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1  Using Arduino / Project Guidance / Re: 4 Digit, 7 Segment Counter Help on: July 20, 2014, 08:31:48 pm
I to would suggest that same chips CrossRoads suggest (MAX72xx chips)

Where my advice differs is that being that you are new, you may want to look into using one the available libraries to get your project up and running..

I use the LedControl library alot myself for quick and easy set-up

That being said the advice & approach given above will make you a better coder and understand the SPI protocol so it can be applied to other projects/SPI devices..    It is a 'crutch-free' approach and ultimately gives you more control instead of being pigeon holed into only being able to use the pre-made functions of a library.

2  Using Arduino / Project Guidance / Re: Controlling Arduino using iPhone on: July 20, 2014, 07:51:00 pm
Thanks!  I did -not- know about this limitation with iPhones!!

(how sad).. I really like the HC-05 BT modules!  they are only a couple dollars (USD).. and are dead simple to use!

Its a shame those iDevice people cant take advantage of this!
3  Using Arduino / Project Guidance / Re: wifi rgb light remote on: July 20, 2014, 03:02:48 am
umm...good luck?  smiley lol..

seriously.. was there a question in there?

if you dont want to use your iPhones 'data' (not sure what you mean though?)..then I suggest a bluetooth module.

they are dead easy to work with.  You could also develop/write an app for your phone that uses its bluetooth to control the app a bit easier then just a regular bluetooth terminal type well as another arduino device if you want a dedicated 'remote'

Are you planning on using high powered RGB leds? (like an led star?), if so you need to focus on making/implementing a constant current driver for this as well.

4  Using Arduino / General Electronics / Re: Best way to power 3w RGB LED? on: July 17, 2014, 12:02:04 am
that is correct..  as stated this is NOT the current circuit/design...  this is an example of the only type of constant current driver I have done before....  (and also as mentioned it was only designed to use 1 channel/color at a time)..

however I was told that using the LM317 it not the best approach.  if that is not true, and this is fine... then I'll just add 2 more and make so I -can- color mix....  but if it is NOT the best way..  then  I was/am asking what other IC can be used?  or some links to a nice and easy to follow set-up of a constant current driver.  The one posted doesnt seem a as easy or straight forward as using an LM317 though... (uses more components...etc)..

a quick google search shows that many people use this LM317 set-up in a similar fashion though?? 

so to summarize, yes you are correct..  that particular board design & schematic were designed to only have 1 channel on at a time. smiley

5  Using Arduino / General Electronics / Re: Best way to power 3w RGB LED? on: July 16, 2014, 08:53:34 pm
Thanks for the reply guys.


haha..  I'm trying to get 'comfortable' with learning how to make a 'correct' constant current driver.  Why I am askingfor advice/suggestion on an easy to use chip for this purpose. smiley  Something that doesnt have alot of extras/fluff to side-track a beginner like myself to all this..

I have made this pcb in the past (as mentioned) using an LM317 chip:

but if I recall this was an old chip and an old approach (although it worked and what was in the datasheet)

I would just do this 3 times (1 for each channel/die of the led) if not for the recommendation there was a better way. (so I am trying to ask/learn) smiley


sorry, I guess I was thinking (erroneously) that I needed to have a power supply with enough voltage for  all three led channels to be on...

So if I used a 5v wal-wart as my 'source'.....  would that mean running my Arduino without a vRegulator? (since I usually use some sort of vReg to keep a constant 5v feed to my Arduino circuit...  and then a +3.3v regulator fed -from- the +5v power any other this case the BT module)

so just a 'raw' +5v power source (direct from wal-wart for example).. and then all my circuits in parallel from that?


Thanks for the schematic.  I only briefly looked at it.... (and am already
which I'm sure stems from my lack of experience in this area.. smiley

but it uses BOTH a transistor and a moseft?..   

excuse my ignorance on this question, normally how a constant current driver is set-up? (and not through some dedicated IC or something?)

I have not read the link yet.. but will do so in hope I keep learning.  Appreciate it.

@GrumpyMike (again) lol..

Your comment makes me feel like this is not the best way?  I'm also not clear what you mean by 'power' resistor?  Are you referring to resistors that rated for like 1w and over? (would like to know so when I see the term again in use I understand the meaning)

Also (on a side note) what ever happened to that board I shipped out to ya in the UK?  smiley

Thanks everyone.

