**Breadboard friendly dev board for ATmega328P-PU (DIL-28) with NRF24L01+ (optional)** Version 1.1: rotated NRF24L01+ 90° to prevent EMI packet loss - Designed to run at 8MHz (with ATmega328 internal oscillator, no external crystal) - MCP1700T-3302E/TT (250mA) voltage regulator with low quiescent current for battery operation - With header for FTDI programmer (e.g. "FTDI Basic Breakout 3.3V") - Seperate AGND and GND copper area to reduce analog noise (note that I'm a PCB design beginner, so it may not be the best design with seperate GND areas) - optional inductor to reduce analog noise - optional 10uF tantal and 100nF ceramic capacitors to improve NRF24L01+ transmission - optional I2C pullups - optionally connect NRF24L01+ IRQ pin to D8 via solder pad SB1 - mostly 0805 footprints (tantal capacitor: CASE-B_3528) See "23.6.2 Analog Noise Canceling Techniques" in the ATmega328 datasheet why there is an analog GND copper area and an inductor. http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdf **BEFORE USAGE** - Decide if you want to use an inductor (L1) to reduce analog noise, or if it's unnecessary for your project. If you don't use an inductor you **MUST** solder a bridge over SB2 ("NO INDUCTOR") - You **MUST** solder the zero Ohm resistor to connect GND and AGND (I didn't find a better solution in EasyEDA) You can basically leave out all the capacitors, but if you want to use a FTDI programmer, you must solder the capacitor named C-RST Also, leaving out the capacitors C-VIN and C-VOUT may break your voltage regulator. But I found the MCP1700 can run without them for hours without damage. Use this board in Arduino IDE: https://raw.githubusercontent.com/oshlab/Breadboard-Arduino/master/avr/boardsmanager/package_oshlab_breadboard_index.json **WARNING** Only use FTDI programmer with 3.3V when NRF24L01+ is connected. Using 5V may destroy your NRF24L01+