Introduction: What Is the E291 Series?
In the Industrial Internet of Things (IIoT), an RF transceiver module is the core component that enables reliable, long-range, low-power wireless data exchange between devices. It modulates digital signals into RF carriers for transmission and demodulates received RF signals back into digital data — the "over-the-air bridge" connecting the physical and digital worlds.
The E291 series is a family of pure-RF transceiver modules designed by Chengdu EBYTE Electronic Technology Co., Ltd., based on the Panchip PAN3120 chip. The series supports up to 30dBm transmit power across the 410–510MHz band, and is characterized by small footprint, low power consumption and long-range communication. It includes several variants with different specifications, suited to smart home, industrial sensing, security and medical applications.
Because these are pure-RF transceiver modules, they must be driven by an MCU or controlled via a dedicated SPI debugging tool.
Who Needs It: Solving Real-World Pain Points
The E291 series serves four core user groups, addressing their pressing requirements:
| User Group | Typical Profile | Core Pain Point | E291 Solution |
|---|---|---|---|
| IIoT developers | Embedded engineers, system integrators | Need a long-range, low-power, high-reliability Sub-1G wireless module to connect sensors and actuators | 410–510MHz band, up to 30dBm TX power, ~8km measured range for industrial long-distance links |
| Smart-home product managers | Product managers, hardware engineers | Need to add wireless connectivity (smart curtains, lighting control) with small size, low power and easy integration | Multiple package sizes (as small as 10×10mm), low-power modes, easy MCU integration via SPI |
| Wireless meter-reading engineers | Power, water and gas utility engineers | Need long-range, anti-interference, low-power modules for remote automatic meter reading (AMI) | 30dBm high-power variant, ~8km range covers dispersed meters and reduces gateway deployment cost |
| Security system integrators | Security contractors, system integrators | Need reliable wireless links for alarm and access-control systems with stable signal delivery | Industrial wide-temperature design (-40℃~+85℃), multiple antenna options (IPEX/stamp hole) for harsh environments |
Product Overview
The E291 series comprises five products spanning two form factors — pure-RF modules and evaluation kits:
| Model | Form Factor | Core Positioning | Reference Range |
|---|---|---|---|
| E291-400M20S(3120) | RF module, 20dBm standard | Standard power, common size | 5000m |
| E291-400MM20S(3120) | RF module, 20dBm mini | Ultra-small, standard power | 5000m |
| E291-400M30S(3120) | RF module, 30dBm high-power | Ultra-long range, high power | 8000m |
| E291-400MBL-SC(3120) | Evaluation kit (low-power) | Works with E291-400M20S for quick evaluation | Depends on module |
| E291-400MBH-SC(3120) | Evaluation kit (high-power) | Works with E291-400M30S for quick evaluation | Depends on module |
Features & Model Comparison
4.1 Pure-RF Modules (E291-400M20S / MM20S / M30S)
E291-400M20S(3120) — Standard mid-power
Standard size 20.0×14.0mm, suitable for most generic designs.
Up to 20dBm TX power, ~5000m reference range.
Rich pinout: 22 pins including full SPI, GPIO, interrupt and reset.
E291-400MM20S(3120) — Mini mid-power
Ultra-compact 10.0×10.0mm, ~0.5g — ideal for space-constrained designs.
Same 20dBm TX power, ~5000m range.
20 pins in a tighter footprint.
E291-400M30S(3120) — High-power long-range
Up to 30dBm TX power, ~8000m reference range.
Larger 38.5×24.0mm to accommodate PA and heat dissipation.
Wide 2.1V~5.5V input, 5.0V recommended for full TX power.
~600mA instantaneous TX current — plan the power design accordingly.
Module Comparison Table
| Parameter | E291-400M20S(3120) | E291-400MM20S(3120) | E291-400M30S(3120) |
|---|---|---|---|
| Chip | PAN3120 | PAN3120 | PAN3120 |
| Carrier frequency | 410–510 MHz | 410–510 MHz | 410–510 MHz |
| TX power | 20 dBm | 20 dBm | 30 dBm |
| Reference range | 5000 m | 5000 m | 8000 m |
| Size | 20.0×14.0 mm | 10.0×10.0 mm | 38.5×24.0 mm |
| Weight | 1.5g ± 0.1g | 0.5g ± 0.1g | 4.9g ± 0.1g |
| Antenna | IPEX1 / stamp hole | Stamp hole | IPEX1 / stamp hole |
| Supply voltage | 1.8V~3.6V | 1.8V~3.6V | 2.1V~5.5V |
| TX current | ≈100 mA | ≈100 mA | ≈600 mA |
| RX current | ≈10 mA | ≈10 mA | ≈15 mA |
| Sleep current | ≈0.3 μA | ≈0.3 μA | ≈0.3 μA |
| RX sensitivity | -124 dBm (2.4kbps) | -124 dBm (2.4kbps) | -124 dBm (2.4kbps) |
| Pins | 22 | 20 | 22 |
| Operating temp | -40℃~+85℃ | -40℃~+85℃ | -40℃~+85℃ |
Evaluation Kits (E291-400MBL/MBH-SC)
E291-400MBL-SC(3120) — Low-power eval kit
Works with the E291-400M20S(3120) and other low-power SPI modules.
On-board STM32F103C8T6 MCU with preloaded test firmware — works out of the box.
Rich peripherals: 0.96" OLED display, Up/OK/Down keys, TXD/RXD/PWR LEDs, buzzer, test-resistor interface.
Type-C power input for easy hookup to a PC or power bank.
SMA antenna connector for external antennas.
