Electronics > Beginners
The "I made this!" thread - Beginners achievements with pride.
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Jwillis:
Not as advanced as some of you folks but I have a couple that I'm proud of.
The first is an adjustable attenuator.That thing on the end is a 50 ohm terminator.It tests within 1 ohm so far but I haven't tested the decibel attenuation just yet.
The other is a picture of a coil winder I modified to handle longer coils.Yes its a Tesla coil.Just a few nuts and a piece of ready rod and a little sheet steel .Still has some bugs but its doing what I need it to.
Peabody:

--- Quote from: KL27x on February 24, 2018, 05:28:56 am ---
--- Quote ---and a stepup boost converter to take the 3.7V LIPO output up to around 8.2V.  It turns out there's room for all that inside the case.  Everyone who does this does it a bit differently, but the pics below show where I put things, and how I connected them.
--- End quote ---
That is a fun project, for sure.

I did something similar with a pocket scope. If you examine the PCB for awhile, maybe you can figure out where/what are the other power rails. Surely, most of the power drawn in this scope is either 3.3V or 5V. You could potentially increase your battery life by using dedicated boost for the 9V rail, and a second circuit connected directly to the main rail. For instance, on my particular pocket scope the 5V rail was achieved with a linear regulator, so that extra 4V would be a complete waste. I removed the 7805 from the board, entirely.

Also, you might examine the input protection on the 9V input. There may be a diode drop you could bypass.   

I have to admit I have no use for a pocket scope, though. I have a hard enough time using a real scope with real controls. These pocket scope have to come along a bit further for me to be able to do anything with them. :)

--- End quote ---

There is a diode on the 9V input, which I assume is for reverse polarity protection.  Then the resulting 8.3V goes to a 3.3V linear regulator which powers the entire digital board - the processor, the display, etc.  So that's quite a drop.  But the 8.3V is also converted to -8.3V with an ICL7660, and then those go through a 78L05 and 79L05 to produce regulated +/- 5V for the analog board opamps.  I assume the design priority here was low cost and reasonable performance, not low power consumption.
BrianHG:
I completely re-done my free-for-all Subwoff sub-woofer project just now.  PCBWay.com quotes 5$us for 10 PCBs + shipping with 2-3 day delivery.

For anyone who want's to build their own, the full project page with cad files is here:
https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/
Hextejas:
If I want to build this beast, which files do I send to the MFG ?
Howardlong:

--- Quote from: chris_leyson on February 23, 2018, 11:54:45 pm ---@paulca Totally agree, for what you get I think the price is very fair, I recently gave up trying to write code for a PIC24 and found I could get things done tens times faster with a UNO and the Arduino compiler. A PIC24 processor was a bit of overkill whereas an ATMega328 did the job nicely. I haven't used an Atmel processor in a long time but going through the datasheets I now prefer them over PICs. The other advantage of AVR over PIC is that I get them in much smaller QFN packages if I'm really stuck for space.

There are a lot of very good Arduino tutorials and libraries and adding on your own hardware is easy. To be honest I've been far too sceptical about the Arduino platform for far too long and now that I've been playing with them I really like them.

--- End quote ---

Horses for courses, I agree with your sentiments, Arduino is great to get stuff prototyped and when performance isn't key: that's the compromise, portable code, but not always the best performing. A big problem with PICs is that even within the same family there are significant differences between peripherals. I don't think the code generators help in anything but the short term, you still need to know how the peripherals work.

I've lived PICs for >20 years so I find them more natural to use than Arduino, but I quite often go to Arduino if I'm looking for some code to drive a particular external device like an LCD screen or accelerometer for example, and port it. The code base from the Arduino community is enormous.

Not sure which PIC24 you're using, but the majority are available in QFN.
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