Renard
Renard
Renard is a serial communication protocol and family of DIY Christmas lighting controllers developed specifically for animated holiday displays. Introduced in the mid-2000s, the Renard system became one of the first affordable controller platforms available to hobbyists and helped establish the modern DIY Christmas lighting community.
Although many new displays now use smart pixels, Renard controllers remain reliable, inexpensive, and well suited for controlling conventional AC lighting, DC lighting, and relay outputs.
Overview
The Renard system consists of:
- Sequencing software or show player
- Renard controller
- RS-485 or serial communications
- Solid State Relays (SSR) or onboard outputs
- Conventional lighting loads
Renard controllers are designed primarily for dimming traditional Christmas lights rather than individually addressable pixels.
History
The Renard project was developed by members of the DIY Christmas lighting community as an inexpensive, open-source alternative to commercial lighting controllers.
Its introduction significantly lowered the cost of animated Christmas displays and encouraged widespread experimentation and innovation within the hobby.
Over time, numerous Renard-compatible controller designs were created by community members.
How Renard Works
Lighting data is transmitted from the sequencing software to one or more Renard controllers.
The controller converts the received serial data into dimming or switching outputs.
A typical signal path is:
xLights or FPP
↓
Renard Data
↓
RS-485 Network
↓
Renard Controller
↓
SSR or Onboard Outputs
↓
Christmas Lights
Multiple Renard controllers may be daisy-chained together.
Communication
Renard commonly communicates using:
- RS-232
- RS-485
Many modern systems use RS-485 because it provides:
- Long cable lengths
- Good noise immunity
- Reliable multi-controller operation
Renard Controllers
Several Renard controller families have been produced, including:
- Renard 8
- Renard 16
- Renard 24
- Renard 64
- Ren-W
- Numerous custom community designs
Many boards remain in service today.
Solid State Relays
Many Renard systems use external SSR modules.
Advantages include:
- Isolation from line voltage
- Flexible installation
- Easy expansion
- Simple replacement
Some controllers include onboard dimming circuitry instead.
Renard and Pixels
Renard was designed before smart pixels became common.
As a result:
- Renard controls channels.
- Pixel controllers control individual RGB pixels.
Many displays successfully combine both technologies.
For example:
- Renard controls house lights.
- Pixel controllers control animated props.
Renard and ESP Controllers
Modern firmware such as ESPixelStick allows ESP8266 and ESP32 controllers to emulate Renard outputs.
This makes it possible to continue using existing Renard controllers while replacing long serial cables with Wi-Fi or Ethernet connections.
Many hobbyists have modernized older displays using this approach.
Advantages
- Proven reliability
- Low cost
- Excellent dimming
- Large installed base
- Open hardware
- Simple architecture
- Ideal for conventional lighting
Limitations
- Not intended for smart pixels
- Lower channel density than modern pixel controllers
- Serial communication
- Requires separate pixel controllers for RGB pixels
Christmas Lighting Recommendations
Renard remains an excellent choice for:
- AC mini lights
- Incandescent displays
- LED string lights
- Relay outputs
- Existing Renard installations
For new smart-pixel displays, protocols such as DDP and E1.31 used with modern pixel controllers are generally recommended.
Many hobbyists successfully operate both Renard and pixel controllers in the same display.