Ok, its comming along nicely.
So the idea is an EASY DIRECT replacment for the raduino with the option of 3 extra I2C devices.
Minimal soldering, NO SMD if you dont want to.
The SI5351 is implemented via a common breakout board.
So Solder on your headers, 7805, 3 capacitors, 1 recommended resistor(cut the joining trace) and your RV1 for the backlight, or convert to i2c LCD backpack and free up 6 digital IOs.
Please have a look at the board design and let me know if you see any issues...
I will order 30 boards and when they arive, test a few, and then the rest will be sold at cost price + postage: Maybe $5 all up? Ill have to see...