the Open Source hardware thread

[quagmire]

^ Shah, I recommend you use a phone/webcam as a primary camera to completely scan the cube. An image processing algorithm running on (say OpenCV) phone/laptop will accurately give the colors and the individual turns that you have to make. You can then actuate the result using Arduino.
It is possible to interface a camera with Arduino (check Omnivision cameras) but it is not possible to achieve a decent frame rate or resolution that you require, plus those cameras are expensive and not available in India. Webcams as cheap as 6$ are available online..

Else you could ditch the Arduino and graduate to a Raspberry Pi or BeagleBone which is a complete solution not requiring a PC at all.

 

[Shah]

^ Shah, I recommend you use a phone/webcam as a primary camera to completely scan the cube. An image processing algorithm running on (say OpenCV) phone/laptop will accurately give the colors and the individual turns that you have to make. You can then actuate the result using Arduino.
It is possible to interface a camera with Arduino (check Omnivision cameras) but it is not possible to achieve a decent frame rate or resolution that you require, plus those cameras are expensive and not available in India. Webcams as cheap as 6$ are available online..

Else you could ditch the Arduino and graduate to a Raspberry Pi or BeagleBone which is a complete solution not requiring a PC at all.

Thanks for the reply. I'll use my Phone's camera then. (I don't have a webcam, Time to get one.)

The thing is even RaspPi can't find the optimal solution in a short time. So, To find an optimal solution in a short time, I have to use a PC.

 

[vedula.k95]

Hello [MENTION=129731]Shah[/MENTION],finally i am home and made a purchase of arduino
as you said me,i think i have ordered a clone one for around Rs 780
UNO R3 Development Board FOR Arduino Compatible USB Cable NEW | eBay
is the purchase enough for me to understand all the basics?
and you said a 9 volt battery with a resistor and i will never break the board?

 

[Shah]

Hello [MENTION=129731]Shah[/MENTION],finally i am home and made a purchase of arduino
as you said me,i think i have ordered a clone one for around Rs 780
UNO R3 Development Board FOR Arduino Compatible USB Cable NEW | eBay
is the purchase enough for me to understand all the basics?
and you said a 9 volt battery with a resistor and i will never break the board?

That will do.

BTW, I told about a 9V battery with a IC7805 (Voltage Regulator) to power it. You will need some capacitors to make a voltage regulation circuit.

- - - Updated - - -
[MENTION=273316]vedula.k95[/MENTION] Here is a pic of a Voltage Regulation circuit that I tried soldering on a PCB.

*www.digit.in/forum/attachment.php?attachmentid=15046&d=1418271767

The capacitors I have used are 10 uF and 100 uF (by u I mean micro)

- - - Updated - - -

Get yourself a breadboard, multimeter and a few capacitors, resistors and transistors. Also LEDs. They will be very much useful for you.

 

[icebags]

Hello [MENTION=129731]Shah[/MENTION],finally i am home and made a purchase of arduino
as you said me,i think i have ordered a clone one for around Rs 780
UNO R3 Development Board FOR Arduino Compatible USB Cable NEW | eBay
is the purchase enough for me to understand all the basics?
and you said a 9 volt battery with a resistor and i will never break the board?

u may just power it through usb cable. battery + converter can be used for standalone app.

meanwhile my latest arduio diy :
*i.imgur.com/0gMEt4t.jpg?1

pls purdon the bad q pic and the piece of supporting paper !

 

[Shah]

meanwhile my latest arduio diy :
*i.imgur.com/0gMEt4t.jpg?1

pls purdon the bad q pic and the piece of supporting paper !

Great work, [MENTION=44484]icebags[/MENTION]. What microprocessor is it? Also, what are the list of components you used?

 

[icebags]

^nothing much, just one atmega8, with op-amp (LM324) buffer interfaced at it's 4 analog inputs. 1 button is also there u see at right side corner, for menu navigation on 16x2 display.

i actually thought u would ask whats its purpose ......

 

[sankar]

^nothing much, just one atmega8, with op-amp (LM324) buffer interfaced at it's 4 analog inputs. 1 button is also there u see at right side corner, for menu navigation on 16x2 display.

i actually thought u would ask whats its purpose ......

whats its purpose ??
connecting the lcd to the micro is a pain

 

[icebags]

whats its purpose ??
connecting the lcd to the micro is a pain

connecting 16x2 or nokia ones with pcb connectors is not pain ...... just try it.

here, can u guess the purpose now ?

 

[Shah]

connecting 16x2 or nokia ones with pcb connectors is not pain ...... just try it.

here, can u guess the purpose now ?

I am too to get the purpose even after watching the video thrice.

BTW, Was it to build a DIY Arduino from sctrach?

 

[icebags]

hmmm i think it's because i just pressed button twice in the last and it skipped the first monitor menu, and u could not see the multiplied port reading menu.

well, its not exactly development board, but can better be referred as application board. if u see 1:15, in the display there r 4 analogue readings from 4 buffered analog ports (via those black screw terminals) and the second mode is simple temperature monitor from analog port 0.

this is why in the first display the 0th reading is low, that's the temperature sensor voltage o/p.

anyways, for the 4 reading display, the button can be used to properly set the reading of each analog port, by setting multiplier option. as u can see i am setting them from 1:43.

this is because in this board i used lm385 voltage reference diode for 1:235V, its much better than the arduino internal voltage reference.

so, lets say i want to measure a 5-7 V source, then i will be using a 1:10 voltage divider resistor network, to get the o/p in the range of 0-1.235V. so, to display actual voltage on screen i will need to set multiplier for that port , which would be x11 if i use a 100k & 10k resistor for voltage divider.

now ask me why i go through all the trouble to display 4 analog port readings on the display at once, whats the purpose ?

