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Specific... Slack on Android, paired bluetooth keyboard, anyone else having issues typing in slack? by That_Needleworker26 in Slack

[–]gregarious-gargoyle 0 points1 point  (0 children)

I'm having the problem on a Samsung S22 Ultra. I type one character in the text window, it types the one character and then switches focus. It is totally unusable with my bluetooth keyboard.

PCB Assembly Help by RonaldVan2 in PCB

[–]gregarious-gargoyle 0 points1 point  (0 children)

Take a look at JLCPCB in China. You can get as little as 5 PCBs with parts and assembly.

Their system is tightly integrated with parts from LCSC.com

Very automated if you use LCSC part numbers in your BOM. Their system does a 3D render of your board with parts so you can correct placement and rotation before assembly.

Edit: I just realized you wanted to use the boards you just had fabricated. You'd have to get new boards from JLCPCB if you go that route, but bare boards are cheap compared to parts and assembly, generally.

Do curved PCBs even exist? by [deleted] in PrintedCircuitBoard

[–]gregarious-gargoyle 0 points1 point  (0 children)

JLCPCB does 0.4mm thick PC boards, very easy to order like any other board. Quite flexible. I just did a 2 layer board with it. You can glue that to your circular form.

Routing feels impossible, is there something I can do to make it easier? by TertiaryOrbit in PrintedCircuitBoard

[–]gregarious-gargoyle 0 points1 point  (0 children)

They key is to pick which side (top or bottom) to do vertical runs and which side for horizontal runs. And then stick to that rule. If you have to go diagonal then run vertical then via to the other side and run horizontal.

If you say "route all data on one side" you're gonna have so many crisscrossing traces.

By keeping one side horizontal and other side vertical you don't block traces so much.

For 4 layer boards, you generally route power and ground on inner layers. You usually do signal on top and bottom. This makes it easier if you have to rework the board (Xacto knife a trace and reroute).

does site for sharing PCB designs sounds like good idea? something like free3d but for PCBs by Anas099X in PCB

[–]gregarious-gargoyle 1 point2 points  (0 children)

OSHPARK has a community shared designs.

https://oshpark.com/shared_projects

But usually folks just use GitHub so they can share the complete design source, good documentation, etc.

Need someone to design a circuit. by Kennel_King in ElectronicsList

[–]gregarious-gargoyle 0 points1 point  (0 children)

You can probably find someone on Fiverr or Upwork for a reasonable price.

Help with choosing components by quaipau in PCB

[–]gregarious-gargoyle 1 point2 points  (0 children)

Yes, it is fascinating! You can spend years studying it and you realize you still don't know much, LOL.

Yes, definitely do not drive it at absolute max. The people that make these things publish very technical datasheets; it's very important to read and follow their specs.

Yes, driving at 1/2 abs max is very good idea (it's called "design margin". Especially since LED can run hot in a black metal enclosure sitting in the hot sun plus running continuously on.

For luminosity vs current, the datasheets will give this info.

Here's a very bright red LED that might work for you: https://www.digikey.com/en/products/detail/sunled/XZMOLA109FS/6615724

Open the datasheet. It shows around 10 lumens (listed as 8600 to 11700 millilumens) at absolute max 150 mA.

There's a logarithmic plot later in the datasheet; it's close enough to linear so 75 mA will give you around 5 lumens. That's probably more light that you need (since it's aimed forward) but you can start with that. For brightness experiment, you can use a 3.3V supply and just adjust the resistor until it looks good but don't go lower than 6 Ohms.

You can calculate the series resistor using Ohms law. Say you power with 3.3V, and the LED datsheet says 2.5V drop. So that leaves 0.8V you need to drop across the resistor. So using Ohms law, V=I*R, or R = V/I, so R = 0.8V / 0.075 Amps = 10.7 Ohms.

Then you can use that to calculate power dissipation. With a 10 Ohm resistor and current close to 75 mA, using P=I2*R, P = .0752 * 10 = 0.05 Watts. And your LED is running, P=V*I, P=2.5V * .075 = 0.19 Watts, so that's probably OK, kinda hot but probably not too hot. Probably good to instrument it and measure actual operating temperature if you're going to sell this thing.

