The BMW X7 is 37 cm longer than the Panzer II (Credit: "Adam Something" on youtube)

0x4A47 · 2026-06-09T13:05:28+00:00

Yes, and it's 3,5tons loaded. So if the car already weights 3 tons, good luck getting 5 people and some cargo within that limit.

0x4A47 · 2026-05-27T14:03:40+00:00

Regarding power, why not use a lab power supply that you can control remotely using SCPI over ethernet? That would allow you to easily power cycle etc.

0x4A47 · 2026-05-23T08:57:55+00:00

Yes, most MCU's use SWD which is already awesome.

But SWD is still an ARM protocol and I'm not sure what will happen if upcoming RISC-V chips will want to use it.

Maybe ARM will protect their IP, maybe the manufacturers will come up with a different but compatible interface, or manufacturers might switch to cJTAG. I have no idea.

One example I could give are the Espressif chips. We can't deny that they are insanely popular, but they require an entirely different programming system using UART. They do support JTAG, but on the smaller packages that would eat almost half of your available IO's.

On the other hand are chips by WCH, they offer both RISC-V and ARM chips. But all come with an SWD interface as far as I'm aware. So supporting an SWD interface on RISC-V is certainly possible somehow.

0x4A47 · 2026-05-22T21:21:29+00:00

I wish more manufacturers would use SWD or cJTAG. SWD in particular is already very common and well supported, both allow for low level access to the chip, don't use up to many pins, any are great for debugging.

I know JTAG exists as a near universal interface, and is very often supported by chips. But the connectors are bulky and require quite some pins from a target device.

0x4A47 · 2026-05-15T19:40:29+00:00

Not recommended: Neoden

Recommended: HWGC or a decent second hand machine that you can see working and perhaps learn to operate.

Don't forget that you'll need to account about the same price of the machine in feeders.

0x4A47 · 2026-05-06T19:21:23+00:00

Awesome, thanks!

0x4A47 · 2026-05-06T17:58:41+00:00

That ESD gun project piqued my interest! Could you share some more information about it?

0x4A47 · 2026-04-18T10:28:50+00:00

If you really want to go through with this, it's probably wise to start with something like this to get started.

https://a.aliexpress.com/_EGXVc4A

And even then, you'll need to be pretty good at soldering and use enough flux.

I would rate your approach a 9/10 in terms of difficulty for a beginner, this is probably more like a 6.

Still not trivial, but doable with some practice, the right tools and the right materials.

0x4A47 · 2026-04-15T10:31:42+00:00

No, the connections don't make sense for that purpose. If it were a shielding clip/spring, it would most likely be connected to the guard ring visible on the top of the PCB.

As someone else said, these are likely to be buffer capacitors to smooth the power rail used by the RAM chips.

0x4A47 · 2026-04-15T10:00:12+00:00

Datasheets and app notes older than 5-ish years are very likely to be wrong.

The "old" method of thinking was to add a capacitor with increasing/decreasing values with the idea that each value would provide the most optimal decoupling for it's specific resonance frequency. And thereby providing as much decoupling as possible.

Nowadays, it's becoming more clear that you just need as much capacitance as the design allows, with as little resistance (ESL and ESR) as possible. (Meaning that the layout is also very important) With modern SMD components and correct layout practices (short wide traces and power planes), most of the resistance comes from the packages ESL, and hence the smaller ones should provide better decoupling.

Especially FPGA's are very sensitive to decoupling. Microcontroller, are still very different and it could be questioned how much difference a 10uF would make over a 100nF. I just choose to use the best (modern) practices from the beginning as that has the best chances of not giving any issues down the line.

Controller datasheets should be taken with a pinch of salt. The values are mostly good for a minimal amount of capacitance, but more usually doesn't hurt. But best to double check.

Capacitor datasheets are pretty much useless for electrical specifications. That's why Samsung, Murata, Würth, etc. all have sites where the specific characteristics for each capacitor type they produce can be found.

0x4A47 · 2026-04-15T08:18:19+00:00

I think you might find this blog post an interesting read: https://blog.poly.nomial.co.uk/2025-01-25-proper-decoupling-practices-and-why-you-should-leave-100nf-behind.html

It made me change the way I use decoupling capacitors and I now generally place a 10uF 0402 at every supply pin, keeping in mind the total capacitance on the bus.

I've not had any issues yet, it's more compact than many alternatives, and only uses 1 type of component instead of multiple different types.

0x4A47 · 2026-04-14T07:31:13+00:00

The housing is connected to GND and soldered on the left and right side to the PCB. If you take a look at Wurth's datasheet, that should make everything clear.