Size: 30×74mm.
E291-400MBH-SC(3120) — High-power eval kit
Works with the E291-400M30S(3120) and other high-power SPI modules.
Same STM32F103C8T6 MCU.
Enhanced thermal and power design for high-power modules.
Size: 30×95.3mm — slightly longer to fit the larger high-power module.
Kit Function Details
| Feature | Description |
|---|---|
| Display | 0.96" OLED showing config, test parameters and version |
| UP key | Select/increment; long-press support in frequency & power setting |
| OK key | Confirm; move to next page or exit last page |
| DOWN key | Select/decrement; long-press support in frequency & power setting |
| TXD LED | Blinks on each transmission |
| RXD LED | Blinks on each reception |
| PWR LED | Solid when powered |
| Test resistor / TR | Remove to insert an ammeter in series and measure module current |
| Buzzer / BEEP | Beeps on key press |
Technical Parameters
General Parameters (Common)
| Parameter | Specification |
|---|---|
| Chip | PAN3120 |
| Crystal | 32MHz built-in passive crystal; no internal 32.768KHz low-frequency crystal |
| Interface | SPI, GPIO (user-developed) |
| Package | Stamp hole |
| Operating temp | -40℃~+85℃, industrial grade |
| Operating humidity | 10~95% RH, non-condensing |
| Storage temp | -40℃~+125℃ |
RF Parameters
| Parameter | Specification |
|---|---|
| Frequency band | 410~510 MHz |
| Modulation | 2(G)FSK, (G)MSK |
| Data rate | 0.2Kbps ~ 500Kbps |
Electrical Parameters
| Parameter | E291-400M20S(3120) | E291-400MM20S(3120) | E291-400M30S(3120) |
|---|---|---|---|
| Supply voltage | 1.8V~3.6V | 1.8V~3.6V | 2.1V~5.5V |
| Logic level | 3.3V | 3.3V | 3.3V |
| TX current | ≈100mA | ≈100mA | ≈600mA |
| RX current | ≈10mA | ≈10mA | ≈15mA |
| Sleep current | ≈0.3μA | ≈0.3μA | ≈0.3μA |
Application Scenarios
Industrial Sensor Data Collection
Recommended: E291-400M20S(3120) or E291-400M30S(3120) (long-range)
Deploy large numbers of sensors (temperature, humidity, pressure, vibration) in factories, warehouses and farms, streaming data wirelessly to a central gateway. Use the 20S for nearby nodes to balance power and cost; use the 30S for nodes crossing large plants or open areas, leveraging its 8km range to minimize relay nodes.
Smart-Home Central Control
Recommended: E291-400MM20S(3120) (mini, ideal for embedding)
Integrate the 10×10mm E291-400MM20S into smart-home devices (smart curtains, lighting panels, sensors). Its ultra-small footprint and low power make it ideal for embedded use. Communicate with the host MCU over SPI for device-to-device wireless linkage.
Wireless Meter Reading (AMI)
Recommended: E291-400M20S(3120) (low power, cost-effective)
Integrate the E291-400M20S into smart electricity, water and gas meters. Its low-power modes (≈0.3μA sleep) suit battery-powered meters, while 20dBm TX power with a good antenna covers all meters in a community for remote automatic reading — no manual visits required.
Rapid Prototyping & Evaluation
Recommended: E291-400MBL-SC(3120) or E291-400MBH-SC(3120)
The E291 evaluation kits provide an out-of-the-box platform. Developers can run range tests, parameter configuration and protocol validation directly — no need to design a baseboard or write drivers. The OLED display and keys offer an intuitive interface with real-time frequency and power adjustment, dramatically shortening the development cycle.
FAQ
Poor Transmission Range
Line-of-sight obstructions attenuate range accordingly.
Temperature, humidity and co-channel interference increase packet loss.
Ground absorption/reflection: testing near the ground degrades performance.
Seawater strongly absorbs RF; testing near the coast performs poorly.
Metal objects near the antenna or a metal enclosure heavily attenuate the signal.
Incorrect power-register settings or excessive over-the-air rate (higher rate = shorter range).
Supply below the recommended level at room temperature — lower voltage reduces TX power.
Poor antenna–module matching or low antenna quality.
Module Easily Damaged
Check the supply is within the recommended range; exceeding the maximum can permanently damage the module.
Ensure supply stability — avoid large, frequent voltage fluctuations.
Follow ESD precautions during installation; high-frequency components are ESD-sensitive.
Keep humidity in check during installation; some components are moisture-sensitive.
Unless necessary, avoid operation at extremes of temperature.
High Bit-Error Rate
Obstacles or co-channel interference between nodes — lower the over-the-air rate.
Unstable supply or interference — keep ripple low and add filtering.
Poor antenna/RF connector contact — check the antenna connection is secure.
About EBYTE
Founded in 2012, Chengdu EBYTE Electronic Technology Co., Ltd. is a national high-tech enterprise integrating R&D, production and sales. Headquartered in Chengdu with offices in Shenzhen, Guangzhou, Shanghai and Beijing, it serves customers in over 100 countries and regions worldwide. EBYTE focuses on industrial IoT wireless communication, with a portfolio spanning wireless modules, radio modems, industrial gateways, network I/O, industrial PCs, antennas and accessories.
Technology philosophy: EBYTE is committed to the mission of "making wireless communication simpler and the IoT world smarter," delivering stable, high-performance, cost-effective RF modules and solutions that drive industrial automation and intelligence.
Choosing the EBYTE E291 series means choosing a professional, reliable, high-efficiency Sub-1G wireless communication core platform.
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