Show Posts
Pages: [1] 2
1  Using Arduino / Project Guidance / 4 RCA -> 1 RCA usb controllable video & audio switch on: October 12, 2013, 08:59:54 am

i want to make a 4 video&audio input to one video&audio RCA output switcher
controllable with USB or RS-232

option : it would be nice if a LED on top of each input would tell me visually which one is currently on the output

the closest i found is the
but it ships for 440 USD, it does not has the right connectors and it would be so much fun to actually build it instead

i thought i could use an arduino as it seems well suited for the job and it's been a while it's forgotten somewhere in a cupboard
i remember i used it for some code, a couple LEDs and a keyboard matrix, but i didn't go further back then.

it seems those connectors should work
i just need to buy 5 of them (4 inputs + 1 input)
i guess an arduino shield for playing around would help too
i guess i should be using relays too but i am a complete noobs when it comes to electronics

Does it sound feasable ?
how should i get started ?

2  Using Arduino / Project Guidance / usb controllable analog video switch 2 -> 1 on: January 27, 2013, 02:56:09 pm

i want to build a video switch
basically it would have two analog video/audio input (i'm thinking of the typical yellow/white/red cables)
and one video/audio output (same format)

so in = 6 wires
    out = 3 wires

then from host PC i would need to send requests on the USB wire such as
 * connect video intput 1 to video output
 * connect audio Left input 1 to audio left output
 * connect video intput 2 to video output

(and get command result back)

i don't need the arduino to do anything on the video/audio stream
as an option it would be nice to know if i have anything at all on a given input cable (maybe detect voltage, i don't know)

i'm terrible when it comes to hardware (software is ok)
sorry if this sounds obvious, but is this even doable with an arduino ?

3  Using Arduino / Project Guidance / automatically pressing a physical button / switch on: January 17, 2012, 04:51:57 pm
sorry if the question has been asked a zillion times, but i am consufed with what i find. maybe i am not using the right words.

i want to use an arduino to automate the pressing of a few buttons. basically, i need it to press a some tiny physical button. it does not require a lot of power here. i'm talking about a button like you can find on a tv remote, or a mouse. except the button (switch?) wouldn't move at all (like fixed to a wall or a table)
it's like something you are normally expected to press with a human finger without appling force.
but sometimes the button is very tiny (think the reset button that you are supposed to click with a pen, that you cant press by accident)

i was thinking of building a fake finger, and then controlling it with my arduino board.
maybe moving with a servo or a motor, or an electro magnet, or a spring, or an elastic, i dont know what exists and what is appropriate.

sometimes i need the keep pressing on the button for a couple seconds instead of just clicking.

i don't need to press it repeatedly or quickly.
i would rather have a solution that consumes little electric power (i dont plan to use batteries, but it's no reason to waste energy)
i'm fine if my "fake finger" needs a few seconds recharging (to go back to its initial position for instance)
i'm fine if my "fake finger" needs one or two seconds to do its job (no need to be faster)
i would rather avoid a solution that would need to replace components every week or so

what are the best options ? what would you recommend here ? should i use a servo ( ? wouldn't a translation movement be more appropriate instead of a rotation mecanism ?

i dont know the vocabulary here. i'm more an IT guy than a mecanical guy but it's fun to learn smiley

4  Topics / Device Hacking / Re: anyone knows a decent affordable logical analyzer ? on: October 23, 2011, 02:43:37 pm
Open Vizla on paper seems to be exactly what i need

unfortunately it is not finished just yet :'(

given that bushing from hackmii team is behind, i'd bet it should end up with interesting results

btw it looks like it certainly wasn't a simple weekend project

5  Topics / Device Hacking / Re: Copying an RFID tag on: October 13, 2011, 04:00:11 pm
i believe trying to forge fake rfid tags is a very valid purpose.

if you break your own system, then you know where it is vulnerable. if you don't attack it yourself, some other person will do eventually. you want that person to be you.

easy or hard heavily depends on the tags type (for MIFARE AES, forget it)

however if it's not your own system, then it's not very legitimate indeed. just don't loose your tags is by far the easiest option smiley
6  Topics / Device Hacking / Re: anyone knows a decent affordable logical analyzer ? on: October 13, 2011, 03:51:03 pm
ok. i'll try to grab my hands on such oscillospes then (rumour is : "everyone wants one", so you guys are probably right anyway smiley-wink)

here is some info i found in the documentation regarding the usb device

USB Low Layer Protocol
The integrated USB driver of the xxxxxxxxxxx device emulates a RS232 serial port.
The xxxxxxxxxxx device is processed as a Communication Device Class (CDC), in accordance with the "USB Device Class Specifications, version 2.0" available from the web site, in "developers, document" section.
The xxxxxxxxxxx device use the full speed transfer rate 12 Mbits/s, and is compatible with USB 1.1 and USB 2.0 Host Systems or hubs.

