PIC18, MPLAB X IDE, XC8, SPI, at45dbxx data flash 4MHz frequency 에서 spi clock으로 1MHz를 사용합니다. - RC3 : CLK - RC4 : SDI - RC5 : SDO - RA5 : CS 0. 참고 사항https://openlabpro.com/guide/spi-module-in-pic18f4550/https://www.waveshare.com/wiki/Open18F4520 [ ] https://www.microchip.com/wwwproducts/en/PIC18F4520[ datasheet ] http://ww1.microchip.com/downloads/en/devicedoc/39631a.pdf 1. HW 연결 2. 소스 설명full 소스는..