Is RLCD the Display Technology You’ve Been Waiting For?

If you want a digital display for your project, you’ll probably turn to some form of LCD or OLED. They’re affordable, are available in many formats and resolutions, and have fast refresh rates. But if you want to reduce power consumption and read in sunlight, you might grab an E Ink screen. The only problem is that E Ink refresh rates are horrible. That’s why this RLCD screen, demonstrated by Volos Projects, might be the best of both worlds.

An RLCD (reflective liquid crystal display) is similar to the old school monochrome LCDs that lacked backlights, except it has reflective particles that create very good visual contrast in direct light (including sunlight). RLCD panels consume minimal power, but also have high resolutions and fast refresh rates.

The unit Volos tests in the video is from Waveshare and is built into an all-in-one unit with an ESP32-S3 development board, with a holder for an 18650 lithium battery, a microSD card slot, several additional sensors and buttons, and even a dedicated audio codec chip. The RLCD itself is 4.2” with a resolution of 300×400. Depending on what you’re doing, this product may already have all of the hardware you need.

The video focuses on evaluating that product, with particular emphasis on the performance of the RLCD in sunlight. And in that setting, it seems to do extremely well. Even with the sun bouncing directly off the screen, the display content is still very visible. On top of that, Volos was able to get more than 80fps from the display.

The big disadvantage, of course, is the lack of backlight. That means the display will be unusable in the dark, which may be a dealbreaker in many situations. But the same is true of many E Ink screens. The value here, compared to E Ink, is in the much faster refresh rate, at the expense of battery life.