6  Using Arduino / General Electronics / Best way to power 3w RGB LED? on: July 16, 2014, 12:55:30 am
I'm not asking for any schematic/diagram here...just some general discussion/feedback (suggestions)

I'll make/post my Eagle files for 'review' once done...

I want to whip up a custom pcb that is basically a stripped don 'Arduino' with an on-board RGB led (to stick in some lamp project), and an HC-05 bluetooth module embedded.

anyways..  I started to think that using a high powered RGB LED (star)  might be  better way to go (for maximum brightness)..

the specs for the led are as follows:

    Red: 2.5V ~ 3.0V, 350mA
    Green: 3.2V ~ 3.8V, 350mA
    Blue: 3.2V ~ 3.8V, 350mA

- Star size: 20 x 20 x 1.6mm

- Note: each color channel is able to take a maximum of 350mA of current, thus a 1050mA combined current input and the 3W rating

I have only designed/worked with these RGB led stars in a single channel fashion  (1 regulator, 3 x transistors and only one channel/die active at any time, no color mixing).

This time I want to be able to color mix. (so have more than just one single die active at any given time)

Would I just plan on:

* using a 12v wal-wart to power this thing? Is there a better approach here? I not too keen on trying to use a 12v input source that gets chopped down to 5v (or whatever) by the vRegulators

* would I need to use 3 separate vRegulators? one for each color/channel??  (along with 3 transistors..etc)

In general what would the best approach to tackle this with?  Any other suggestions?

I'm not very clear/comfortable on making a constant current circuit for this type of set-up..

I had used (which I was told later is not the best approach) an LM317 as my base


And the:

I had followed the datasheet and was my first/only constant current anything.

If there is a better way with a different chip that is even easier to set-up (not a bunch of other components needed is a key point for me, along with easy to follow/understand wiring, since I'm just a hobbyist)   smiley

the best battery pack, that has enough voltage/current .....that allows for all components (arduino circuit, bt module and rgb led star) voltage drop....   close enough in the vF of the leds (and the vRegulator needs) so it doesnt burn un-needed heat...etc with a nice, EASY chip for making constant current circuit for the led as well..

thoughts? suggestions? feedback?

Thanks in advance!


7  Using Arduino / Project Guidance / Re: Prop "Secret agent palm scanner" (Capsense, LEDs, and 6v chime) on: June 03, 2014, 09:00:40 pm
I believe he posted pics for the IR stuff? (I didnt check up close though.. was just off top of my head)

digitalRead will give you a 1 or 0..  (ie: on or off)..  and not give you any 'range' of a value like an analogRead will..
8  Using Arduino / Audio / Re: Wave shield plays some wav files but not all, any idea ? on: June 03, 2014, 08:57:37 pm
Do the file names follow the 8.3 naming convention?

have you tried other files (with same name).. or same file with new name?
9  Using Arduino / General Electronics / Re: Reverse mounting tactile switches on: November 17, 2013, 06:57:16 pm
Maybe try the GreaseMonkey plug-in for firefox.. and the Digikey script..??

it really helps put things at your fingertips..with pics..etc..

I have looked at reverse mounted SMD LEDS before... (but never for switches.. so I'll be curious to see what you find/come up with)..

also.. a problem "I" faced (with the reverse LEDS stuff)  was:

1.) how to make the HOLE/window/cut 'legally' with the design rules?  to mount the LED (part)?  usually need to be 'xx' away from any edge.. parts not covering/outside of the PCB outline..etc.

post back on any reverse mount switches you DO find.

10  Using Arduino / Project Guidance / Re: Fall sensor on: November 03, 2013, 10:12:16 am
(and I know this isnt easy.)... I think you need to work on your English a bit.. or at least go back and re-read what you typed, its hard to decipher all the things your saying correctly.

MY suggestion is to do this in STEPS.. (small steps)..

1.) get an Arduino
2.) get your accelerometer/fall sensor of choice
3.) connect them together..
4.) keep your USB cable plugged into the computer
5.) output the accelerometer data to the serial monitor.

once you get that far.. come back.

Also be ready to post a list of the data you require:

(eventually GPS coords?)

and because you want some sort of visual representation in the way of graphics...  I would look into using PROCESSING to take your streamed data and make 'graphics' for it.

however for you.. your first steps of getting Arduino hooked up correctly.. and the accelerometer connected, working and outputting values/data is crucial.

