a strapping pin is unconnected or the connected external circuit is high -impedance, the internal weak pull -up/pull – down will determine the default input level of the strapping pins.

To change the strapping bit values, users can apply the external pull -down/pull-up resistances, or use the host MCU’s GPIOs to control the voltage level of these pins when powering on ESP32.

After reset release, the strapping pins work as normal-function pins.

Refer to Table 4 for a detailed boot-mode configuration by strapping pins.

Table 4: Strapping Pins

Voltage of Internal LDO
(VDD_SDIO)

PinDefault3.3 V1.8 V
MTDIPull-down01

Booting Mode

PinDefaultSPI BootDownload Boot
GPIO0Pull-up10
GPIO2Pull-downDon’t-care0

Enabling/Disabling Debugging Log Print over U0TXD During Booting

PinDefaultU0TXD ActiveU0TXD Silent
MTDOPull-up10

Timing of SDIO Slave

PinDefaultFalling-edge Sampling
Falling-edge Output
Falling-edge Sampling
Rising-edge Output
Rising-edge Sampling

Falling-edge Output

Rising-edge Sampling

Rising-edge Output

MTDOPull-up0011
GPIO5Pull-up0101
Note:
  • Firmware can configure register bits to change the settings of ”Voltage of Internal LDO (VDD_SDIO)” and ”Timing of SDIO Slave” after booting.
  • Internal pull-up resistor (R9) for MTDI is not populated in the module, as the flash and SRAM in ESP32-WROOM-32E only support a power voltage of 3.3 V

Functional Description

This chapter describes the modules and functions integrated in ESP32-WROOM-32E.

CPU and Internal Memory

ESP32-D0WD-V3 contains two low-power Xtensa ® 32 -bit LX6 microprocessors. The internal memory includes:

  • 448 KB of ROM for booting and core functions.
  • 520 KB of on-chip SRAM for data and instructions.
  • 8 KB of SRAM in RTC, which is called RTC FAST Memory and can be used for data storage; it is accessed by the main CPU during RTC Boot from the Deep-sleep mode.
  • 8 KB of SRAM in RTC, which is called RTC SLOW Memory and can be accessed by the co-processor during the Deep-sleep mode.
  • 1 Kbit of eFuse: 256 bits are used for the system (MAC address and chip configuration) and the remaining 768 bits are reserved for customer applications, including flash-encryption and chip-ID.
External Flash and SRAM

ESP32 supports multiple external QSPI flash and SRAM chips. More details can be found in Chapter SPI in the ESP32 Technical Reference Manual. ESP32 also supports hardware encryption/decryption based on AES to pro-tect developers’ programs and data in flash.

ESP32 can access the external QSPI flash and SRAM through high-speed caches.

  • The external flash can be mapped into CPU instruction memory space and read-only memory space simul-taneously.
    • When external flash is mapped into CPU instruction memory space, up to 11 MB + 248 KB can be mapped at a time. Note that if more than 3 MB + 248 KB are mapped, cache performance will be reduced due to speculative reads by the CPU.
    • When external flash is mapped into read-only data memory space, up to 4 MB can be mapped at a time. 8-bit, 16-bit and 32-bit reads are supported.
  • External SRAM can be mapped into CPU data memory space. Up to 4 MB can be mapped at a time. 8-bit, 16-bit and 32-bit reads and writes are supported.

ESP32-WROOM-32E integrates a 4 MB SPI flash more memory space.

Crystal Oscillators

The module uses a 40-MHz crystal oscillator.

RTC and Low-Power Management

With the use of advanced power-management technologies, ESP32 can switch between different power modes. For details on ESP32’s power consumption in different power modes, please refer to section ”RTC and Low-Power Management” in ESP32 User Manual.

Peripherals and Sensors

Please refer to Section Peripherals and Sensors in ESP32 User Manual.

Note:
External connections can be made to any GPIO except for GPIOs in the range 6-11, 16, or 17. GPIOs 6-11 are connected to the module’s integrated SPI flash. For details, please see Section 6 Schematics

Electrical Characteristics

Absolute Maximum Ratings

Stresses beyond the absolute maximum ratings listed in the table below may cause permanent damage to the device. These are stress ratings only, and do not refer to the functional operation of the device that should follow the recommended operating conditions.

