Raspberry Pi – Revision 2 DIY Add-On Board

On the Raspberry Pi, there are several connections which can be used for expansion:
1,  The Rpi GPIO (General Purpose Input/Output) pins are exposed, that means that expansion
boards are able to talk directly to the CPU.
2, The DSI connector will allow low-level interfacing with LCDs and other displays.

Revision 2 DIY Add-On Board
3,  The CSI connector will allow camera modules to be added in future.

Step 1: Raspberry Pi single side DIY add-on PCB with 5V/3A buck regulator power supply.

Raspberry Pi – Revision 2  DIY Add-On Board


  1.         5V/3A power-supply
  2.         buffered interface to GPIO pins
  3.         4 button switch
  4.         3 LED [include 1 hardware PWM] – external connectors also available
  5.         1 Relay
  6.         5V logic Level UART interface
  7.         16×2 LCD [74hc595 based]  with back light control option
  8.         SPI ADC MCP3008
  9.         DS1307 with battery backup holder
  10.         24C032 EEPROM
  11.         PCF8591 DAC_ADC
  12.         i2c external connector [3.3v to 5V logic converter included]

Step 2: Block diagram of add-on board

block diagram representation

LM2587 Buck regulator  : 5V/3A power supply

3.3v to 5v level shifter  : ic74HCT125   -single direction

3.3v to 5v level shifter  for i2c  : MOSFET 2N7000 based    -bi directional

24c032 :eeprom

battery:  3V RTC backup battery

DS1307 : i2c based RTC chip

PCF8591: i2c based ADC-DAC chip

4 switch: user input button switches

MCP3008:  SPI based 10-bit Analog-to-Digital Converter

74HC595:  3 wire serial LCD interface

16X2 LCD:    16 character x 2 line  monochrome LCD  [serial interface -74hc595]

LED 1-3 : LED output 3 color LED  [include h/w PWM pin  ]

RELAY:   for  heavy   load application

Step 3: Raspberry Pi Revision 2 26 pin gpio

Raspberry Pi single side DIY add-on PCB with 5V/3A buck regulator power supply  board  designed for   Raspberry Pi Revision 2

Step 4: CircuitRevision 2 DIY Add-On Board Schemetic

circuit diagram list

  1.     gpio relay led connection circuit diagram
  2.     gpio button switch interface circuit diagram
  3.     add-on board and raspberry pi powersupply  circuit diagram
  4.     i2c interface circuit with ds1307 RTC and EEPROM  circuit diagram
  5.     LCD and MCP 3008 interface diagram.

For more detail: Raspberry Pi – Revision 2 DIY Add-On Board

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