USB Pressure Sensor

Overview

There appears to be an absence of low-cost USB-based pressure sensors. The basic idea is to provide a PCB supporting 1 to 8 MPX2202xP sensors (differential, gauge or absolute) accessible via a USB bus. Ideally the sensor will be USB powered, but if the total current draw is greater than 100ma (500ma?) an external power supply will be required. If powered from USB, a 5V to 16V boost converter will be used. A PIC18F14K50 will be the controller, and directly supports USB (no FTDI-type part needed). If sufficient I/O remain, perhaps an LED or relay will be provided also.

Parts

• PIC18F14K50
  • USB 2.0 Full Speed
  • A/D (9 channels, 10 bits)
  • 16K FLASH
  • 768 bytes RAM
  • 256 bytes EEPROM
• MPX2202 (Differential, Gauge or Absolute)
  • 0-200Kpa (0-39 PSI)
  • 0-40mv output
  • 16V supply
• USB A-connector (or micro-USB?)
• LT3464 Boost Converter

Documents & Images

• PIC18F14K50 (Product Page)
• MPX2202 (Datasheet)
• A Simple Sensor Interface Amplifier (Application Note)
• Understanding Pressure and Pressure Measurement (Application Note)
• Machined Electromechanical Sensors for Automotive Applications (Application Note)
• LT3464 Boost Converter