WiFi LoRa 32 V4 Wi-Fi/Bluetooth/LoRa Battery Management 0.96inch OLED Documents Rev 1.4 P 1/15 August, 2025 Heltec Automation Limited standard files Document Version Version Time Description V4.1.0 2025-08-11 Internal beta version V4.2.0 2025-09-11 First Official Release Version V4.3.1 2025-12-11 Change PA Remark Richard Richard Richard Documents Rev 1.1.0 P 2/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org Copyright Notice Disclaimer All contents in the files are protected by Chengdu Heltec Automation Technology Co., copyright law, and all copyrights are reserved Ltd. reserves the right to change, modify or by Chengdu Heltec Automation Technology Co., improve the document and product described Ltd. (hereinafter referred to as Heltec). Without herein. Its contents are subject to change written permission, all commercial use of the without notice. These instructions are intended files from Heltec are forbidden, such as copy, for you use. distribute, reproduce the files, etc., but non-commercial purpose, downloaded or printed by individual are welcome. Documents Rev 1.4 P 3/15 August, 2025 Heltec Automation Limited standard files Content 1. Introduction .............................................................................................................................................................. 5 1.1 Overview ............................................................................................................................................................. 5 1.2 Features ...............................................................................................................................................................5 1.3 Application Scenarios ..................................................................................................................................... 5 1.4 Components .......................................................................................................................................................6 2. Pin Definition ........................................................................................................................................................... 7 2.1 Pin Layout ...........................................................................................................................................................7 2.2 Pin Description ................................................................................................................................................. 8 2.2.1 Header J2 ........................................................................................................................................................ 8 2.2.2 Header J3 ........................................................................................................................................................ 9 2.2.3 Additional Pins .............................................................................................................................................. 10 2.2.4 Peripherals (I2C/SPI/UART/I2S/PWM/etc.) ...................................................................................................10 3. Specifications ......................................................................................................................................................... 11 3.1 General specifications .................................................................................................................................. 11 3.2 Power Supply .................................................................................................................................................. 11 3.3 Power Output ................................................................................................................................................. 12 3.4 Power Consumption(25 .......................................................................................................................13 3.5 LoRa RF Characteristics ............................................................................................................................... 13 3.5.1Receiving Sensitivity ....................................................................................................................................13 4. Dimensions ..............................................................................................................................................................13 5. FCC Statement ........................................................................................................................................................14 6. Resource ...................................................................................................................................................................15 6.1 Relevant Resource ......................................................................................................................................... 