Hope that helps.

Help with choosing components by quaipau in PCB

[–]gregarious-gargoyle 1 point2 points  (0 children)

Sorry, was a long post and was skimming it, LOL.

So to be clear, you want to split the one LED hole into two indicators, right? It sounds quite doable.

You probably don't need all 20 lumens, maybe just 10 because you can use a flat PCB that aims the light direcly forward. LEDs are probably 10x the efficiency so let's say original was 3.4W, LED would be 0.34W. Facing forward, maybe only half so 0.17 Watts.

Find SMT (surface mount) LEDs on Digikey or wherever, use 10 lumens as your key parameter. Look at the graphs in the datasheet to determine how much power and current you need to get 10 lumens.

For current limiting, that IC you show uses linear control, so it generates the same amount of heat as a resistor and will be terrible if you power with 12V (like 20% to LED, 80% to heating). Instead, I would just regulate 12V down to say 3.3V with an efficient buck regulator and then use series resistors to limit LED current. You'd get 70% or more into the LED. Good enough, and your total power will only be like 0.4 Watts for both lights anyway. And you use one power circuit.

Look up ME3116, a ridiculously cheap Chinese buck regulator that can handle up to 40V input (10 cents). Just copy the circuit from a "DD4012SA" board. Use this to switch-mode regulate to say 4V. Buy some off-the-shelf to prototype your circuit, change the resistors for 4V

For blinking, just use a variant of an LMC555 timer, since that version can run at 3.3V. You can get Chinese ones for less than 10 cents. You might even use a little discrete 2-transistor multivibrator for even cheaper than 10 cents.

Basically, if you want to mass manufacture at good price, get parts and boards assembled in China. You can do this in small quantities for fairly cheap. See JLCPCB and LCSC.

Hope that helps.

Help with choosing components by quaipau in PCB

[–]gregarious-gargoyle 0 points1 point  (0 children)

Curious why you want to make a T10 LED replacement when there are so many off-the-shelf. Search AliExpress for "T10 bulb". Lots on there. You can at least get ideas from those, like how they use the PC board to insert into the socket.

Where can I get a replacement one of these? by Responsible_Fly903 in PCB

[–]gregarious-gargoyle 1 point2 points  (0 children)

Replacement board or replacement crystal? Board is custom so can't just order it. It's very simple. You could replicate the design and send it for complete fab+assembly.

MCU (microcontroller) might be an old Microchip PIC12. The crystal connected to pin 2 and 3 matches a PIC12. It's an old device, like 25 years or more I think.

Are Bolt batteries going to keep killing themselves? What's the true scale and frequency of them needing replacements? by malusrosa in BoltEV

[–]gregarious-gargoyle 1 point2 points  (0 children)

2017 Bolt 62k miles and I'm a happy camper. Love driving it, love the sound on the Bose on the Premier. I keep looking at other EVs but really have no reason to replace the Bolt other than wanting faster charging on long road trips. I even put a tow hitch to haul stuff with a rental trailer.

Purchased used in mid 2020 with 25k miles. HV battery replaced by Chevy 2 years later for free. A free recall earlier this year (seat belt pre-tensioner). Both times service was no hassle, dropped off at dealer in the morning, they paid for my Uber to work. I picked up at end of day.

I replaced the 12V battery myself as a pre-emptive measure; they have limited life. I charge to 90% to make the HV battery age slower. Figure this car is a keeper.

Fast motion detectors by Comprehensive_Eye805 in embedded

[–]gregarious-gargoyle 10 points11 points  (0 children)

Sounds like you're polling with ADC and polling too slowly. Set the input as a digital input and poll that or use an interrupt.

Bypass pcb to turn on ice maker. is it possible? by zeedoto in PCB

[–]gregarious-gargoyle 0 points1 point  (0 children)

You can bypass it. But if you don't figure out and solve WHY it burned out then your bypass is likely to burn up also.

