the Open Source hardware thread

[Shah]

From where can I get Tower Pro MG-995 and HXT900 servos online? I need a few of them. I am getting MG-995 for around 1.5k INR. Is it a good price? I can't find the HXT900 anywhere (not even on eBay)

 

[icebags]

^
search *shop.sumeetinstruments.com/index.php?route=product/product&path=49_87&product_id=965
then search *www.thinkdigit.com/forum/open-source/176760-open-source-hardware-thread-4.html#post2021158
then @ ebay.in, ask about it to "onlinetps" seller, if they can arrange it, then ask them to list it.
if still not found then idk.

 

[icebags]

found some cool stuff :

 

[icebags]

any idea why float to string is not taking place properly ?

i used "sprintf(f2str,"%.2f",l_value);" to put value (float) to f2str (char[30]) and when i am printing f2str, i am only getting "?".

 

[Shah]

any idea why float to string is not taking place properly ?

i used "sprintf(f2str,"%.2f",l_value);" to put value (float) to f2str (char[30]) and when i am printing f2str, i am only getting "?".

have you included the header file "math.h"? AFAIK, sprintf returns a negative if the conversion fails. I might be wrong, though.

 

[icebags]

but l_value is just the name of floating variable, why does the name matter ?
and i don't think sprintf needs math, it already compiled successfully.

 

[gopi_vbboy]

any idea why float to string is not taking place properly ?

i used "sprintf(f2str,"%.2f",l_value);" to put value (float) to f2str (char[30]) and when i am printing f2str, i am only getting "?".

1.Have you checked compiler documentation for sprintf you are compiling on?Does it support those formats?
2.What is value of float?garbage?

 

[icebags]

thanks for the suggestions, it seems a compiler issue, cause, the same works in gcc.

anyways, i handled this case by storing before decimal and after decimal points in two different integers.

 

[Shah]

I recently got a ITead BT Shield v2.2 and I have been experimenting with it. I have programmed it and developed an App for my WP to connect with it. Now, I can successfully connect with the shield but, I can't send any data to the shield from my WP. Further inspection revealed that BTSoftwareSerial.available() function is always false. How can I fix it?

 

[sankar]

I recently ordered some components from ebay.com.inventory includes a Bluetooth shield for Arduino and two atmega a16.
can anyone share some experience with ebay.com and international standard shipping.
and how this ebay grantee works in case of international standard shipping will they refund my money if i dont get the item as they say ?
the seller is asking me to pay a small amount to send the items through a registered post.the seller is based in china.
guys i need a little advice on this.

 

[icebags]

tried basic oscilloscoping with nokia 5110 lcd shield:
*i.imgur.com/1kYfy0P.jpg

got excited, & bought 2.4" high resoltion tft colour touch display off ebay, finding driver was difficult though, but found something ultimately what works. will try to tweak the driver a bit for suiting my needs better:
*i.ebayimg.com/00/s/MTAwMFgxMDAw/z/bMoAAOxy0NtTDxfI/$_12.JPG

also bought a pair of NRF24L01 2.4GHz wireless transceiver modules to try out wireless data comms:
*i.ebayimg.com/00/s/MjI3WDQ3Mg==/z/jDAAAOSwcnpTnHJ1/$_12.JPG

Spoiler

previously bought: nokia 3110 replacement screen, but didn't know connecting it will be beyond my capabilities. rs.150 wasted.
*i.ebayimg.com/00/s/NzUwWDEwMDA=/z/7MoAAOSws65TpEpe/$_12.JPG

 

[Nerevarine]

what exactly will u be building.. a lcd fan controller for your cabinet ?

 

[icebags]

nope, a plain & simple oscilloscope was the goal, but arduino itself is not any good for waves >2KHz or ~8KHz with ADC register tweaks. i still want to build one, but need one high speed dedicated ADC chip to see waves of 50kHz range, that i wanted.

other than that, i am thinking of putting the b/w lcd onto a 5w solar panel that i have, to monitor power output and see the daylong power curve. just some hobby stuff, nothing special.

 

[Shah]

tried basic oscilloscoping with nokia 5110 lcd shield:
*i.imgur.com/1kYfy0P.jpg

got excited, & bought 2.4" high resoltion tft colour touch display off ebay, finding driver was difficult though, but found something ultimately what works. will try to tweak the driver a bit for suiting my needs better:
*i.ebayimg.com/00/s/MTAwMFgxMDAw/z/bMoAAOxy0NtTDxfI/$_12.JPG

also bought a pair of NRF24L01 2.4GHz wireless transceiver modules to try out wireless data comms:
*i.ebayimg.com/00/s/MjI3WDQ3Mg==/z/jDAAAOSwcnpTnHJ1/$_12.JPG

Spoiler

previously bought: nokia 3110 replacement screen, but didn't know connecting it will be beyond my capabilities. rs.150 wasted.
*i.ebayimg.com/00/s/NzUwWDEwMDA=/z/7MoAAOSws65TpEpe/$_12.JPG

Cool. Nice to see a post on this thread after a long time. And, keep this thread alive.

 

[krishnandu.sarkar]

Awesome.

 

[icebags]

Cool. Nice to see a post on this thread after a long time. And, keep this thread alive.

yah, kinda lonely. u ppl should do some stuff too.

 

[RCuber]

been lurking around the interwebs to find my next board to kill some time (one month) very interested in Beaglebone Black after watching the video below.
[YOUTUBE]XAeeDIkQ0Kw[/YOUTUBE]

I'm thinking of buying a board instead of a Android TV stick, but I don't think these are that powerful for media center.

 

[sankar]

hello guys
does anyone have any experience with the 28BYJ-48 stepper motor ?
i cant find a gear to fit into the motor i mean in the outer arm.
[MENTION=44484]icebags[/MENTION] what kind of MCU did you use with the nokia 5110?

 

[icebags]

atmega 328 or 8, as usual. library is available at adafruit.

 

[Shah]

Lately, I have been thinking about developing a Rubik's Cube Solver robot using an Arduino. I have decided to design that in a way where the Arduino scans the colours of the Rubik's cube and sends it to a PC or a Phone to generate an optimal solution. Then, the Arduino MCU will execute the solution generated by PC and execute it using servo arms.

So far, I'm sure about all the things except the Colour scanning. I want some help with it as I haven't used any colour sensor at all. Can you guys tell me what Colour sensor should I prefer?