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by MortySmith
Thu Aug 06, 2020 10:52 am
Forum: Graphics, sound and multimedia
Topic: Mixing stereo to mono for pi amp?
Replies: 7
Views: 296

Re: Mixing stereo to mono for pi amp?

to give actual example on what RGJ-PI wrote: Stereo to mono via resistors.jpg this is a mono LM386 audio amp the near side is the stereo input jack on that jack one can see two resistors, each 1K one side to each channel on the jack and the other side of the resistors connected to each other that e...
by MortySmith
Thu Aug 06, 2020 9:15 am
Forum: Graphics, sound and multimedia
Topic: Mixing stereo to mono for pi amp?
Replies: 7
Views: 296

Re: Mixing stereo to mono for pi amp?

You need to sum the outputs of the stereo DAC and feed the output to the input of the channel connected to the speaker. Not sure how easy this is to do in practice if the boards are plugged together but typically you'd take the left and right DAC outputs into say a 1K resistor for each channel. The...
by MortySmith
Thu Aug 06, 2020 8:38 am
Forum: Graphics, sound and multimedia
Topic: Mixing stereo to mono for pi amp?
Replies: 7
Views: 296

Re: Mixing stereo to mono for pi amp?

bump.

Can anyone suggest any circuits or reference material on this?

TiA

M
by MortySmith
Fri Jul 31, 2020 12:29 pm
Forum: Graphics, sound and multimedia
Topic: Mixing stereo to mono for pi amp?
Replies: 7
Views: 296

Mixing stereo to mono for pi amp?

Well.. this is part of a raspberry pi project, but doesn't directly include the pi itself. Since my pi internet radio only has space inside for one speaker, only the right channel is connected to a speaker. Both are connected to the amp. I am using a PCM5102 DAC and PAM8403 amp (the one with a volum...
by MortySmith
Fri Jul 17, 2020 8:44 pm
Forum: Off topic discussion
Topic: Modelling irregular shapes in 3D CAD
Replies: 4
Views: 498

Re: Modelling irregular shapes in 3D CAD

One solution would be to make the outside of the frame a bit over sized, and the go after it with files to make it fit. Yeah that's another solution, although the amount of filing that would need to be done kinda put me off a bit. I'd like to try and get it as close to the final shape before attack...
by MortySmith
Fri Jul 17, 2020 8:38 pm
Forum: Off topic discussion
Topic: Modelling irregular shapes in 3D CAD
Replies: 4
Views: 498

Re: Modelling irregular shapes in 3D CAD

Assuming a 2D drawing is a useful start, how about the following: Tape a coloured background behind the frame; choose the colour to give a good contrast so the edge stands out. Tape a ruler somewhere. Take a high resolution photo. Scale the photo to be 1:1 (or maybe after the next step). Use the cu...
by MortySmith
Fri Jul 17, 2020 8:07 am
Forum: Off topic discussion
Topic: Modelling irregular shapes in 3D CAD
Replies: 4
Views: 498

Modelling irregular shapes in 3D CAD

Hi I was wondering if anyone had any good tips for modelling irregular shapes in a CAD program for 3D printing. The intention is to create a bezel to mount an OLED display into an existing frame. The only problem this is that the hole the bezel would be mounted into isn't truly rectangular (the edge...
by MortySmith
Sat Jun 27, 2020 8:39 pm
Forum: Off topic discussion
Topic: Accurate measuring with calipers
Replies: 4
Views: 633

Re: Accurate measuring with calipers

Practice on a Raspberry Pi if you need it. Since you have the mechanical schematics to compare against in the documentation. https://www.raspberrypi.org/documentation/hardware/raspberrypi/mechanical/README.md Thanks, bensimmo. That's a big help too - I can double-check that my measurements are goin...
by MortySmith
Sat Jun 27, 2020 7:01 pm
Forum: Off topic discussion
Topic: Accurate measuring with calipers
Replies: 4
Views: 633

Re: Accurate measuring with calipers

Two reasonably easy approaches- A) use calipers to measure from edge of board to nearest edge of hole; obviously you want it to be as near as dammit to a perpendicular measurement. Measure inside diameter of hole. Add half the diameter to the first measurement - that’s the distance from edge to cen...
by MortySmith
Sat Jun 27, 2020 6:32 pm
Forum: Off topic discussion
Topic: Accurate measuring with calipers
Replies: 4
Views: 633

Accurate measuring with calipers

Hi, I was wondering if anyone could advise me of the best way to accurately measure the distance from a hole to the edge of a pcb board? I've got a board that I'm making a case for, but am finding it difficult to measure the distances for each of the mounting holes. It's probably me being stupid, bu...
by MortySmith
Fri May 01, 2020 8:12 am
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Yet Another Internet Radio Build (was "Perfboard Strategies")