 

[Shah]

hmmm i think it's because i just pressed button twice in the last and it skipped the first monitor menu, and u could not see the multiplied port reading menu.

well, its not exactly development board, but can better be referred as application board. if u see 1:15, in the display there r 4 analogue readings from 4 buffered analog ports (via those black screw terminals) and the second mode is simple temperature monitor from analog port 0.

this is why in the first display the 0th reading is low, that's the temperature sensor voltage o/p.

anyways, for the 4 reading display, the button can be used to properly set the reading of each analog port, by setting multiplier option. as u can see i am setting them from 1:43.

this is because in this board i used lm385 voltage reference diode for 1:235V, its much better than the arduino internal voltage reference.

so, lets say i want to measure a 5-7 V source, then i will be using a 1:10 voltage divider resistor network, to get the o/p in the range of 0-1.235V. so, to display actual voltage on screen i will need to set multiplier for that port , which would be x11 if i use a 100k & 10k resistor for voltage divider.

now ask me why i go through all the trouble to display 4 analog port readings on the display at once, whats the purpose ?

Enough of suspense, Break the ice, [MENTION=44484]icebags[/MENTION]

 

[icebags]

Enough of suspense, Break the ice, [MENTION=44484]icebags[/MENTION]

there is not much suspense actually, just because multimeters show only 1 reading at once, consider this as 4 in 1. say when building a new ckt, i can monitor the input voltage at one, input current at an another, and there will be 2 more ports for testing / debugging...... just like that. *s.yimg.com/lq/i/mesg/emoticons7/29.gif

 

[sankar]

connecting 16x2 or nokia ones with pcb connectors is not pain ...... just try it.

here, can u guess the purpose now ?

could not figure out the second micro with the 14 pin.
what is it?
BTW how did you latch that switch? did you use the interrupt to trap the switch ?

 

[Nerevarine]

Guys I have an old micromax android phone lying around whose touch is busted but the display works fine.. Is it possible to remove it and use it with say ? a raspberry pi ?
Link to any tutorials on how to get started

 

[icebags]

could not figure out the second micro with the 14 pin.
what is it?
BTW how did you latch that switch? did you use the interrupt to trap the switch ?

>.> thats just lm 324 opamp for buffering the mc analog inputs, duh ! and recently i have found another good use for this display board, no need to ask me what, i will post pics and details soon

and the button is just connected to a digital input pin, no interrupts, just wrote a little subprogram to detect whether its a long press or a short press, when there is change of state in digital pin. but debouncing takes some experimentation before, to be taken cared properly.

Guys I have an old micromax android phone lying around whose touch is busted but the display works fine.. Is it possible to remove it and use it with say ? a raspberry pi ?
Link to any tutorials on how to get started

firstly, a driver program library needs to be written, based on the display chip - by going through the datasheet, which is a time consuming job and requires good understanding of these stuff ! people use some common displays, which have readymade library or details avaible, if mmx lcd is not of them then .....

then, those fone displays have kinda microscopic connectors, and are very difficult to connect by hand, so, unless u have the proper connector, .....

 

[Shah]

So, What's the cheapest UNO compatible Wi-Fi shield that I can get? All Wi-Fi shields I found are well above 4K. I'm looking for something around 1K INR. The cheaper the better.

 

[quagmire]

^Shah, WiFi shields are expensive, go for standard ones only, lots of China fake shields are selling online..
If WiFi is what you want, you can try this
Serial WIFI Transceiver Module ESP8266 [WWI8266ESP] - $3.24 : Elecrow bazaar, Make your making more easy

 

[Shah]

^Shah, WiFi shields are expensive, go for standard ones only, lots of China fake shields are selling online..
If WiFi is what you want, you can try this
Serial WIFI Transceiver Module ESP8266 [WWI8266ESP] - $3.24 : Elecrow bazaar, Make your making more easy

Thanks for the suggestion. Found the same on Amazon (Amazon.in: ESP8266: Electronics)

Looks like I have to get a breakout board along with it.

 

[quagmire]

yup, thanks. i have also purchased a huge lot of 1watt & 0.5 watt leds, will slowly slowly try to put them at different parts of house, just thinking a way to efficiently drive them from 12/6v source !



here you go, pics !

Spoiler

ripple from a wall wart 12v smps, on ~600mA linear load : its noisy, too many frequencies, so, i guess triggering was a bit difficult with this substandard 10MHz scope. The main is 100KHz, but if looked closely, the rising edge has very low duration high freq MHz level ripples, with amplitude in 10s of volts.
*i.imgur.com/QC6lMcg.png

clean signal, from the 1KHz calibration port is very clear though
*i.imgur.com/wGG9P1E.png

its the most basic as it gets, 10MHz analog, good for basic studies of modulation, basic power supply design and valuation, audio amplifier design, testing & debugging and for probing into not so high frequency stuff. i want to get a DSO of 100-200MHz in future, but before that wanted a CRO for cheaper price.
it was 8k at urjakart, the HTC model. after i bought they not only reduced the price, but also included cheaper MetroQ model - same stuff from same/different chinese factory perhaps, but different indian brand names. geez, i could have saved ~1.5k with metroq model.
this is substandard to the standard 20-30MHz stuff people use at colleges, but it's okay with me for now.
i m also aware of the usb ones, but people suggested to get dedicated ones, they even warned me to get at least 20MHz models, but i didn't listen.



nice, congos, happy holling.

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?