I don't know how many of yall actively keep up with my silly little projects & stuff, but now that I'm making more things worth posting about, I think it's worth mentioning for anyone that might stumble upon them:
I don't support generative AI, and I don't use it in any part of anything I make!
Wrote up a little blog post on ko-fi since I haven't posted there in a while!
In this one, I go over some of the major changes I made to the second revision of the "Meshlet" PCB I designed for use with Meshtastic, and what warranted a full redesign after the first attempt.
ko-fi.com/post/Meshlet...
Don-chan from Taiko no Tatsujin flying in the clear sky above a flat landscape with overgrown grass, trees and a river
what a lovely da- WOAHHH giant don in the sky
I ported Super Monkey Ball to a website.
You can access it in the replies.
(or just type what you see in the video, I'm not your boss.)
Major progress! I did have to cheat a bit using the internal layers to route some power traces, but that should be fine, I think. All the important stuff is routed over unbroken ground. But this makes my first real 4-layer design! Test batch coming soon, after I make the silkscreen look nice 💪
This is a very early set of screenshots, and it's nowhere near done. Probably gonna be another 1-2 months before I can even think about testing it. But it's very satisfying learning from the prototyping process, and actually fixing my silly mistakes :) I got rid of over a dozen unnecessary parts!
Top-down view of an unfinished PCB, featuring several nicely laid out jumpers and LEDs, alongside many neatly organized chips. Alright, maybe not *that* neatly organized. But it's plenty better than the last one.
A screenshot of the back side of an unfinished PCB. There are footprints visible for a battery connector, power input, LoRa radio module, and Raspberry Pi RM2 wifi module. The battery connector is pointing away from the edge of the board, instead of towards the outside, to allow for easier and slimmer case designs.
A screenshot of the unfinished PCB being routed. It's a mess, and there are several light blue lines connecting pins that have not yet been routed. It'll look better soon! I promise!
Meshlet v2 on the way!!
I managed to shrink down the PCB plenty without losing features! Just no more unnecessary parts for debugging or testing (or because I misread the datasheet lol oops)
This board clocks in at only 42*32mm -- and it shouldn't die as soon as the wifi module tries to transmit!
Meet Pebble Round 2 - the most stylish Pebble ever
$199 on rePebble.com
A photo of a Meshtastic node sitting atop a wooden surface. It's a basic device, in a nondescript black 3D printed shell. It has an antenna sticking out the upper left corner, and a mechanical keyboard switch (Kailh Choc red, in case you're curious) on the lower left corner. There's a screen in the middle displaying some information about the node. Above the screen, the word "MESHLET" is engraved into the shell.
There's something extra satisfying about designing your own hardware. Not just the 3D printed shell, but the electronics inside, too. Like. I *made* that!! For once I didn't just put an off-the-shelf board into a neat little case!!
Now that I know what needs revising, I can get started on v2 🥳
If this one works out, I'm thinking of rebuilding the PCB from scratch on a 4-layer PCB. I've only ever worked with 2 layer boards before so if anyone has any tips/tricks/resources it would be a big help!
A screenshot of the revised PCB in KiCAD's 3D viewer. The board is a black rectangle with rounded corners, about half the size of a credit card, with gold contacts for the components & solder points. It's pretty messy, but many of the decorative details previously present have been replaced with additional components.
For v0.2, I added dedicated LDOs for the RP2350, LoRa radio, and all the smaller peripherals - 3 in total! The WiFi module now draws power directly from the battery chip's output. Last but certainly not least, I added a bunch of decoupling caps that I somehow managed to miss the first time around.
I'm not sure what I was thinking, but it was probably "yeah 200mA will be enough" before I fell victim to the feature creep. The WiFi radio alone draws ~270mA in bursts whenever it tries to trasmit, lol.
Got some updates after a day of testing!
Things that work:
- LiPo charging via both inputs!
- Solar charging, even with those tiny cheap 5v panels!
- BME280 temp/etc sensor
- 3 channel power monitoring
- WiFi!
Things that don't:
- Trying to use a single 200mA 3v3 LDO to power everything.
- Oops.
Signs of life!! Just waiting on the radio modules...
That looks pretty sweet! What do you plan to do with it?
Sounds neat! I wanted to move away from the esp32 because of its high power consumption - it's not very friendly with solar power, and I want to be able to leave these unattended for extended periods lol.
Would love to see how yours turns out! What kinda RF stuff did you have in mind aside from FM?
Almost there... 👀
👀
Still holding out hope for more than like 3 SMX cabs in Canada 😭 I hope this means being another step closer!
Yoooooo Honda Fit mentioned 🔥
This is incredible!! The OS being open source was cool enough, I can't wait to dig through this
I'm pleased to share the schematic AND Kicad project for Pebble 2 Duo - useful if you are have fun hacking! github.com/coredevices/...
gonna infect you with this
Jumpscared by Raw Thrills game chairs on the tl while taking a break at work (an arcade) after just having worked on the Raw Thrills games with the chairs
The PCB from the first photo, but with the magnet sensor chip removed, sitting beside the board. It's an AS5600 IC, which is a programmable hall effect sensor that can communicate over I2C, as well as output an analog or PWM signal.
A zoomed in photo of the board with some scribbling on it. I've drawn a blue mark on the pin I want to identify, with a line leading to a circle, representing a trace going to a via, which grounds the pin. There's a red line and a small drawing of some scissors, indicating that I've cut that trace.
Another photo of the PCB. The chip has been reattached, and a brown wire has been soldered between two of the pins, pulling it high to positive voltage, instead of low to ground.
Obviously, you look up the sensor datasheet, do some light reverse engineering on the PCB, snip some traces, and pull the "DIR" pin listed in the datasheet high to reverse the output direction!
Shoutouts to the manufacturer for not laser etching the IC part numbers out :)
Two potentiometers from a Raw Thrills "Snowboarder" game. The one on the left is new. The one on the right is also new, but has been cracked open, and the parts are laying on the table. There's a small circuit board with a magnet sensing chip, a green insulating plastic piece, and a magnet.
We have some games at work with bad steering potentiometeers. The old ones are discontinued, and the output range on the new model is backwards, which means the steering is also backwards.
Turns out, they're not real potentiometers. They're hall effect sensors in disguise. How do you fix this...?
I've been bedridden for the last 10 months for medical reasons, and I'm still about 1000$ behind on being able to pay for my car and storage. I'm sorry to keep asking, but if you could send a couple dollars, it'd really help.
ko-fi.com/fooneturing
I'll absolutely post updates once I know for sure!
Oh, I forgot to mention -- like most of my other projects, this thing is open source! Though the repo itself currently still needs some work, you can find all the design files & BOM at github.com/dj505/meshlet :)
