the Open Source hardware thread

OP
icebags

icebags

Wise Old Owl
Didn't want to hijack the other thread, so continuing here.

So are you working on a project? Audio stuff?
Did you buy a signal generator also?

yah better here....

well, some audio projects alright, making some small amplifiers for experimenting and causal listening purposes. but noh, didn't buy and signal generator, for audio its not very important at this moment, i can just play 1khz sine wave audio files to find where audio is clipping, and how clean it is.

but i have a signal gen in my purchase list, the lab bench ones are rather expensive, and these look better suite the hobby purpose :
AD9850 DDS Signal Generator Module 0 40MHz | eBay
AD9850 DDS DSP Signal Generator Module 0 40MHz Sine Wave FOR Arduinor KG208 | eBay

and yah for audio, made a 2 mobile amps, one with lm386 another with tda2822m : it was difficult to construct just by reading datasheet, had to go through multiple breadboard and veroboard prototypes, then had to watch videos and had to consult the experienced on youtube. finally after some nightmares, they are giving reasonably nice and clean sound. the tda2822m is still giving slight no signal hiss, but that ic has big gain and i m using ic base, so..... (blew up 2x tds2822m to get the 3rd one work nicely).

here are the pics, please pardon the green marker ink on pcb, just had to paint to avoid corrosion. u will probably wont be able to see tracks because of the ink, but i kinda tried my best for a star ground layout. also had to modify those input caps for make them work and for tuning into best suitable bass.

TDA2822M on left and LM386 on right. TDA2822M > LM386 for sound quality any day. but LM386 has sturdier build quality & doesn't fail so easily.

M8F78l3.png



(click to zoom)

also, worked on an another project, to build a charge controller, to charge a 6v lead acid from my 5w solar panel.
and currently working on arduino remote weather station project (well working on it from last winter lol), on 433MHz modules, it works, but i am still working to make it better. will share pics when completes a bit more. :)

and also bought a vire usbfm remote kit @Rs.105/-& and a couple of TDA2003 audio amp ics to build a neat audio listening gear.
 
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Nerevarine

Incarnate
[MENTION=44484]icebags[/MENTION], how good are these amps compared to actual commercial stuff like fiio
I imagine, these enhance noise as well ??
 
OP
icebags

icebags

Wise Old Owl
[MENTION=44484]icebags[/MENTION], how good are these amps compared to actual commercial stuff like fiio
I imagine, these enhance noise as well ??

........... :|

these particular ics were used in 80s or 90s in walkman and portable radio stuff. they cost ~8 - 10/- rupees each, and total building cost <50/-.

noise and stuff depend on how well the circuit boards are build, quality of power supply & greatly on the quality of the speakers used. still, even at best case scenario, these are not exactly hi-fi chips. premium brands like fiio use hi-fi chips and well designed boards, so they are obviously better. but people have done diy with those hi-fi stuff as well, and i guess some of they are happy.

a better comparison would be those frontech / zebronics / logitech / creative stereo speakers < 1000/-. i had one frontech from 2001, that used TEA2025 ship, it gave more o/p power, but the sound quality was inferior.

you may check this, but its a little technical.
 

Nerevarine

Incarnate
[MENTION=44484]icebags[/MENTION]

A couple of my EE friends have decided on building a DAC based

AMB Laboratories
γ1 modular miniature DAC
γ1.5 miniature high-resolution USB DAC + headphone amplifier NEW!
γ2 compact high performance DAC
γ3 high resolution DAC NEW!
γ24 high performance DAC core NEW!

Right now they are confused about the viability of the project, as it may be too difficult in the later stages.. Budget is not a concern as most of the parts, they will get for free.. I was wondering if you had any advice/inputs to give and/or any other good alternative DIY DAC that may be easy enough to do as a small project of duration 3-5months


PS: Budget is not a concern as long as individual parts are ordered from companies that provide free samples via university domain (cirrus logic, wolfson dac, texas instruments etc etc)
 
OP
icebags

icebags

Wise Old Owl
they want to do a readymade project like this ? if they follow that site, then they will end up having the job of assembling the components together. at most they will get to do the board layout and performance analysis.

but i doubt it will be a big project.

not sure if you can really make a discrete project for usb based dac, there are those ready made chips available for that. another kit based solution is here : CS4398 CM102 CS8416IC DAC Kit 192K 24bit SPI I2S Amplifier Board | eBay

an fpga based audio dac project is much more technical, will include programming and designing. again, these are not something new, but still u better ask friends not to copy the online projects, and make use of their own creativity in designing. just take the concepts from web and get in touch with college prof.
 
OP
icebags

icebags

Wise Old Owl
anyone in circle made this ? seems like answer to a lot of headaches. :eek:



made with DVD / CD parts & rails : :eek:

 

RCuber

The Mighty Unkel!!!
Staff member
[MENTION=44484]icebags[/MENTION]

I have seen this first one before, it really comes down to the time you have and sourcing parts can be difficult, or atleast I cant get hold of them.
 

aditiaggarwal

Right off the assembly line
About Open Source Hardware in general and about open source phones in particular.
When someone finds an interesting project they can announce it here.
I think it's a good idea to have a thread dedicated to OSH.
 

TigerKing

Cyborg Agent
I need help in downloading program from Arduino Nano board.
My friend created sketch and uploaded on Arduino Nano.
But after that he formatted that computer and most the sketch.
How do I recover it?
 

Desmond

Destroy Erase Improve
Staff member
Admin
I need help in downloading program from Arduino Nano board.
My friend created sketch and uploaded on Arduino Nano.
But after that he formatted that computer and most the sketch.
How do I recover it?
You want to undelete some files from your PC? How is this relevant to this thread?
 

Desmond

Destroy Erase Improve
Staff member
Admin
That could be the case with a Raspberry Pi, but an Arduino is more of a microcontroller board than a full-fledged computer like a Raspberry Pi.
 
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