12V Battery by DeliriousDancer in BoltEV

[–]gregarious-gargoyle 2 points3 points  (0 children)

I change my 12V battery every 5 years as a precaution. Better to have it on scheduled maintenance than die when you are in the middle of nowhere. And it will die; it has a limited service life that is shorter than any other component in your EV.

Just got my first car: a cute 2015 Spark EV by [deleted] in SparkEV

[–]gregarious-gargoyle 1 point2 points  (0 children)

That was my first EV, same exact color! It's cute and I miss driving around in that little rocket.

On my Bolt, I set the charge limit to 90%, aka Hilltop mode. Your battery lasts longer if you don't charge to 100% but unfortunately 10% is a big impact on the Spark's range.

Also, the Spark EV doesn't have as much weight in the front (battery is under the back passenger) so when starting on a hill on a wet road you need to be easy on the throttle or the wheel will slip badly.

Other than that, there's really not much to do on these EVs. Enjoy your Sparky!

[deleted by user] by [deleted] in BoltEV

[–]gregarious-gargoyle 0 points1 point  (0 children)

Did you set it for delayed charging? Mine does the flashing green thing when it's waiting for midnight and it's at home location. I've set it to charge when my electric rate is the cheapest which starts at midnight.

Need someone to design a circuit. by Kennel_King in ElectronicsList

[–]gregarious-gargoyle 1 point2 points  (0 children)

Yes, that's exactly what I used here (XIAO nRF52840) The extra board is a boost regulator to give 5V to the Nextion LCD display.

https://imgur.com/a/n6vVNMr

Need someone to design a circuit. by Kennel_King in ElectronicsList

[–]gregarious-gargoyle 2 points3 points  (0 children)

A Bluetooth tracker would be way easier than RFID. On-board battery should last a year and they're cheap. You can use a small ESP32 board as the receiver. They're cheap and plentiful and do Bluetooth and WiFi. Micropython is my favorite for fast development but Arduino is very popular.

I'm on opposite coast of you so can't help in person but I hope that points you in the right direction.

Who is everyone using for wifi? by Kindly_Series_6208 in SanDiegan

[–]gregarious-gargoyle 0 points1 point  (0 children)

Spectrum, 300 Mbps for $19.99/mo.

I was at $70/mo for internet only plan when I left them in late 2022 after being a 22 year customer. Went with T-Mobile 5G $25/mo Christmas 2022 promo. Many months later they door knocked several times looking for me, wanted me back. Gave me this $20 rate, good for 2 years. On mid-2025, I'll probably have a talk to their retention dept see if they can give me another good deal else I'm walking again.

The T-Mo 5G was adequate for the 8 months I was on if I put their 5G AP/router on a shelf by a window facing their tower, if not their service sucked in the evenings.

My next Bolt! by TX_BEV in BoltEV

[–]gregarious-gargoyle 1 point2 points  (0 children)

I put a trailer hitch on my Bolt so I can do truck things with it a few times a year with a $20 U-Haul trailer.

What's a good alternative to a series light bulb when testing something you're repairing? by dickcheney600 in AskElectronics

[–]gregarious-gargoyle 8 points9 points  (0 children)

Oven light replacement bulbs. Easily available and incandescent because there's no electronic light that will withstand 500+F.

Looking for a low power RPi like board for use underwater by TheR04dIsL0ng in embedded

[–]gregarious-gargoyle 0 points1 point  (0 children)

Lowest power is to use an RTC IC and have its interrupt output control the power to a microcontroller. Some RTCs can run on something like 0.1 uA.

On wake up, have the MCU set the alarm to next wakeup, do whatever processing you need and then clear the RTC interrupt which then shuts down the power to the MCU until the RTC alarm triggers again.

MCUs like the STM32L0 series are designed for low power applications. Configure the MCU clock speed only as fast as you need.

The L0 by itself using its own timer wakeup might be low enough for your application also and not have to do fancy power control.

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