Fine Grain Solutions

Hardware design | Firmware development | DFM consulting

[Fine Grain Solutions @fine_grain_sol]

I was not expecting this explosion of questions (thanks @i2cjak) about this board so I will do my best to answer them all here.

The RP-PoE-Pico is a (somewhat) pin compatible RP2040 board with Ethernet and PoE. The board is effectively a Pico footprint with an extension for the PoE side.

The goal is for it to be reflowable so it can be dropped onto any board to add PoE and an MCU without any headache, it will also have the normal header rows for you to use on a breadboard or Pico carrier boards.

NOTE: this is non-isolated so you cannot plug in this board to your PC and PoE power at the same time, Ethernet+USB is fine but not PoE. I am working on an isolated version.

And of course, we added a reset button, USB-C, and a Qwiic because I love my customers.

If you just want a PoE powered Pico device check out the hub which is currently shipping for its initial testing: https://t.co/CBuMZMZ5z4

Pico listing is here for pre-production reservations: https://t.co/sA6uFiVIAG

[Fine Grain Solutions @fine_grain_sol]

@supercollider_x KiCad, you can make anything your heart desires even if it’s unmanufactureable and a waste of time

[Fine Grain Solutions @fine_grain_sol]

What other form factors should get PoE while I am on a roll? @adafruit Feather?

I am also considering a standard US single gang outlet box, but not sure what I would put on the front. Buttons? Screen? Sensors?

[Fine Grain Solutions @fine_grain_sol]

In honor of @eevblog (one of my long time idols) reposting me, I will be doing a totally unscripted video of the bring up of my next board

I’ll show up unprepared and just figure it out on camera

No script, no fear, all opinion, as they say

[Fine Grain Solutions @fine_grain_sol]

@eevblog First batch is already out the door, told the customers to find some reverse cables

[Fine Grain Solutions @fine_grain_sol]

Hours of layout and routing, certified bummer moment

[Fine Grain Solutions @fine_grain_sol]

ABORT DO NOT DO THIS

I am destitute and I will never financially recover

[Fine Grain Solutions @fine_grain_sol]

Reminder to take your wife to IKEA more often

[Fine Grain Solutions @fine_grain_sol]

Status update on this, playing with multiple models for the RE effort of the Broadcom firmware blobs

Trying to get DeepSeek to grind out easy labels then Opus to review and knock out any blockers

Still need to refine this approach to prevent a ton of dead time like I had today

[Fine Grain Solutions @fine_grain_sol]

I hate that Raspberry Pi 4 WiFi requires a closed source firmware blob. I intend to fix this, updates to follow

[Fine Grain Solutions @fine_grain_sol]

@chrisayad0 Hopefully it’s not necessary but I may need to include stuff like DB9 cables or a USB to RS232 adapter. Really depends on what the average user would need to get it to work

[Fine Grain Solutions @fine_grain_sol]

I haven't really posted about this one, but this board is for interfacing with BMW ADS protocol automotive modules.

A couple classes of racing use older cars with pre-OBD2 ports, and this lets you talk to their modules over standard RS232. It helps with things like bleeding brakes by triggering the ABS.

It's currently in testing with a driver. Once he's validated it and we've figured out what else other drivers need in the box, I'll list it for sale on the site. No price yet because I still need to nail down cable suppliers.

https://t.co/ZMXLleSHdQ

[Fine Grain Solutions @fine_grain_sol]

@observie Another tip, grid or regularly placed stitch vias can create harmonics. It’s better to distribute them randomly using a noise pattern.

This does not apply to edge stitching which is more of a wall around the edge of the board for edge fired emissions

[Fine Grain Solutions @fine_grain_sol]

@realwillreil VOCs fear this man

[Fine Grain Solutions @fine_grain_sol]

@RealAidenCook Leadership failure

[Fine Grain Solutions @fine_grain_sol]

@Xaraphim How did I miss this? Looks like they lifted the design from Formlabs. I need one asap

[Fine Grain Solutions @fine_grain_sol]

@shiba_8ro In America, that is just a normal car

[Fine Grain Solutions @fine_grain_sol]

@NotEnoughEntrop Check out the listing for dimensions, it’s pretty much nailed down to where it’ll be in production. Honestly smaller than I thought I’d be able to make it

[Fine Grain Solutions @fine_grain_sol]

@Dirdmaster @i2cjak It’s a script that works off of the 3D model export from KiCad and then you pick which component gets a highlight

I’ll DM you the script files if you are interested but it is AI generated so I literally have no idea how it works under the hood

[Fine Grain Solutions @fine_grain_sol]

I was not expecting this explosion of questions (thanks @i2cjak) about this board so I will do my best to answer them all here.

The RP-PoE-Pico is a (somewhat) pin compatible RP2040 board with Ethernet and PoE. The board is effectively a Pico footprint with an extension for the PoE side.

The goal is for it to be reflowable so it can be dropped onto any board to add PoE and an MCU without any headache, it will also have the normal header rows for you to use on a breadboard or Pico carrier boards.

NOTE: this is non-isolated so you cannot plug in this board to your PC and PoE power at the same time, Ethernet+USB is fine but not PoE. I am working on an isolated version.

And of course, we added a reset button, USB-C, and a Qwiic because I love my customers.

If you just want a PoE powered Pico device check out the hub which is currently shipping for its initial testing: https://t.co/CBuMZMZ5z4

Pico listing is here for pre-production reservations: https://t.co/sA6uFiVIAG

[Fine Grain Solutions @fine_grain_sol]

When working with boards like this (with two power supplies) you should really consider using protection.

Check out the @amembedded isolated hub: https://t.co/lmu9lIYh1X

[Fine Grain Solutions @fine_grain_sol]

@Dirdmaster @i2cjak I'd love a tribute that you sell and give me no credit for, feel free to copy my website too

[Fine Grain Solutions @fine_grain_sol]

@furt_tech @i2cjak https://t.co/b4z7YzlaMH

[Fine Grain Solutions @fine_grain_sol]

I was not expecting this explosion of questions (thanks @i2cjak) about this board so I will do my best to answer them all here.

The RP-PoE-Pico is a (somewhat) pin compatible RP2040 board with Ethernet and PoE. The board is effectively a Pico footprint with an extension for the PoE side.

The goal is for it to be reflowable so it can be dropped onto any board to add PoE and an MCU without any headache, it will also have the normal header rows for you to use on a breadboard or Pico carrier boards.

NOTE: this is non-isolated so you cannot plug in this board to your PC and PoE power at the same time, Ethernet+USB is fine but not PoE. I am working on an isolated version.

And of course, we added a reset button, USB-C, and a Qwiic because I love my customers.

If you just want a PoE powered Pico device check out the hub which is currently shipping for its initial testing: https://t.co/CBuMZMZ5z4

Pico listing is here for pre-production reservations: https://t.co/sA6uFiVIAG