openQCM (2014)A perfect Arduino shield.
The openQCM proximity electronics is designed as an Arduino Micro shield, mounting a quartz crystal oscillator driver optimized for crystal oscillator applications across a wide frequency range (1–25 MHz).
- Instrument
- openQCM (2014)
- Sheet
- 03 / 05
- Title
- Electronics
- Drawn
- openQCM · Pompeii
The signal path
- U1Quartz crystalheld by two clips
- U2Oscillator driverunbuffered inverter plus inverter, 1–25 MHz
- U3Arduino Microcounts the frequency, reads the I²C temperature sensor
- U4USBto the openQCM software
Stable, low-power, simple.
The oscillator driver incorporates an unbuffered inverter plus an inverter in a single device, optimized for crystal oscillator applications. It is equipped with an I²C temperature sensor to better monitor the temperature dependence of the quartz crystal frequency.
The driver is optimized to work at 3.3 V supply, ±24 mA output current — conditions that ensure high frequency stability and low power consumption. Arduino Micro has a 3.3 V supply from its on-board regulator (max 50 mA draw), so its 3.3 V pin is well-suited to power the oscillator driver. Two clips are embedded to ensure a simple, instantaneous electrical connection of the quartz crystal sensor.
PCB files and firmware
Files served from openqcm.com and the vendors' sites. Open source: see the licence inside each package.