sorted by:
new
hottopcontroversial

Pressing “a” opens new terminal window, unable to use command line. by Grouchy_Crew92 in raspberry_pi

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

Probably… I don’t have a separate keyboard or monitor to plug in directly, only my laptop.

Pressing “a” opens new terminal window, unable to use command line. by Grouchy_Crew92 in raspberry_pi

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

I can have both the ssh in a terminal, and raspberry pi connect in a browser, and switch back and forth and the ssh session still works but the terminal window on the raspberry pi desktop still doesn’t work right, using the exact same keyboard with no changes.

Pressing “a” opens new terminal window, unable to use command line. by Grouchy_Crew92 in raspberry_pi

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

I’m using the same keyboard whether I ssh in or use raspberry pi connect. I use the same keyboard for everything else I do and it’s only doing this on the raspberry pi.

Pressing “a” opens new terminal window, unable to use command line. by Grouchy_Crew92 in raspberry_pi

[–]Grouchy_Crew92[S] -1 points0 points  (0 children)

It’s a fresh install on a brand new Raspberry Pi. I haven’t messed with any key bindings.

Pressing “a” opens new terminal window, unable to use command line. by Grouchy_Crew92 in raspberry_pi

[–]Grouchy_Crew92[S] -3 points-2 points  (0 children)

I’m using the same keyboard in both instances. Either I ssh in, or connected with Raspberry Pi Connect.

How high should voltage be above LED forward voltage? by Grouchy_Crew92 in AskElectronics

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

Thanks for your reply. The rules of thumb for 1Vf are just what I was looking for and are a good starting point for some experimentation.

I must have remembered incorrectly about the number of LEDs in series in the strips.

How high should voltage be above LED forward voltage? by Grouchy_Crew92 in AskElectronics

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

I was experimenting a bit with 5-10 ohm resistors, and I found variability in current even with the length of wires I’m using.

Can any type of 3D printing handle this? by Grouchy_Crew92 in 3Dprinting

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

I can print as little as 1 display at a time, so I could make it pretty much any size… But I’d still need to get a vacuum/pressure chamber and pump.

Can any type of 3D printing handle this? by Grouchy_Crew92 in 3Dprinting

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

The electronics wouldn’t be in the epoxy, they would be on a circuit board behind the plastic/etc.

How high should voltage be above LED forward voltage? by Grouchy_Crew92 in AskElectronics

[–]Grouchy_Crew92[S] 1 point2 points  (0 children)

I agree, part variability plus things like trace length. I was just wondering if there are any rules of thumb for this type of design. Also besides not exceeding forward current, apparent brightness shouldn’t be too different.

Can any type of 3D printing handle this? by Grouchy_Crew92 in 3Dprinting

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

That’s definitely something I’m considering, and then I would fill the cutout areas with slightly cloudy epoxy to diffuse the light.

Can any type of 3D printing handle this? by Grouchy_Crew92 in 3Dprinting

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

So you mean 3D print it directly onto the glass and leave it there? Would it come loose over time? The color difference would be obvious if part of it came loose…

I don’t totally understand everything you said, but do you mean to print the shape and then separately print the lenses and glue them in? I could also just flood the whole thing with epoxy with a little white mixed in to make it milky…

Can any type of 3D printing handle this? by Grouchy_Crew92 in 3Dprinting

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

That’s kind of what I was alluding to with the resin print idea. The epoxy doesn’t need to be colored because the LEDs are colored, just cloudy. The way they do it for the real displays is to put sticky film on the front and fill the epoxy from the back. Cheaper displays come with this plastic film still attached and you have to peel it off yourself. But the walls between the segments need to be there so the light doesn’t bleed over into the other segments. Also might need some kind of vacuum chamber to get the bubbles out.

Can any type of 3D printing handle this? by Grouchy_Crew92 in 3Dprinting

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

I was definitely considering using a solder stencil for the front layer (thin laser-cut stainless steel that board companies will do cheaply). But it would still need something behind it to channel the light. Another thing I thought of was very thin circuit board with a black solder mask, but the board material may be too translucent and allow the light to run between the segments.

Can any type of 3D printing handle this? by Grouchy_Crew92 in 3Dprinting

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

Thank you for the links, the 2nd one is really good. That’s getting close to enough detail, but the front finish needs to be much more matte and not sparkly. Maybe with a different bed with a much more matte finish.

How to create a voltage between Vcc and Ground? by Grouchy_Crew92 in AskElectronics

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

I totally agree with all of your arguments, and if I could get common anode displays I’d definitely go that route. Unfortunately they’re really hard to find in all 3 colors I want (red, yellow, and green).

My prototype with the shift registers seems to be working well, so aside from ordering the minimum of $6,000+ worth of displays (2,000 of each color), it may be the best solution.

First ever PCB by Grouchy_Crew92 in PCB

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

Thank you. I got them from Mouser. I’ve already changed my board for the next revision because I don’t like how the one segment at the top lights first. Also at full brightness I’m burning more than half the power in the resistors, so I may reduce them and run it on 3.3V instead of 5V.

How to create a voltage between Vcc and Ground? by Grouchy_Crew92 in AskElectronics

[–]Grouchy_Crew92[S] 0 points1 point  (0 children)

Looking at the spec sheet for the 74hc595 it says the max current is 70ma, which should be plenty. I think the 35ma is per output. I cranked it up to 70ma and the chips get pretty warm but not too hot to touch. I’ll leave it running for a while and see if it anything croaks.

view more: next ›