15 6.2 Contact Information ..................................................................................................................................... 15 Documents Rev 1.1.0 P 4/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 1. Introduction 1.1 Overview Heltec WiFi LoRa 32 V4 is a fully upgraded version of the classic LoRa development board. Since its initial launch in 2017, this product series has been highly favored by developers and makers. Building upon the powerful features of its predecessors, the V4 version introduces comprehensive optimizations in Transmit Power, power management, expandability and other hardware design. It is suitable for various IoT applications such as smart cities, agricultural monitoring, smart homes, industrial control, security systems, and wireless meter reading, providing developers with a more efficient and flexible development experience. 1.2 Features Base on ESP32-S3R2 & SX-1262, supports Wi-Fi b/g/n, BLE, and LoRa communication. 2MB PSRAM and 16MB external Flash, more suitable for UI and complex system . Form factor and pin compatibility with WiFi LoRa 32 V3. PC casing protects the screen and integrates FPC 2.4G antenna. Added SH1.25-2P solar panel interface. Optimized lithium battery management. Added SH1.25-8Pin GNSS interface. USB Type-C interface with integrated voltage regulation, ESD protection, short-circuit protection, and RF isolation design;
Low power consumption is less than 20A. 1.3 Application Scenarios Environmental Sensor Industrial Internet of Things Asset Tracking Remote Meter Reading Smart Agriculture Wireless Alarm Innovative Projects and Geek Application Documents Rev 1.1.0 P 5/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 1.4 Components Documents Rev 1.1.0 P 6/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 2.Pin Definition 2.1 Pin Layout The following figure shows some common information and descriptions of the WiFi LoRa 32 pins. For more detailed functional information about each pin, please refer to the ESP32 chip manual. ESP32-S3 MCU Datasheet. Documents Rev 1.1.0 P 7/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 2.2 Pin Description 2.2.1 Header J2 No. Name Type GND 5V Ve Ve RX TX G P P P I/O I/O Table 2.2.1: Pin description Function Ground 5V Power Supply Output 3.3V Output 3.3V IO MUX GPIO44, U0RXD IO MUX GPIO43, U0TXD RST I CHIP_PU, Reset Button 0 36 35 34 33 47 48 26 21 20 19 I/O I/O I/O I/O I/O I/O I/O I/O I/O IO MUX GPIO0, PRG Button IO MUX GPIO36,SPIIO7,FSPICLK,SUBSPICLK,Vext_Ctrl IO MUX GPIO35, SPIIO6,FSPID, SUBSPID, LED IO MUX GPIO34, SPIIO5,FSPICS0, SUBSPICS0 IO MUX GPIO33, SPIIO4,FSPIHD, SUBSPIHD IO MUX GPIO47, SPICLK_P_DIFF,SUBSPICLK_P_DIFF IO MUX GPIO48,SPICLK_N_DIFF,SUBSPICLK_N_DIFF IO MUX GPIO26, SPICS1 RTC IO MUX GPIO21, OLED RST I/O Analog RTC IO MUX GPIO20,U1CTS,ADC2_CH9, USB_D+
I/O Analog RTC IO MUX GPIO19,U1RTS,ADC2_CH8, USB_D-
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Documents Rev 1.1.0 P 8/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 2.2.2 Header J3 No. Name Type P P P I/O I/O I/O I/O I/O I/O I/O I/O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 GND 3V3 3V3 37 46 45 42 41 40 39 38 1 2 3 4 5 6 7 Table 2.2.2: Pin description Function Ground. 3.3V Power Supply 3.3V Power Supply IO MUX GPIO37, SPIDQS, FSPIQ, SUBSPIQ, ADC Ctrl IO MUX GPIO46 IO MUX GPIO45 IO MUX GPIO42, MTMS, GNSS_RST IO MUX GPIO41, MTDI, GNSS_PPS IO MUX GPIO40, MTDO, GNSS_Wakeup IO MUX GPIO39, MTCK, GNSS_TX IO MUX GPIO38, FSPIWP, SUBSPIWP, GNSS_RX I/O Analog RTC IO MUX GPIO1, ADC1_CH0, TOUCH1, VBAT_Read1 I/O Analog RTC IO MUX GPIO2, ADC1_CH1, TOUCH2 I/O Analog RTC IO MUX GPIO3, ADC1_CH2, TOUCH3 I/O Analog RTC IO MUX GPIO4, ADC1_CH3, TOUCH4 I/O Analog RTC IO MUX GPIO5, ADC1_CH4, TOUCH5 I/O Analog RTC IO MUX GPIO6, ADC1_CH5, TOUCH6 I/O Analog RTC IO MUX GPIO7, ADC1_CH6, TOUCH7, VFEM_Control 1 ADC1_CH0 is used to read the lithium battery voltage, the ADC_CTRL(37) pin needs to be pulled high. the voltage of the lithium battery is:
