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+