What is The Best IC Pixel Type for My LED Display?
When it comes to LED lighting, the sheer volume in the variety can be more confusing than helpful. Not all LED strips or strings are created equal, so your best option towards finding the perfect solution for your lighting needs will be dependent on your particular use case.
While a wide variety of pixel types exist, Advatek support 50+ IC chips with the pixel protocol list, and we are continually adding protocols all the time. For this article we’ll be focusing particularly on three very distinct protocols, which are listed below:
Sometimes referred to as neopixels, this integrated light source usually comes in a variety of colours alongside a driver that is concealed inside a 5050 sized (5mm x 5mm) RGB LED package. This pixel type is data only and is popular for its simple design. It doesn’t need a clock line and boasts an impressive small form-factor and so is easily mountable on a flexible PCB strip, like Advatek’s DCDC LED Strip range.
The WS2812B operates on a 400Hz Pulse Width Modulated (PWM) frequency rate. Although this rate provides persistence of vision for the human eye, it will not translate well to cameras. When shooting with a 24fps camera, the minimum PWM rate of the pixels you’re filming should be about 720Hz, so this pixel type will not be adequate for cameras.
WS2812B Refresh Rates
Refresh rates depend on several factors in your pixel control system. One of these factors is whether the pixels are data-only or clocked. Clocked pixel types can allow for higher and adjustable data speeds, which may affect your overall refresh rate. As the WS2812B pixel type is data-only, its data speeds and the overall refresh rate will not benefit from a clocked data transmission. Whether or not this is a concern for you depends on your specific use case. If you’re creating a lighting display of fast and dynamic lights, and you need a large number of pixels connected in series, then this pixel type may result in a low overall refresh rate. See Refresh Rates for more detail.
Despite this, the WS2812B is the most popular LED driver, particularly for systems with a low pixel count, due to its simplicity and multitude of applications. It is widely manufactured and readily available. If you’re after a simple solution on a budget, this is the system for you.
This later version in the WS28xx line offers more features and a higher quality pixel than the previous WS2812B. The form factor is an identical size, making it a good pixel type for PCB strip, however it uses six pins per chip, rather than four. One pin is to allow for redundancy in the data line, and another is to allow for a higher voltage to drive the LEDs.
The first main feature of this pixel type is the backup data line. Although only one data line is used to connect the LED strip to the PixLite controller, the first pixel creates an identical second data line as a backup. The benefit of this is that if a pixel fails, or there is a break in the data line at any point beyond pixel 1, the backup data line can be used by the pixels to receive the same data. If another pixel fails, the backup data line still provides that redundancy. In fact, the entire strip should never fail from a break in the data unless 2 adjacent pixels fail.
WS2815 Up Close
Secondly, WS2815 runs off 12V instead of 5V, regulating the voltage down internally. While this does mean that each LED runs at a slightly more elevated temperature than if it were receiving a 5V input directly, the benefit of this in terms of overhead is obvious when wanting to power longer chains of pixels. See 12V vs. 5V for more detail.
Lastly, WS2815 offers a higher PWM rate than WS2812B, increasing it from 400Hz to 2kHz. This makes it suitable for filming with a 66fps or lower camera. The refresh rate of this pixel is still quite low compared to clocked pixel chips so it’s not suitable for all applications.
If data redundancy and standard film quality is a need in your lighting system, then WS2815 is for you.
This high-end pixel type boasts an impressive 16-bit colour resolution at a fast PWM rate. This chip type is clocked, and so requires an extra line to be connected to your PixLite controller. It also is a larger physical chip, and so is usually installed within moulded casings along a string of LEDs.
MY9231 Up Close
The addition of a clock line can improve data speeds from the pixel controller to the LEDs. If your pixel system is not limited by other factors, the addition of a clock can improve your overall refresh rate. In addition, the clock frequency can be modified within the Advatek Assistant, allowing for more flexibility. As a general rule, increasing the clock speed will give you a higher refresh rate (ideal for faster and more dynamic lighting systems), and decreasing the clock speed will allow for a slightly longer distance of cable between the controller and the first pixel. See Adjustable Clock Rates for more detail.
This chip drives the brightness of its LEDs with 16-bit data, allowing for more precise colour mixing and accurate brightness levels when a gamma correction curve is employed. PixLite controllers operate MY9231 chips in 16-bit mode to achieve this feature, and an adjustable gamma value slider is provided in the Advatek Assistant to achieve optimal results. At 16-bit resolution, MY9231’s PWM rate is 2kHz, ideal for cameras operating below 66fps. This makes this pixel type perfect for capturing events with high quality cameras.
MY9231 is the pixel of choice if you’re in need of high colour resolutions and high refresh rates.
Get in touch with the team at Advatek Lighting
If you’re still unsure about the best addressable LED lighting solution for your next project, get in touch with the team at Advatek Lighting. Not only are we keen to find out more about your lighting needs, but we’ll help you select the right rgb led pixel controller for your ambitions and light up your designs.