11  Using Arduino / Project Guidance / Re: Fall sensor on: November 02, 2013, 07:21:13 pm
I agree with PaulS..

I wont comment on your approach or the values/data you need...

but start simple (as suggested)...
by using the serial monitor in the Arduino IDE....  if you are getting the values/data you think...

and you 'are' in fact triggers events/functions based on those values...

then you can worry about transmitting the data OUT to other applications..

Im not familiar with GPS or any of the shields...etc.... but..   Im going to assume, that one of the 'triggers' that happens when a 'fall event' has been detected... is to grab the local GPS coords.. and send them out to the C# app?... yes?  (along with whatever other data you want to pass of person who fell?)

the part I'm missing is (maybe read to fast?)...  was HOW are you connecting your/this C# app/platform to......  anything?

the 'fall sensor' product.. will need to be stand alone....yes?  *(around the neck or whatever)*  and have to power it self, have the sensor connected to do constant reads/checks., have a way to pass/communicate this data OUT of the product/project... and ONTO its final destination?  (C# app?)

how is this C# app going to get any sort if data sent to it?
some sort of Wi-Fi? RF? Bluetooth? module?... on BOTH ends?  the C3 end.. and on the Arduino/Fall product end?

explain how you see this working?

12  Using Arduino / Project Guidance / Re: Failed to pass board_qc using UNO with USB Host Shield 2.0 on: November 02, 2013, 07:07:35 pm

at the top.. did you miss this part:

GPIO test. Connect GPIN0 to GPOUT7, GPIN1 to GPOUT6, and so on
Test failed. Value written: 00 Value read: FF
Press any key to continue...
GPIO test passed.

although I'm not clear on what test actually failed.. as the GPIO test seems to 'pass' right after it?

13  Using Arduino / Audio / Re: bit stream / bit bash low quality audio out single pin? on: November 02, 2013, 06:59:06 pm
Maybe look at the SimpleSDAudio library?

uses PWM for audio output.. reads a 'file'  (cant recall the format,.... .asf perhaps?) from the SD card... and plays it back through 1 (PWM) pin.. pin 9 I believe it is...

however that is the barebones... not sure if that will be LOUD enough for you with any sort of amp?

I used it for a very generic/minimal spiderman webshooter pcb/project.. where space was EXTREMELY limited...
worked fine.. but not very loud (although loud enough for that purpose)  smiley

14  Using Arduino / General Electronics / Re: Who can identify Chinese led color names please? on: November 02, 2013, 06:51:04 pm
fungus for the win!  smiley

nice job!
15  Using Arduino / Project Guidance / Re: Project help (MAX7219) related... (connecting/dis-connecting from main project) on: October 21, 2013, 07:27:50 pm
haha.. no worries bud!  smiley

I just figured since you were already sorta familiar with the project....  you might have spotted something quicker  smiley-wink

Thanks for the link!  I'll check it out (all the articles/posts the better)  <-- I just have a fine line between being able to use some of the advice and just 'reading it'  sometimes you need a nice foundation to use some of the advice here.. and sometimes it comes with some nice background for noobs.

When I got some free time.. I'd like to also try and try edit/alter that lib so that the initialization code is wrapped in function and much easier to call/access..

(I'm still abit confused as to why the DEFAULT scan limit of 7 works initially if the chips are connected/chained upon initial power-up...  but when (I guess) initialized by itself.. the second chip 'needed' a scanLimit of 4 for all leds to light up again and work/display correctly...  from what I understand..having a scanLimit of 7 should NOT have hindered anything even if was purposefully

anyways... I'll shoot the latest copy.. (although outside of a few code clean-up edits (elsewhere).. they are very close..

but still I'll send it..  always open to feedback/suggestions (when I can apply/understand them!)  LOL..

I understand/ is better (or would be nicer) to have a lower level access to things, and be writing my own code/libraries instead of being dependent on 'front ends' to do the same things....

Im just not really at that point yet.. (getting closer maybe?)  smiley..

and from what I gathered.. the library was doing sorta the same thing..(pre-defining registers...doing the open/close latch..send data..etc for me/us)........  (just not doing the initialization correctly from what it looks make it easy to re-initialize things)

it helps beginners be able to 'do things'...  but I also understand that learning that basic SPI process IS important.. (and something I admit I dont fully get yet...a little bit.. but when I start seeing things being defined like: brain shuts off a little bit each time!) 

the more time I spend around reading other posts.. and walking through my own projects.. (just submersing myself in this).. things will click and become 'common' knowledge/terminology..etc..


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