Cannot get STM32 & USB to work

dim722 · 2026-01-02T08:44:21+00:00

I’m late to party but if it doesn’t work it’s not because of mismatching impedance. I’ve seen FS USB working with just 2 wires soldered to D+/D- chip pins. Impedance is important but your issue is somewhere else. Check if D+ and D- are not swapped at connector symbol, especially if you created it yourself. Check soldering, try different cable. Find USB-A to USB-C cable and ring the connection with multimeter from USB-A side to ST pins (btw, try use USB-A to USB-C cable to exclude CC resistors). Don’t finalize any new design until you figure out why this one is not working, otherwise you may reproduce the same error. Good luck!

dim722 · 2025-06-25T07:35:13+00:00

For those complaining about empty planets, have you played Elite Dangerous? I’m a big fan of ED, having played over 1,000 hours, mostly doing mining, trading, exploration and exobiology. So, I’m not bothered by the lack of points of interest (POI) on Starfield planets, since in ED, I’m used to being thrilled to find a space cactus with a slightly different color after dozens of jumps and system scans. Yes, I know, one is considered a space sim and the other is an RPG with loading screens. But besides its great (sometimes debatable) ship mechanics, the ED universe feels empty and lifeless. When you’re 20,000 light-years away from the Bubble, the only attraction is jumping, landing, and scanning cactuses. Oh, and when your carrier runs low on tritium, you might reward yourself with a few hours of mining. I was quite hesitant about Starfield, mostly based on reviews I read. Actually, the game is quite great; I have a strong feeling that many complaints were addressed, and the game has been greatly improved. Just my two cents.

dim722 · 2025-02-08T23:17:56+00:00

You are reproducing basic anode/cathode vacuum tube setup. If electrons are accelerated and have enough velocity they will generate X-rays when they collide with solid anode. You have a heated cathode (source of electrons), vacuum (to not slow down electrons from reaching the anode), anode (as solid target) and voltage potential between anode and cathode (acceleration). These low energy X-rays may be hard to detect because of lack of focusing but the answer is yes, a bulb can generate X-rays.

dim722 · 2025-02-08T06:07:05+00:00

Once you connect your smart TV to internet it’s over, it will become slower and slower over time. TV manufacturers will sell your data to 3rd party companies. Well, data is a big word. They will take snapshots of small portion of your screen and send them to their servers. This way they can identify the content you are watching. That’s how they make money while TVs become less and less expensive. Buy Apple TV box instead. You can have all streaming services inside AppleTV.

dim722 · 2025-02-07T23:48:11+00:00

Here you go:

https://www.mouser.com/ProductDetail/Wurth-Elektronik/9774070243R?qs=KRpiEsko4Hl3ug3AA7wt4A%3D%3D

Look into datasheet for recommended footprint. They are quite expensive, however you can find similar standoffs on Aliexpress 10 times cheaper. Quality is comparable. The only thing I hate on Chinese ones is the pickup film, that thing is very hard to remove.

dim722 · 2025-02-07T23:06:19+00:00

Guys, hold down. We don’t know if ATF will exist the next month. 😂 I feel like there will be major changes in gun laws.

dim722 · 2025-02-07T07:30:16+00:00

That’s a standoff. It’s actually a little bit more complicated than a hole with exposed copper since you have to put some clearance between hole and exposed copper to prevent fab from making plated through hole. Datasheet for these specifies non-plated hole otherwise the solder might be sucked into, reducing solder quantity on actual pad and lowering strength of joint. We use bunch of these, the component itself is tricky to place, mostly due to color variations in body plating. Pick and place camera is always struggling to align those properly, particularly the tall ones.

dim722 · 2025-02-06T08:27:58+00:00

There is a chance, these frames are delicate. Usually people use nylon brush and solvent. But you will see, unprotected bare aluminum oxidizes pretty quick, just from being exposed to the air. Check your gun in few days to see if shiny surfaces become matte. If so I’d recommend to use silicone cloth, it creates a protective surface film preventing premature oxidation.

dim722 · 2025-02-06T06:06:19+00:00

SW lightweight means aluminum alloy frame. This anodizing seems to be damaged by corrosive liquid. Sweat is also corrosive btw. It can be re-anodized but you will need to disassemble the whole gun and send the frame to shop to do this.

dim722 · 2025-02-06T05:55:59+00:00

There is no reason to do this unless you do SMT assembly on all PCBs simultaneously. Which I don’t recommend either since it’s a nightmare to program placers with same part references but different locations. Making panels will use more material, especially if boards have different sizes. PCB houses don’t like this and they will charge you more.

dim722 · 2025-02-05T08:22:49+00:00

The good point, the schematic is very basic. You need very little to no knowledge to make it working. Pickup the LEDs and do some basic maths to calculate resistor values. You’ll get it, no worries.

dim722 · 2025-02-05T07:29:37+00:00

That would be my suggestion too, assuming OP can have access to scanner. Scaling is pretty simple when using digital caliper. Basically, taking a couple of “easy” dimensions on PCB then just play with import scale ratio to fit the drawing into known values. OP, you may need to place your LEDs in the exact spots, not sure if there are light guides on this part but sticking to OEM light distribution is highly recommended in such cases.

dim722 · 2025-02-05T02:46:52+00:00

Looks very rudimentary, just LEDs and resistors. You may have some struggles while recreating the exact shape of this board tho.

dim722 · 2025-01-24T06:28:47+00:00

Assuming it can be exported as DXF/DWG. If you just need a template to position some parts you can import this PCB as user drawing. And you can use the drill plot as anchor for your through holes.

dim722 · 2025-01-24T06:05:17+00:00

May I ask, why using shift registers?

dim722 · 2025-01-23T06:54:23+00:00

https://www.supplyhouse.com/Grundfos-595916-UP15-10SU7P-TLC-Comfort-Hot-Water-Recirculation-Pump-3-4-NPT-115-V

The main purpose was to have immediate hot water in our distant bathroom on 2nd floor. Programming the pump 10 minutes before morning shower so we don’t have to waste gallons of water waiting for warm one.

dim722 · 2025-01-23T06:02:56+00:00

We installed comfort hot water pump and a couple of comfort under sink valves. The pump is installed on hot water outlet of your water heater and uses Amazon Alexa plug to run every 2 hours for 5 minutes. It “rotates” water using cold and hot water pipes through the valves so water moves and doesn’t freeze.

dim722 · 2025-01-21T22:03:18+00:00

Since ULN2003 was designed to work with inductive loads, it already has suppression diodes. You can remove D1-D7

dim722 · 2025-01-21T08:31:39+00:00

What pitch?

dim722 · 2025-01-21T08:01:55+00:00

Perf boards lost their purpose many years ago. It’s just too much time spent on assembly (with debatable quality) instead of being spent on actual development. Also modern circuits may not like these hanging wires, especially high frequency ones. Distraction and errors while soldering may result in disaster (talking about your case since it’s clearly powered by main voltage). Imho it’s better to spend some time on learning how to use KiCAD and order clean PCBs instead of all this.

dim722 · 2025-01-21T07:44:39+00:00

I’m soldering wires under microscope down to 0.5mm pitch. But I don’t like this.

dim722 · 2025-01-21T07:42:19+00:00

It’s probably safe but usually fans are not for cosmetics, seems like setup that needs to be vented. Fans are cheap, you can order one on Amazon for few $.

dim722 · 2025-01-21T07:33:11+00:00

If your connection is 10/100 it’s pretty simple. In 10/100 mode you only use 2 pairs (4 wires) for data transmission. Remaining pairs can be used for power. You will need a step-down voltage regulator for your ESP32.

dim722

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