86 Color Temperature Control Box

Traditional thermostats use monochrome LED or LCD solutions. In the past, the price of color LCD was out of reach. However, as demand increases and production expands, the price gradually becomes more affordable, which in turn makes the display screens of household appliances gradually move towards color LCD. Through the color LCD, the status display of temperature, weather and humidity can be made more humane, and more interactive effects can be made, including time switches, settings, etc., which can have more amazing performances.

Specification requirements for color thermostats:

• The chroma needs to be true color 18-bit or 24-bit: the display fineness of the chroma will affect the performance of graphic colors, thereby affecting the user's perception.
• It is necessary to use the proprietary protocol MODBUS RTU through the RS485 interface to control peripherals, such as temperature switches and temperature sensors.
• The touch panel screen is smooth: control smoothness will affect user satisfaction
• Graphical control interface process: Provides a user interface that is convenient for design, which can speed up the process of products entering mass production.

Nuvoton Technology's newly launched color thermostat box reference design provides a complete solution, starting from the hardware design. It uses the graphics control series product N9H20 microprocessor and built-in 32 MB SDRAM memory, which reduces the hardware design effort. Difficulty, built-in large-capacity memory brings three major benefits:

First, the circuit design is simple, the PCB design is simple, and the PCB area is reduced.

Second, it reduces external high-speed signals, greatly reduces electromagnetic interference, and easily passes safety regulations (FCC/CE/BSMI/CCC) tests.

Third, using LQFP packaging, it is easy to debug and maintain.

This solution provides a complete hardware design including circuit design, RS485 circuit, and PCB layout. In terms of software design, a complete graphic of the thermostat is provided, including the startup screen, three-page sliding mode switching, temperature display, temperature control, perpetual calendar, backlight control, and RS485 control. The entire software uses open software, allowing users to change processes and pictures according to their own plans, and users can directly download and use related pictures.

Complete set of reference design specifications

related resources

• Thermostat Reference Design User Manual
• Thermostat HMI Gerber & Schematic PCB File
• Thermostat HMI example code
• Thermostat HMI Gitee