this post was submitted on 19 Mar 2024
69 points (100.0% liked)
What is this thing?
5522 readers
50 users here now
Let us help you identify that mysterious object you’ve found.
Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Okay, I think this is a passive crystal from Seiko-Epson. I've never seen one in this package.
Edit: https://www5.epsondevice.com/en/products/crystal_unit/fc135r.html
Yup looking at the components around and the layout, it does look like a quartz crystal, especially considering it's right next to the microcontroller, and the 2 beige components above are the matching capacitors.
But yeah I've never seen a package with an open window. Maybe it's an ultra high precision that has been tuned with lasers (usually done for patch antennas).
Who would need an ultra high precision quarz on an STM32 processor?
This is being used in a LoRa module (it's a Reyax RYLR896 (which is not great for my purposes ngl)). The STM32 acts as an intermediary between its UART interface and the LoRa module's SPI interface, basically doing some rough translation and some encryption, nothing major. I believe the LoRa stuff has its own crystal, so I would imagine there is no need for an external source.