thanks madworm for the rule of thumb, it makes the picture much clearer now.

so if the transfer is 12Mbits/s i need about 120 "capture per second"
assuming this is the Msps unit mentioned there

then i need the USBee RX as it's the only one offering 100 Msps sampling rate. that's a 1945 USD

however, it seems the Beagle 12 made by totalphase would do the job for 475 USD

i have also seen the
You can get a Saleae Logic clone for $50, I'm talking about the Mini Logic on iTead Studio
on the other post
is it this ? ==>
sorry if i sound stupid, but this is some sort of a "3 in 1" cheap chinese copy, right ? (no offense to chinese ppl)
and it seems the highest sample rate is 24 msps which not enough, so buying this would just be a waste of money

so the Beagle 12 is the best option here then, right ? anyone ever tried it ?
7  Using Arduino / Project Guidance / Re: best way to produce/adapt a casing for an arduino project on: October 13, 2011, 03:21:40 pm
thanks for the feedback

skyjumper, that's a pretty decent summary. my goal for now is to dress my hobby project. but i do not exclude to actually sell some small series of them after all. it could be fun. i think if a quality device really provides a genuine help and does not make any marketing effort, people notice that and are willing to pay. unfortunately none of my project match this criteria for now, but maybe in the future smiley

8  Topics / Device Hacking / Re: anyone knows a decent affordable logical analyzer ? on: October 12, 2011, 03:38:48 pm
That's the Saleae Logic, I've got one and they are great, no analog though.
Correct, but the original question was for a logic analyzer to monitor USB data exchanges so the Saleae logic would be his cheapest option.

as long as it gets the job done quickly without days of scratching my head not understanding what is going on
==> i guess that's enough.

once i'm used to logic analysis then i will know what i need / want / dont want ==> then i may target something more professional.

for now "cheap that works" is exactly what i am looking for.

so will Saleae be able to understand/capture/decode raw usb frames ? (it is digital signal indeed, sorry if i wasn't clear on that)

Important: i have never read the hundreds pages long of official low level USB norm/protocol definition (what i will call here the "transport protocol"). However i am expert with the targeted peripheral "application-level protocol" i want to see on the device under test while it is operating.

9  Topics / Device Hacking / Re: anyone knows a decent affordable logical analyzer ? on: October 12, 2011, 03:36:13 pm
wow... spending 500 USD sounds a bit extreme given the context.
That is nothing for a quality instrument, it won't even get you a decent scope. I spent £10,000 on a logic analiser (at work) when I lived in a house that cost me £8,000.

at work -- it used to be a factory assembling & repairing electronic devices -- they have a complete room full of dozens of unused supposedly expensive HP oscilloscopes somewhere in the back of a warehouse. They have not been used for years. kinda forgotten there. I asked if i could be donated one to have fun at home but i have been told that even though they are not used now, they are too expensive to be donated to employees. i have not been given a price, but it seems they were paid about several thousands EUR

i have used oscilloscopes back at school, it was kind of fun, but well... playing video games was fun too back then smiley
so i have not used any since high-school and embedded hardware is a recent hobby of mine. basically i am not sure i could do anything with an oscilloscope, and an expensive one feels like it might not be a good option of a n00b like me. not to mention that i doubt the oscilloscope would convert the UP/DOWN signals into usable bytes like wireshark does with network.

i have the feeling they will be sent to the trash in the next few months
Should i take one in the trash for a future use then ?
10  Using Arduino / Project Guidance / Re: best way to produce/adapt a casing for an arduino project on: October 12, 2011, 08:18:18 am
the 5K usd price came from a so-called low-cost commercial 3D printer

i wasn't aware of the RepRap, i just love the self-replicating concept. however, i will have to find someone close to my hometown in france who already has one to print my required parts first. and it also looks like even though the price might not be in thousands, at first glance it seems i'd be in for hundred $ and days/weeks of hard work. i'm not sure my spouse would let that happen :'(
i guess i should leave a message in the french forums for that

i like the "sheet-metal bending brake" idea. it never came to my mind that such an approach was indeed feasible for a hobbyist. would you have some good resource to get started for that ?

i still have to get my hands on reallyusefull boxes because they seem to have so much articles that it's hard to go forward. i'll dig into this as well

the ponoko site looks great. however i still have to draw the model first. their price range is about 2 USD/min for a 2D lasercut and about 0.80 USD / cm3 of printed material. the site does not say if 0.80 cm3 accounts for air too (total volume) of just material actually printed (plastic volume). supposedly you can upload the sketch file to get a quote. @justjed : have you tried their services ? what was your experience with them then ?

also for the googler ending here, might be of interest as well. i'll have a look at the nearest hardware store today i think smiley-wink

anyone has another idea maybe ?

