FenTrac
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This project is a converter board to connect an Arduino shield that requires 5volt logic levels to a Raspberry Pi.
The board converts logic levels between 3.3volts and 5volts. It uses Mosfet transistors do the conversion and automatically respond as inputs or outputs.
The Raspberry Pi will be damaged if 5 volt logic levels are connected to it's GPIO pins. Great care is required to assure that everything is working correctly before attaching the board to a Raspberry Pi.
20 GPIO pins from the pi are connected to headers arranged in Arduino pattern so a shield can be plugged into the co.verter board.
The board requires an external regulated 5volt DC power supply. There is a 3.3volt regulator on the board itself. Power is not connected to the Raspberry Pi, only ground. The Raspberry Pi has limited output current so it's power is not used to power the shield.
No Arduino or Atmega processor is used in the design. Software to run the shield is written as a Pi program, running on the raspberry Pi. It cannot use Arduino Sketches or code.
The connection of the GPIO pins to the headers is arbitrary. The schematic shows connections that consider some of the possible functionality of the GPIO pins, such as serial Rx andTX, SPI, and PWM.
schematic of the board
using a TFT shield
completed board
The board converts logic levels between 3.3volts and 5volts. It uses Mosfet transistors do the conversion and automatically respond as inputs or outputs.
The Raspberry Pi will be damaged if 5 volt logic levels are connected to it's GPIO pins. Great care is required to assure that everything is working correctly before attaching the board to a Raspberry Pi.
20 GPIO pins from the pi are connected to headers arranged in Arduino pattern so a shield can be plugged into the co.verter board.
The board requires an external regulated 5volt DC power supply. There is a 3.3volt regulator on the board itself. Power is not connected to the Raspberry Pi, only ground. The Raspberry Pi has limited output current so it's power is not used to power the shield.
No Arduino or Atmega processor is used in the design. Software to run the shield is written as a Pi program, running on the raspberry Pi. It cannot use Arduino Sketches or code.
The connection of the GPIO pins to the headers is arbitrary. The schematic shows connections that consider some of the possible functionality of the GPIO pins, such as serial Rx andTX, SPI, and PWM.
schematic of the board
using a TFT shield
completed board