SmartRC CC1101 Driver Library (V3.0.1)

This is the official evolution of the SmartRC CC1101 library. After years of community use (Versions up to 2.5.7), the entire driver core has been completely re-engineered for 2026 to ensure maximum precision, stability, and minimal resource footprint.

💎 The Evolution: Legacy vs. V3.0.0

While the original versions relied on experimental values and global variables, V3.0.0 strictly follows the physical formulas provided in the Texas Instruments CC1101 datasheet and features a modern, object-oriented design.

Key Technical Improvements:

• Read-Modify-Write (RMW) Logic: Instead of mirroring chip states in the microcontroller's RAM, the driver now operates bit-precisely directly on the hardware registers. This saves significant RAM on systems like the Arduino Nano/Uno.

• Mathematical Precision: Frequencies, data rates, and bandwidths are now calculated using exact logarithmic formulas, drastically increasing link stability.

• Object-Oriented Architecture: Full support for multi-module setups (e.g., Dual-Band Gateways 433/868 MHz) via class instantiation. Old sketches remain 100% compatible via the provided wrapper!

• Hardware Feedback: New "Plain-Text" Getters (getMHZ(), getDRate(), etc.) allow you to verify the actual internal settings of the chip for the first time.

⚠️ Backwards Compatibility & Removed Functions

We kept the transition as smooth as possible. Most legacy sketches using ELECHOUSE_CC1101 will compile and run out-of-the-box thanks to a built-in wrapper!

However, to keep the library clean and professional, we removed the outdated multi-module workaround functions:

• ❌ setModul(), addSpiPin(), addGDO(), addGDO0() have been removed.
• ✅ New Approach: If you want to use multiple CC1101 modules, simply instantiate multiple objects (e.g., SmartRC_CC1101 radio1; and SmartRC_CC1101 radio2;).

🛠 Issue Policy & 2026 Reboot

With the release of Version 3.0.0 in April 2026, the library architecture has been fundamentally changed.

What does this mean for open issues?

• Legacy Issues: All issues reported before April 2026 refer to the outdated V2.x architecture. As these versions are no longer actively maintained, these issues have been closed and moved to the "Legacy V1.x/V2.x" milestone.

• A Fresh Start: If you encounter a bug with the new version, please open a new issue.

• Prerequisite: Ensure you are using the new object-oriented structure and that your problem is reproducible with the current V3.0.0 release.

🔌 Hardware Wiring

CC1101 Pin	Arduino Uno/Nano	ESP32 (Default)	Description
VCC	3.3V	3.3V	Power Supply (3.3V ONLY!)
GND	GND	GND	Ground
SCK	Pin 13	GPIO 18	SPI Clock
MISO	Pin 12	GPIO 19	SPI Data Out
MOSI	Pin 11	GPIO 23	SPI Data In
CSN / SS	Pin 10	GPIO 5	Chip Select
GDO0	Pin 2	GPIO 2	Interrupt/Data Out

🚀 Quick Start

#include <SPI.h>
#include "SmartRC_CC1101.h"

// Create an instance
SmartRC_CC1101 radio;

void setup() {
    Serial.begin(115200);
    radio.Init();
    radio.setMHZ(433.92);
    radio.SetRx();
    
    if(radio.getCC1101()) {
        Serial.println("Hardware found and ready!");
    }
}

void loop() {
    if (radio.CheckReceiveFlag()) {
        byte buffer[64];
        byte len = radio.ReceiveData(buffer);
        // Process data...
    }
}

🔬 Hardware Calibration (New in V3.0.0)

A common issue with inexpensive CC1101 modules is a severe deviation of the integrated 26 MHz crystal oscillator (often ±20 ppm to ±30 ppm). This causes the module to transmit slightly off-center (e.g., at 433.911 MHz instead of 433.920 MHz), leading to massive range loss with narrow-band receivers.

Check the examples/ folder for our new Calibration Tool. With the help of an SDR (Software Defined Radio) and the Serial Monitor, you can completely eliminate this hardware flaw:

• Band Calibration Tool: A guided script to measure the upper and lower limits of an entire frequency band (e.g., the 433 MHz band). It calculates the perfect FSCTRL0 register offsets and outputs ready-to-use C++ code (myRadio.setClb(...)) to permanently tune your specific hardware module!

🙏 Acknowledgments & History

This library was originally based on the Elechouse CC1101 Library by Wilson Shen. A sincere thank you goes to Wilson and the Elechouse team for their kind permission to modify and evolve this code. Their original work made this community-standard driver possible.

Visit the original source at: www.elechouse.com

📜 License

Released under the MIT License. Author: Little Satan (SmartRC) Revision: April 2026