si5351 with a raspberry pi

Looking at the schematics for the various si5351 breakout boards, they all seemed rather simple. Usually, it was just the chip, a crystal, and some level shifters. They looked simple enough, so I figured I could throw something together myself. I picked up a few of the si5351 chips from digikey for less than $1 a piece. I had some 25MHz smd crystals around and it turns out, that is all I really needed to get the si5351 working with a raspberry pi. Since the raspberry pi’s GPIO pins are 3.3v, I didn’t need any of the extra level shifting circuitry.

First, I soldered the chips to some MSOP-10 adapter boards.


Since, my crystals were surface mount, I soldered some header pins to the crystal, so I could use it in the breadboard.

Next, I hooked it up to the pi.



After enabling I2C on the pi and checking that it could see the si5351 with i2cdetect, I used this python library to test the setup. It worked.


The next step is to build some sort of transmitter using the pi. Perhaps a QRSS rig.