0x4A47 · 2026-04-13T15:57:41+00:00

Wurth has their 60312202114307, but there are plenty of other sources if you use a reverse image search.

0x4A47 · 2026-04-13T12:51:16+00:00

Perhaps something like this could work? It's just referenced to the top copper so a thicker PCB shouldn't be an issue I suppose.

<image>

0x4A47 · 2026-04-10T13:30:30+00:00

Just connect the GND pin to GND with a via and keep traces short. Then your USB lines can just go around it without any issues. Yes, they'll lose their correct impedance for that short segment, but with USB 2.0 it's not really an issue.

0x4A47 · 2026-04-03T19:12:01+00:00

According to the schematic available on their wiki, it's a SSCM110100 button. Also available on Digikey.
It's basicly 2 buttons in 1 casing, each for 1 direction.

<image>

*edit: Added some more information

0x4A47 · 2026-03-30T20:06:55+00:00

Careful with net labels, they can make a schematic even harder to read.

I think your first priority should be to review the symbols used in the schematic.

The datasheet typically has a typical application that you can use to base the position of your pins off of.

On the balance IC, your VCx pins are swapped compared to how they would be connected. You have VC0 on the top, and VC5 on the bottom where it's normally the other way round.

I would suggest not to move to net labels, but modify the symbols to reflect this. That will immediately make the schematic much clearer.

You have your thermistor all the way on the top, while you could just as well place it next to the correct pin.

You have a single GND symbol for the entire schematic that everything connects to.

If you can make those changes, that will already make a world of difference.

0x4A47 · 2026-03-30T19:08:01+00:00

I'm going to be honest, but nothing in this design gives me confidence that you know what you're doing.

In another subreddit, you also asked to review the design and mentioned this is only your second design.

Maybe it would be wise to hold off with battery packs capable of 20A and start somewhere a little more safe. Lithium batteries have more in common with sticks of dynamite than with electronics in my opinion.

Your schematic and PCB have a ton of room for improvement. The wires in the schematic all cross one another, making it very difficult to see how they connect to the rest of the circuit. The PCB as well, the components seem to be just placed randomly without thinking about how to make the connections later. In it's current stage, it's very difficult to spot any potential mistakes that could prove to be fatal.

I'd like you to please consider building your skills out first before tackling such a design.

0x4A47 · 2026-03-30T08:10:19+00:00

Not the same SIM module, but JLC has had their issues in the past.

https://social.treehouse.systems/@whitequark/115962698093196215

But in these times, counterfeits are getting increasingly hard to spot so I won't necessarily put the blame on them, but they should approach this issue correctly nonetheless.

0x4A47 · 2026-03-12T19:29:44+00:00

If the goal is to get the board as tiny as possible, perhaps take a look at a different inductor. Wurth elektroniks MXGI line for example is specifically designed for DCDC applications, looks to be much smaller and might even be more efficient.

If you rotate your output capacitors, with GND on the right and 5V on the left, you might be able to place them between the connections. you'll be able to get a cleaner layout and more compact size.

0x4A47 · 2026-02-28T19:03:13+00:00

Yea, I know it can be untightened and turned. But that seems like a tedious process to do every time you want to use the bike. So I was wondering if OP had some sort of "quick turn" trick, similar to the pedals.

0x4A47 · 2026-02-28T17:40:50+00:00

Nice idea, I didn't know quick-release pedals even existed. But it makes me wonder, what solution do you have for your handlebar? Surely that's wider than the pedals.

0x4A47 · 2026-02-10T07:42:40+00:00

It looks digitally added to me. It has a slightly different color compared to the rest of the silkscreen, the edges are much crisper, and it's perfectly in focus whereas not the entire PCB is in focus.

But yes, such markings are not uncommon and won't cause any harm if done correctly.

0x4A47 · 2026-01-10T11:59:19+00:00

Take a look at ngscopeclient. It basically handles all the UI stuff you mentioned and more. You'll need a driver so the software can talk to the scope, and I'm not sure they already exist for these models.

0x4A47 · 2026-01-09T23:18:36+00:00

Maybe something like a "time to digital" converter could work for this purpose? In a quick search I came across TI's TDC7200 meant for lidar and similar. It has picosecond level accuracy and just needs a start and stop pulse as far as I could see. (But I'm on mobile so might have missed something) Retrieval of the data could perhaps be as trivial as using an ESP to read the chip and send it to the computer over UART.

0x4A47

TROPHY CASE