VBAT = 100 / (100+390) * VADC_IN1 Documents Rev 1.1.0 P 9/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 2.2.3 Additional Pins Table 2.2.3: Additional Pin No. Name Type Function 1 2 3 4 18 17 16 15 I/O Analog RTC IO MUX GPIO18, OLED_SCL I/O Analog RTC IO MUX GPIO17, OLED_SDA I/O Analog RTC IO MUX GPIO16, XTAL_32K_N I/O Analog RTC IO MUX GPIO15, XTAL_32K_P 2.2.4 Peripherals (I2C/SPI/UART/I2S/PWM/etc.) ESP32-S3 can integrates a rich set of peripherals. To learn more about on-chip components, please refer to ESP32-S3 MCU Datasheet. Owing to the GPIO Matrix and IOMUX capabilities, the vast majority of GPIO pins can be configured for functions such as I2C, SPI, I2S, PWM or UART. For specific pin assignments and IOMUX correspondences, please refer to the list of pins marked with IOMUX functionality in Appendix Tables 2.2.1 and 2.2.2. Note: The original functionality of the reconfigured pins will be affected. Please select appropriate pins for your application. Such as OLED has occupied one I2C interface, while LoRa and Flash have each utilized a separate SPI interface. Documents Rev 1.1.0 P 10/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 3.Specifications 3.1 General specifications Parameters Description Master Chip ESP32-S3R2 LoRa Chip Frequency SX-1262 902~928 MHz Max. Receiving Sensitivity
-137 dBm Table 3.1: General specifications Wi-Fi Bluetooth OLED 802.11 b/g/n, up to 150Mbps Bluetooth LE, Bluetooth 5, Bluetooth mesh SSD1315(0.96Inch, 128*64 resolution) Power Supply 5V@USB/Solar, 3.3-4.2V@Battery Hardware Resource 7*ADC1 + 2*ADC2, 7*Touch, 3*UART, 2*I2C, 2*I2S, 4*SPI, etc. Memory 384KB ROM; 512KB SRAM; 16KB RTC SRAM; 16MB Flash; 2MB PSRAM Interface solar panel interface; 2*IPEX1.0 ANT(LoRa&2.4G); 2*18*2.54 USB Type-C; SH1.25-2P lithium battery interface; SH1.25-2P Operating Temperature
-40~85(OLED operating temperature: -40~ 70C) Header Pins, 2*2*2.54 Header Pins Dimensions 51.7 * 25.4* 10.7mm 3.2 Power Supply USB or 5V can only be connected to one of them. When either USB or 5V input is connected, the solar panel and lithium battery can be connected simultaneously. Documents Rev 1.1.0 P 11/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org Table 3.2: Power supply Power Supply Mode Minimum Typical Maximum Company Type-C USB(500mA) Lithium battery(250mA) 5V pin(500mA) 3V3 pin(150mA) Solar Panel 4.7 3.3 4.7 2.7 4.7 5 3.7 5 3.3 5 6 4.2 6 3.5 6 V V V V V 3.3 Power Output When using VE for external power supply, the VextCtrl(GPIO36) pin needs to be pulled high. Pin 3.3V 5V@USB Ve Minimum Typical Maximum Company Table 3.3: Power output 500 500 500 mA mA mA Documents Rev 1.1.0 P 12/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 3.4 Power Consumption(25 Mode Condition Min. Typical Max. Unit Table 3.4: Power consumption WiFi Scan USB powered WiFi AP USB powered BT TX RX USB powered USB powered TX disabled; RX enabled USB powered Sleep Battery powered 3.3V header powered Charging USB@5V 119 170 115 750 75 2 20 20 500 mA mA mA mA mA mA A A mA 3.5 LoRa RF Characteristics 3.5.1Receiving Sensitivity The following table gives typically sensitivity level. Signal Bandwidth/[KHz]
Spreading Factor Sensitivity/[dBm]
Table3.5.2: Receiving sensitivity 125 125 125 SF12 SF10 SF7
-137
-131
-122 4.Dimensions Documents Rev 1.1.0 P 13/15 Sep. 2025 HelTec Automation Limited standard fileshttps://heltec.org 5.FCC Statement This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to 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 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 or more 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. To assure continued compliance, any changes or modifications not expressly approved by the party. Responsible for compliance could void the users authority to operate this equipment. (Example- use only shielded interface cables when connecting to computer or peripheral devices). This equipment complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
Documents Rev 4.2.0 P 14/15 Sep. 2025 HelTec Automation Limited standard files https://heltec.org
(1) This device may not cause harmful interference, and
(2) This device must accept any interference received, including interference that may cause undesired operation. FCC Radiation Exposure Statement:
The equipment complies with FCC Radiation exposure limits set forth for uncontrolled enviroment. This equipment should be installed and operated with minimum distance 20cm between the radiator and your body. 6.Resource 6.1 Relevant Resource User Guide SDK Heltec ESP (ESP32 & ESP8266) framework Heltec ESP32 library Schematic diagram Downloadable resource 6.2 Contact Information Heltec Automation Technology Co., Ltd Chengdu, Sichuan, China Email: [email protected] Phone: +86-028-62374838 https://heltec.org Documents Rev 4.2.0 P 15/15 Sep. 2025 HelTec Automation Limited standard files https://heltec.org
