Extremely Accurate Dual Frequency Counter – 175Mhz

Arduino/Adafruit Feather Cortex M4 compatible dual Frequency Counter and RTC

CHF 38.90

Out of stock

Feather M4 Frequency Counter and RTC

DESCRIPTION (dual channel appliance)

You have always wanted an extremely accurate, programmable Feather M4 frequency counter and RTC?

It measures frequencies from 1 Hz up to 175 MHz using dedicated counters with a fantastic accuracy of ±5Hz at measurement frequency 1MHz ( ±5 ppm) and it provides a high-precision RTC clock. The frequency meter is available in two versions featuring 1 or 2 independent measuring channels. It is powered with the 120MHz ATSAMD51J19 Cortex M4 CPU with floating point support, 512KB Flash and 192KB RAM. There is therefore a lot of computing power available to process, analyze or compare measurement results with all possible applications at high speed.

And best of all, it’s Feather M4 compatible. So you know it will work with all FeatherWings! You can use it with the Arduino IDE – and it’s bonkers fast when you do. What a great way to quickly get up and running.

You can stack the FeatherWing 128*64 OLED display on top of it to display the frequency measuring. Or attach an external display like the Adafruit 3.5″ 320×480 Color TFT Touchscreen by using the SPI ports. Or you can use it as an I2C appliance to front end any microcomputer e.g. the raspberry with frequency counter capabilities.

When measuring high frequencies in the MHz range, it is important to use suitable cables with the correct termination in order to avoid reflections and crosstalk. This board is using the PIN Header Connector for the frequency measuring input. Please note that at high frequencies in the MHz range, pin connectors (especially in connection with breadboards) provide less protection than SMA connectors with regard to reflections, parasitic capacitances and crosstalk. For this reason, we recommend that you do not measure frequencies above 50 MHz when using both counters at the same time.

USB cable not included.



Power Pins

Logic Pins

This is the general purpose I/O pin set for the microcontroller. All logic is 3.3V. Nearly all pins can do PWM output. All pins can be interrupt inputs. Please note that some Logic PINs are reserved for the frequency capabilities and are only available to a limited extent for general purpose I/O. For your convenience these ports with a different characteristic compared to the standard Feather M4 Express board are colored blue. Different to the standard Feather M4 the I/O ports do not support I2S (Inter-IC Sound) and Parallel Capture Peripheral.

Analog Pins

Frequency Counter Pins

Other Pins


If you’d like to do more advanced development, trace-debugging, or not use the bootloader, we have the SWD interface exposed. You’ll have to solder to the two SWD/SWCLK pads on the bottom.


We ship the Feather M4 frequency counter and RTC fully tested but without headers attached – this gives you the most flexibility on choosing how to use and configure your Feather. For the header options and how to assemble the header please note the Feather M4 Express product brief.


At this point we refer to the Feather M4 Express product brief too


The Feather M4 frequency counter and RTC is well supported by dedicated software including a library and example code.

The Feather M4 frequency counter and RTC with Arduino sketches requires one library to be installed: Giverny_Feather_M4_FC, which handles the frequency counter. Libraries can be found at: giverny-labs.com/downloads

Run Example Code

We have basic demos that works with the Feather M4 frequency counter and RTC. So please download/compile/upload a sketch. Demo sketches can be found at: giverny-labs.com/downloads


Based on your wishes and requirements, we will be happy to advise you on the configuration and programming of the Frequency Synthesizer & Jitter Cleaner Board or create customer-specific hardware and software solutions.

We look forward to hearing from you at:

Schindellegistrasse 73
8808 Pfäffikon (SZ)