11  Topics / Device Hacking / where can i buy these female connectors ? on: October 12, 2011, 07:55:14 am
following my post about connectors smiley,73169.0.html

in fact it turns out this reference can be found on several providers, BUT it is the male connector only. not the **female** connector. According to manufacturer JSR datasheet, the female connector is BM08B-SURS-TF

and that precise female connector ==> i could not find it anywhere (RS, farnell, digikey)

the only provider google finds is a chinese factory on that offers to produce them but you have to order about 5000 units minimum :'(
at about 0.05 USD per unit, that makes a stupid 250 USD without shipping...
it is a bit silly to throw out the windows 250 bucks
not to mention the not-very-green-friendly attitude of this approach

anyone knows a decent provider that would let me order such connectors in small quantities over to europe ?
i dunno maybe i overlooked something

can't wait to get this to work with my arduino board

12  Topics / Device Hacking / Re: exposing the internal core metal of a protected tiny wire without damaging it ? on: October 12, 2011, 07:43:46 am
great !
i tried with very small needle but i couldn't get the needle to "drill" (get through) the wire. i'm affraid of cutting it. prior to use a razor / scapel, i might try the heat with a soldering iron

would you guess the temperature i should use to melt the plastic without cutting the core metal ?

also, i was thinking of something else

last year i had some trooble with internet at home. it turns out to be a problem with some connectors on the wire right outside my home

instead of fixing the broken connectors, the guy used some scotchlock little connectors

something like

however, he had to cut the wires first smiley-sad

i was thinking maybe Scotch produces a similar scotch lock mecanism that
1) prevents from actually cutting the wire you want to connect to
2) applies to very small electronic wires (not electric or telecom wires)

maybe something like

(check out the one with the yellow wires, it'd be exactly the thing ==> plugging a parasite wire to an existing wire without cutting the existing wire)

has anyone tried something like that ?

13  Using Arduino / Project Guidance / best way to produce/adapt a casing for an arduino project on: October 08, 2011, 02:15:16 am

i'm thinking of putting a nice casing for one of my arduino projects. i'd like it to
 * resist to outdoor conditions (mostly humidity and light, possibly frost)
 * if possible to be somehow good looking

i do not have a lot of units to produce and i'd like to try several designs.
i've heard of 3D printers. i've seen this incredibly supercheap model : 5000 USD (omg!)
i've read Print in Plastic
but despite being a very attractive project, the machine they offer you to build feels way of out reach given my experience/tools/motivation

i'm willing to design the thing in a 3D software suite. i remember the nice days with 3d studio max, switching to an industrial 3D software wouldn't hurt that much i guess. i've even used autocad to design the 2D internal layout of various offices in previous jobs. it was fun.

when i see the huge amount of crap stuff in plastic china floods the world with, i a pretty sure they must have a way to produce any kind of casing in a quick and affordable way, but maybe not very environmentally friendly.

do you guys have any idea on how to nicely "dress" my arduino prototypes/projects in a quick and affordable way ?

14  Topics / Device Hacking / anyone knows a decent affordable logical analyzer ? on: October 07, 2011, 02:44:10 pm
following my post about the  08SUR-32S connectors, my ultimate goal is to monitor data exchanges

i beleive the info is likely to be usb data, i know it's pretty much master/slave approach

i think i'm likely to need what's often refered to as a "logic analyzer" (not sure though)

once i'd get the analog measures, i'll need to convert that into something usable

to acquire the data i was thinking of using maybe lxardoscope
but what will perform the sinusoide conversion into hexadecimal numeric data then ?

i've also though of the usbee combinaison
it looks like the cheapest option would be
USBee SX (hardware) ==> 169 USD
USBee Suite Pro (software, works on windows) ==> 299 USD

wow... even though both hardware/software may be good, honestly spending 500 USD sounds a bit extreme given the context. not to mention that i'm not  even sure i'll be capable of using it anyway smiley-sad

i've also heard of the bus pirate thing
=> its 30 USD price tag sounds much more reasonable for educational purposes but still i'll have the analog data -> numeric data conversion to be performed somehow and i dont know how...?

anyone would help me point in the right direction ? i'm feeling kinda lost here :-|

15  Topics / Device Hacking / Re: do you recognize these connectors ? on: October 07, 2011, 02:11:55 pm
thank you all for the tips

i managed to find the reference of the connectors

drumroll plz....


it is a  08SUR-32S  from manufacturer JSR

amazing what google can index sometimes :-)
Pages: [1] 2