Table 5: Absolute Maximum Ratings

  1. The module worked properly after a 24-hour test in ambient temperature at 25 °C, and the IOs in three domains (VDD3P3_RTC, VDD3P3_CPU, VDD_SDIO) output high logic level to ground.
  2. Please see Appendix IO_MUX of ESP32 Datasheet for IO’s power domain.
Recommended Operating Condition

Table 6: Recommended Operating Conditions

SymbolParameterMinTypicalMaxUnit
VDD33Power supply voltage3.03.33.6V
I

V DD

Current delivered by external power supply0.5A
TOperating temperature–4085°C
DC Characteristics (3.3 V, 25 °C)

Table 7: DC Characteristics (3.3 V, 25 °C)

SymbolParameterMinTypeMaxUnit
C INPin capacitance2pF
V IHHigh-level input voltage0.75×VDD1VDD1+0.3V
V ILLow-level input voltage–0.30.25×VDD1V
I IHHigh-level input current50nA
I ILLow-level input current50nA
V OHHigh-level output voltage0.8×VDD1V
V OLLow-level output voltage0.1×VDD1V
I OHHigh-level source current (VDD1 = 3.3 V, VOH >= 2.64 V, output drive strength set to the maximum)VDD3P3_CPU power domain 1; 240mA
VDD3P3_RTC power domain 1; 240mA
VDD_SDIO power domain 1; 320mA
I OLLow-level sink current (VDD1 = 3.3 V, VOL = 0.495 V, output drive strength set to the maximum)28mA
R P UResistance of internal pull-up resistor45kΩ
R P DResistance of internal pull-down resistor45kΩ
V IL_nRSTLow-level input voltage of CHIP_PU to power off the chip0.6V

Notes:

  1. Please see Appendix IO_MUX of ESP32 Datasheet for IO’s power domain. VDD is the I/O voltage for a particular power domain of pins.
  2. For VDD3P3_CPU and VDD3P3_RTC power domain, per-pin current sourced in the same domain is gradually reduced from around 40 mA to around 29 mA, VOH>=2.64 V, as the number of current-source pins increases.
  3. Pins occupied by flash and/or PSRAM in the VDD_SDIO power domain were excluded from the test.
Wi-Fi Radio

Table 8: Wi-Fi Radio Characteristics

ParameterConditionMinTypicalMaxU      nit
Operating frequency range note124122462MHz
RF Power

802.11b:26dBm
802.11g:25.42dBm
802.11n20:25.48dBm
802.11n40:25.78dBm

dBm
Sensitivity11b, 1 Mbps–98dBm
11b, 11 Mbps–89dBm
11g, 6 Mbps–92dBm
11g, 54 Mbps–74dBm
11n, HT20, MCS0–91dBm
11n, HT20, MCS7–71dBm
11n, HT40, MCS0–89dBm
11n, HT40, MCS7–69dBm
Adjacent channel rejection11g, 6 Mbps31dB
11g, 54 Mbps14dB
11n, HT20, MCS031dB
11n, HT20, MCS713dB
  1. Device should operate in the frequency range allocated by regional regulatory authorities. Target operating frequency range is configurable by software.
  2. Target TX power is configurable based on device or certification requirements.
Bluetooth/BLE Radio

Receiver

Table 9: Receiver Characteristics – Bluetooth/BLE

ParameterConditionsMinTypeMaxUnit
Sensitivity @30.8% PER–97dBm
Maximum received signal @30.8% PER0dBm
Co-channel C/I+10dB
Adjacent channel selectivity C/IF = F0 + 1 MHz–5dB
F = F0 – 1 MHz–5dB
F = F0 + 2 MHz–25dB
F = F0 – 2 MHz–35dB
F = F0 + 3 MHz–25dB
F = F0 – 3 MHz–45dB
Out-of-band blocking performance30 MHz ~ 2000 MHz–10dBm
2000 MHz ~ 2400 MHz–27dBm
2500 MHz ~ 3000 MHz–27dBm
3000 MHz ~ 12.5 GHz–10dBm
Intermodulation–36dBm
Transmitter

Table 10: Transmitter Characteristics – Bluetooth/BLE

ParameterConditionsMinTypeMaxUnit
RF Frequency24022480MHz
Gain control step3dBm
RF power control range–12+10dBm
Adjacent channel transmit powerF = F0 ± 2 MHz–52dBm
F = F0 ± 3 MHz–58dBm
F = F0 ± > 3 MHz–60dBm
f1avg265kHz
f2

max

247kHz
f2avg/∆ f1avg–0.92
ICFT–10kHz
Drift rate0.7kHz/50 s
Drift2kHz
Reflow Profile

Figure2:ReflowProfile

Reflow Profile

Ramp -up zone — Temp.: <150°C Time: 60 ~ 90s Ramp -up rate: 1 ~ 3°C/s
Preheating zone — Temp.: 150 ~ 200°C Time: 60 ~ 120s Ramp -up rate: 0.3 ~ 0.8°C/s
Reflow zone — Temp.: >217°C 7LPH60 ~ 90s; Peak Temp.: 235 ~ 250°C (<245°C recommended) Time: 30 ~ 70s
Cooling zone — Peak Temp. ~ 180°C Ramp -down rate: -1 ~ -5°C/s
Solder — Sn&Ag&Cu Lead-free solder (SAC305)

Antenna Specifications

1 PCB Antenna

Model: ESP ANT B

PCB Antenna

Assembly: PTH

Gain:

Model

Test Item

Test
State

Frequency
(MHz)

Efficiency
(%)

Gain
(dB)