UPDATE: I've now fixed up the board with the original wiring diagram. The OLED and rotary encoder wiring isn't tested as yet but the amp and DAC appear to work. As pcmanbob suggested, there was a tiny short somewhere which I couldn't track down. Rebuilding the circuit on a new perfboard, with socket...
by MortySmith
Fri Apr 24, 2020 9:11 am
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Yet Another Internet Radio Build (was "Perfboard Strategies")

You must have 1 or more short circuits that have some resistance and so are not a dead short, this is causing high current flow. thanks pcmanbob. I'll check the circuitry before I rebuild it. I must've missed something. I wondered if it was a short in the first place, but all my checking with a mul...
by MortySmith
Wed Apr 22, 2020 10:54 am
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Is this something you are going to mass produce? Or just something for personal use? I ask because there is already something very similar to what your making out there. It's out of stock but I'll post the link anyway. https://shop.pimoroni.com/products/pirate-audio-3w-stereo-amp I have one of the ...
by MortySmith
Wed Apr 22, 2020 10:52 am
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Yet Another Internet Radio Build (was "Perfboard Strategies")

You must have 1 or more short circuits that have some resistance and so are not a dead short, this is causing high current flow. Hmm... any ideas? I've stripped the board and am going to build it again from scratch. I took some inspiration from hippy's post about a SIL header, and I just routed the...
by MortySmith
Wed Apr 22, 2020 8:14 am
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Voltage drops?

Now I have problems with serious voltage drops whenever I plug the board into the pi. The 5v line dips below 3.3V and the 3.3V line goes to 1.8! After a lot of tracing on the perfboard, I couldn't work out the issue. I powered the board with a seperate 5V supply, and the voltage was solid at 5V. Cou...
by MortySmith
Mon Apr 20, 2020 9:12 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

If anyone from the forum admin team is reading this... do you think this should be moved to one of the projects sub-forums? Cheers M Why? If you think your post needs attention the use the report button [!]. A moderator is unlikely to see your post unless you or someone else reports it. Thanks klri...
by MortySmith
Sun Apr 19, 2020 2:26 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

If anyone from the forum admin team is reading this... do you think this should be moved to one of the projects sub-forums?

Cheers
M
by MortySmith
Sun Apr 19, 2020 12:31 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Right... here's a perfboard wiring layout for it.
The diagram on the right is just to show the GND, 5V and 3V3 connections to make it easier for me to wire.
I dropped it here, in case it might come in useful for somebody.
by MortySmith
Sat Apr 18, 2020 5:16 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Ah, OK, then have at it. =) I usually just listen to the one station so all I need is an On Off button and volume up down. I've thought about adding a display to show song title etc but can't find my round 2it. ;) Will do my best! :D Managed to get the OLED working on the prototype, not on perfboar...
by MortySmith
Sat Apr 18, 2020 4:26 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Is this something you are going to mass produce? Or just something for personal use? I ask because there is already something very similar to what your making out there. It's out of stock but I'll post the link anyway. https://shop.pimoroni.com/products/pirate-audio-3w-stereo-amp I have one of the ...
by MortySmith
Sat Apr 18, 2020 2:27 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Right... fresh from a lot of fiddling with Kicad... here's a schematic for the whole project... I think I've got the connections right... The project is based on the internet radio by Bob Rathbone. I did have a previous version that had wires everywhere, and no OLED. And there was no way to control ...
by MortySmith
Sat Apr 18, 2020 12:22 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Not sure if it helps at this point but there are proto hats out there like this, https://www.adafruit.com/product/2310 PiHut still have a few https://thepihut.com/products/adafruit-perma-proto-hat-for-raspberry-pi-no-eeprom Hehe.. they are just down the road from me. Too bad they don't allow you to...
by MortySmith
Sat Apr 18, 2020 12:10 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Not sure if it helps at this point but there are proto hats out there like this, https://www.adafruit.com/product/2310 If you can actually get your hands on one. Adafruit is pretty well shut down. Plated through holes and a layout something like a solderless breadboard. Pimoroni sells them but i th...
by MortySmith
Fri Apr 17, 2020 4:08 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

klricks wrote:
Fri Apr 17, 2020 3:55 pm
The way to reply to a specific post is to use the reply with quote button ["] instead of the [Post Reply] button, then edit out stuff if needed.
Ah okay. Didn't realise that.
Thanks
M
by MortySmith
Fri Apr 17, 2020 3:52 pm
Forum: Other projects
Topic: Yet Another Internet Radio Build (was "Perfboard Strategies")
Replies: 32
Views: 1365

Re: Perfboard strategies

Unfortunately, yes. Turning it into a 20-way SIL makes 16/17 available out of 26, so loses about 40%. How suitable that is depends on what you want to connect, how many and which GPIO you need or want to use. Well, that's still quite an interesting little trick, though. Could certainly be useful fo...

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