【Training Camp】Light Strip Controller

# Introduction A light bar touch panel controller based on the Renesas R7FA2E1A72DFL#AA32-bit series microcontroller. ### Chip Features R7FA2E1A72DFL#AA is an entry-level single-chip microcontroller of the RA series, based on the 48 MHz Arm® Cortex®-M23 core, with up to 128 kB of code flash memory and 16 kB of SRAM. This product uses an optimized process and Renesas Electronics' low-power process technology. The product supports a wide operating voltage range of 1.6V to 5.5V and a variety of packages, such as LQFP, QFN, LGA, BGA and WLCSP. The RA2E1 is pin- and peripheral-compatible with the RA2L1 product group, making it ideal for battery-powered and space-constrained applications, as well as other systems requiring high performance and low power consumption. * 48MHz Arm® Cortex®-M23; * Wide operating voltage range of 1.6V - 5.5V; * Enhanced capacitive touch sensing unit (CTSU); * Independent SPI interface/I2C multi-master interface; * 12-bit ADC, LPACMP , temperature sensor; * 32-bit universal PWM timer, 16-bit universal PWM timer, low-power asynchronous universal timer; # Function introduction of the work * Two voltage inputs * Input voltage: 1.6V - 5.5V * Two PWM outputs * Potentiometer dimming * Three-way capacitive touch button ** This work is a case project of Lichuang EDA training camp, which is used to understand the learning and use of chips. The content and functions are simple and suitable for entry-level learning** # Control description * T0 switch ( Default output cold and warm 1:1) * T1 cold light 3-level adjustment (output out1: out2 1:0.8 1:0.6 1:0.4) * T2 warm light 3-level adjustment (output out1: out2 0.8:1 0.6:1 0.4:1) *Potentiometer adjusts brightness (5 levels) #Hardware description### Power input Since this case does not need to use a USB data cable for direct programming, and the microcontroller supports a wide voltage input of 3-5V, the light bar is also controlled by 5V, so There is no need to convert other voltage inputs, so only the 6-pin USB Type-C is used as the voltage input, and a CONN 2P 5mm pitch connector power input is also expanded for easy use. ![image.png] ### The MUC minimum system R7FA2E1A72DFL#AA chip can be used with only simple peripheral circuits and does not require too many circuits. **Power supply** What the R7FA2E1A72DFL microcontroller needs to ensure is that all power input pins must be connected before it can be used. Each power input pin needs to add a 100nF filter capacitor. The P112 pin is the reference capacitance pin of the touch button. , if you want to use the touch button function, then this reference capacitor must be connected before it can be used. ![image.png] **Reset circuit** The reset pin of R7FA2E1A72DFL is above the bottom 19 pin (RST). In order to reduce the size of the board, the reset circuit uses a side-press touch button to reduce the size. ![image.png] **Programming circuit** The R7FA2E1A72DFL microcontroller programming circuit only supports serial port programming and Jlnk V7 version or above, and ST-lnk cannot be used. When using the serial port programming pins, you need to pay attention to the 20th pin (MD) of the MCU. It is the BOOT selection of the serial port. The system defaults to pull-up. When programming, you need to pull down the chip to enable serial port programming. You can use the pin header or buttons to do this. BOOT selection. ![image.png] ### Touch capacitive button Three-way touch capacitive button. The hardware design of the touch button needs to refer to the official standard case document for design. The touch button needs to be grounded at a single point. If not grounded at a single point, it may affect The sensitivity of the touch keys decreases. Please download and view the official design manual in the attachment. ![image.png] ### The potentiometer dimming input dimming part uses a vertical in-line potentiometer. The microcontroller detects the ADC value and outputs PWM to change the brightness of the light bar. ![image.png] ### Since the two outputs need to control the light bar, the current of the microcontroller io may not be able to drive, so we need a drive circuit. Here we use a PWM composed of the very common AO3400AN channel 30V 5.8AMOS tube. Drive circuit. ![image.png] The above is an overall circuit introduction for this training camp. I won’t explain too much about the PCB design part. You can watch the video tutorial for details. Final note: This project is just a reference case. The works produced by the training camp need to be produced by everyone on their own. Don't think about Ctrl C+V and it's done.