Note

ESP-ANT 8GainFree Space241273.792.39Vertical

30°

241777.042.97
242279.832.80
242781.192.89
243280.543.04
243776.862.86
244276.172.99
244773.992.96
245272.002.80
245770.712.72
246271.312.94
246771.323.12
247272.033.28
247772.713.24
248275.423.40

Dimensions:

Dimensions

Pattern Plots:

Pattern Plots
Pattern Plots

Revision History

be required as specified by 2.1093

DateVersionRelease notes
2020.02V0.1Preliminary release for certification CE& FCC.
OEM Guidance
  1.  Applicable FCC rules
    This module is granted by Single Modular Approval. It complies to the requirements of FCC part 15C, section 15.247 rules.
  2. The specific operational use conditions
    This module can be used in IoT devices. The input voltage to the module is nominally 3.3V-3.6 V DC. The operational ambient temperature of the module is -30 to 85 degree C. Only the embedded PCB antenna is allowed. Any other external antenna is prohibited.
  3. Limited module procedures
    N/A
  4. Trace antenna design
    N/A
  5. RF exposure considerations
    The equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20cm between the radiator and your body. If the equipment built into a host as a portable usage, the additional RF exposure evaluation may be required as specified by 2.1093.
  6. Antenna
    Antenna type: PCB antenna; Peak gain: 3.40dBi
  7. Label and compliance information
    An exterior label on OEM’s end product can use wording such as the following: “Contains Transmitter Module FCC ID: 2A9ZM-WROOM32E” or “Contains FCC ID: 2A9ZM-WROOM32E.”
  8. Information on test modes and additional testing requirements
    a)
    The modular transmitter has been fully tested by the module grantee on the required number of channels, modulation types, and modes, it should not be necessary for the host installer to re-test all the available transmitter modes or settings. It is recommended that the host product manufacturer, installing the modular transmitter, perform some investigative measurements to confirm that the resulting composite system does not exceed the spurious emissions limits or band edge limits (e.g., where a different antenna may be causing additional emissions).
    b)The testing should check for emissions that may occur due to the intermixing of emissions with the other transmitters, digital circuitry, or due to physical properties of the host product (enclosure). This investigation is especially important when integrating multiple modular transmitters where the certification is based on testing each of them in a stand-alone configuration. It is important to note that host product manufacturers should not assume that because the modular transmitter is certified that they do not have any responsibility for final product compliance.
    c)If the investigation indicates a compliance concern the host product manufacturer is obligated to mitigate the issue. Host products using a modular transmitter are subject to all the applicable individual technical rules as well as to the general conditions of operation in Sections 15.5, 15.15, and 15.29 to not cause interference. The operator of the host product will be obligated to stop operating the device until the interference have been corrected.
  9. Additional testing, Part 15 Sub part B disclaimer The final host / module combination need to be evaluated against the FCC Part 15B criteria for unintentional radiators in order to be properly authorized for operation as a Part 15 digital device

The host integrator installing this module into their product must ensure that the final composite product complies with the FCC requirements by a technical assessment or evaluation to the FCC rules, including the transmitter operation and should refer to guidance in KDB 996369. For host products with certified modular transmitter, the frequency range of investigation of the composite system is specified by rule in Sections 15.33(a)(1) through (a)(3), or the range applicable to the digital device, as shown in Section 15.33(b)(1), whichever is the higher frequency range of investigation When testing the host product, all the transmitters must be operating. The transmitters can be enabled by using publicly available drivers and turned on, so the transmitters are active. In certain conditions it might be appropriate to use a technology-specific call box (test set) where accessory 50 devices or drivers are not available. When testing for emissions from the unintentional radiator, the transmitter shall be placed in the receive mode or idle mode, if possible. If receive mode only is not possible then, the radio shall be passive (preferred) and/or active scanning. In these cases, this would need to enable activity on the communication BUS (i.e., PCIe, SDIO, USB) to ensure the unintentional radiator circuitry is enabled. Testing laboratories may need to add attenuation or filters depending on the signal strength of any active beacons (if applicable) from the enabled radio(s). See ANSI C63.4, ANSI C63.10 and ANSI C63.26 for further general testing details.
The product under test is set into a link/association with a partnering device, as per the normal intended use of the product. To ease testing, the product under test is set to transmit at a high duty cycle, such as by sending a file or streaming some media content.

FCC Warning:
Any Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment. This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) This device must accept any interference received, including interference that may cause undesired operation.

Version 0.1
Espressif Systems
Copyright © 2019

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ESPRESSIF ESP32-WROOM-32E 8M 64Mbit Flash WiFi Bluetooth Module [pdf] User Manual
WROOM32E, 2A9ZM-WROOM32E, 2A9ZMWROOM32E, ESP32-WROOM-32E 8M 64Mbit Flash WiFi Bluetooth Module, ESP32-WROOM-32E, 8M 64Mbit Flash WiFi Bluetooth Module, 64Mbit Flash WiFi Bluetooth Module, Flash WiFi Bluetooth Module, WiFi Bluetooth Module, Bluetooth Module, Module

References

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