Engineers say | Easily achieve HMI evolution using RX microcontroller and serial LCD!

In the past, when it comes to home appliances, their operation panels are usually composed of segmented LCD, LED and physical buttons. However, in recent years, more and more high-end models that focus on design have adopted TFT LCD and capacitive touch buttons.

In order to meet the demand for TFT LCD displays in home appliances and industrial equipment, Renesas has been developing the RX family of microcontrollers based on graphics LCD controllers and 2D graphics engines, and has been providing single-chip solutions that do not require peripheral LCD display ICs for many years. In order to make it easier to adopt TFT LCD modules in a wide range of applications, we have released an SPI-based GUI solution suitable for all RX family microcontrollers.

The advantages of SPI-based GUI solutions will be introduced below.

To achieve display control through SPI, only 4 terminals are used: clock output, data output/input and chip select. TFT LCD modules can also be controlled in packages with a small number of pins, so they can be successfully used in applications with limited component packaging area.

From development to mass production, all RX family microcontroller users can use Segger's GUI library "emWin for RX" for free. emWin has been optimized for embedded applications and can easily run even the RX100 series with less CPU and memory resources for LCD display.

The sample program we prepared uses the RX family microcontroller evaluation board (RX140, RX671) and a commercial QVGA LCD module. You can experience the microwave oven LCD display and application operations based on capacitive touch sensors at the same time.

In addition, we also provide a PoC so that you can experience the application of this solution in actual scenarios. Similar to the above sample program, the microwave oven operation interface can be displayed on the QVGA LCD module. Capacitive touch buttons and sliders are made of transparent electrodes that emerge white from the black shell when illuminated by LED backlight. In addition, because the front of the housing is completely flat, it gives a stylish HMI design feel. Combined with the circuit board schematics, transparent electrodes and housing design information published on the Web, customers can refer to it when developing products. If you plan to use this PoC, please contact your Renesas sales/agent.

PoC for SPI based GUI solution (not for sale)

Utilizing the RX family of SPI-based GUI solutions, you can achieve advanced HMI innovation with fewer hardware resources, so it is highly recommended for your next-generation product development.