Does what it says
For GPS Referenced RF generator 1Hz to 10MHz
GPS is an amazing technology and this board lets you harness it to have a very accurate clock (frequency reference) in your own house.
I liked this device in particular because simply by recompiling the firmware I could select the exact RF frequency in Hz. So I've used it as a frequency reference for a 1960s frequency meter (1MHz), a 1970s quartz watch tester (4.32MHz), and even to create a test signal for said watch tester (1Hz, 5Hz, 360Hz). It is very satisfying to re-tune these old devices' OCXOs.
The author has been responsive to my questions, including when I had some early trouble due to my choice of USB-Serial dongle. Beware that the power requirements of this board are too great to be met by certain "3.3V" USB-Serial adapters, which may not be able to supply a full 70mA of current to the device. When this happens, it appears that the microcontroller repeatedly enters "brown out" mode and not work properly or reprogram from within the Arduino environment. If the green "GPS Power" LED blinks this may be happening to you. In my case, a "5V" USB-serial adapter worked great. (contrary to what another reviewer stated, a USB-serial adapter was not included in my order. The adapters I tried are FTDI-based adapters sold by SparkFun probably 5-8 years ago)
