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1  Using Arduino / Microcontrollers / Re: startup / boot speed of a Pro Mini 5V on: August 04, 2014, 01:53:52 pm
That's a good idea with the LED13.   I had wondered how I was going to test it...

I need to have at least 50ms left after the program boots I think...   Unless I put a big ass CAP on the circuit and have it charge off the 100ms pulse.   There is current available to support a rapid charge from that pulse.  Or perhaps I will have to actually run a power supply for this thing.

I am not familiar enough with the electronics of the board for changing the fuse settings are you guys mentioned - is there some resources I can read up on to investigate this option?   The code is quite simple, so only a few commands needs to be processed.  If I can get the unit to power on within 40ms then I should be golden....
2  Using Arduino / Microcontrollers / startup / boot speed of a Pro Mini 5V on: August 01, 2014, 09:56:01 pm
Hey Guys,
   So I've tried googling about to see if I can get this info or not, but I'm mostly just coming up with pages that refer to the 16Mhz clock speed of the unit.   I have a batch of Chinese Pro Mini 5V units and I have an idea for a project where I'd like it to interface with another system.  That system sends out a 100ms 18V pulse when commanded to do so - I'd like to know how long the pro mini takes to boot up, as I'd like to attempt to power it up with that 100ms pulse, have it asses a batch of pins and possibly trigger an output for 50ms or so, then I don't care if it powers down again....
   Thoughts?   I'm not sure how to go about testing it myself either as I don't have a scope to record/check with.

Thanks for any help/input!
3  Topics / Home Automation and Networked Objects / Re: w5100 reset idea on: February 24, 2014, 04:14:54 pm
Sorry for the delay (in case anyone was following my plight).

I got sidetracked with other projects and once you install something in a closet behind some stuff, its just a pain to make yourself go uninstall it.. even if I used terminal strips to speed up the connections..

Anyway - I clipped the wire that connected the w5100 board's reset and the arduino, and instead connected it to digital pin 7 on the Pro Mini.  Added the code below at the top of my setup() function and now it seems to be working like a champ on the bench.

  delay(50);             //wait for voltage to stabilize
  pinMode(7, OUTPUT);   //pin connected to w5100 shield's reset
  digitalWrite(7, LOW);  //pull line low for 100ms to reset ethernet shield
  digitalWrite(7, HIGH);  //set line high and now ignore pin the rest of the time

Thanks for the help and guidance guys!
4  Topics / Home Automation and Networked Objects / Re: w5100 reset idea on: February 06, 2014, 08:49:12 pm
I assume that the mini and the shield are now permenantly connected to your pcb; if not though, can you go back & retest them standalone? It rather sounds as though the cause is elsewhere in your system.

Yes, sorta... the ProMini is soldered to a pcb, but the shield is flipped upside down and connected via jumpers inside the abs case.   So I can sort of seperate the two if I needed to.

Do you guys think the htpc psu is not getting up to voltage quick enough and that's my problem?  Would it be better for me to use a 7805 off the 12V rail and create my own 5V rail to work with? 

I'll try the digital I/O line reset trick tonight and see if I can get it to work, but I'd still like to explore the problem and understand it better.
5  Topics / Home Automation and Networked Objects / Re: w5100 reset idea on: February 06, 2014, 01:09:30 am
Thanks for the reply, but that was one of the sites i'd found when googling.
Some more searching led me to discover that solution may not work for every board, and since i'd like to make this a repeatable project, i'd like a sure-fire way to make it work.

The race, I hope, would be solved by powering up the arduino and e-net shield, then waiting 250ms and resetting the shield by pulling an output low...  Just looking for input on whether that's a decent idea or if there's a reason I shouldn't do that.
6  Topics / Home Automation and Networked Objects / w5100 reset idea on: February 05, 2014, 11:49:15 pm
So I'm running a home theater pc that handles all my entertainment needs/media for my TV.  I am part way through integrating some RGB LED lighting controls in this system, and I have the system sending commands to my ProMini328 which i've got connected to a w5100 shield. 

In the breadboarding phase I thought I solved my "requires reset press" problem by using a better power supply and adding a 250ms delay in the code before initializing the shield.  It tested fantastic, with many boots, never failing to initialize properly.

Now I've built the thing onto a pcb, along with some FETs and control circuity (all powered from the htpc's internal 450W psu), but the ethernet keeps failing to start unless i go press the reset button.  Now, before I get the "google is your friend" hate, I have been googling and looking at spec sheets for a couple of hours, trying to find a solution.  I found the resistor/capacitor trick, but some people are reporting that doesn't work...

I'm wondering if I can tie a digital output line from the Arduino (say pin 6) to the reset line of the shield, and force the output low for 50ms in my setup() function, to force reboot the shield.  then initialize it.

I can't find anything about anyone trying this method, so that has me thinking it won't work, but thought I'd ask.   The thing is installed in a closet in another room now and its a pain in the butt to go open the case and hit reset every time.
7  Using Arduino / Networking, Protocols, and Devices / Re: W5100 + ProMini328p Not letting me output PWM on: February 03, 2014, 07:14:53 pm
After much poking about it appears it might be a power supply problem.

I was powering my ProMini from the FTDI adapter, and while it works for simple LED circtuits, once the W5100 is added to the mix, it appears to pull the power down.  I'm using a better 5V supply and now its working properly.

So hopefully someone googling in the future will find this and it'll help them out, I couldn't find much.


Also going to add that it appears to have solved some stability problems I was experiencing with the ethernet shield as well (Wasn't booting/initializing reliably)
8  Using Arduino / Networking, Protocols, and Devices / W5100 + ProMini328p Not letting me output PWM on: February 03, 2014, 05:47:55 pm
I am attempting to create a 3 channel RGB LED Controller that is ethernet enabled.  I have the W5100 shield, and I have used it a bunch with my mega, with less problems, but Now I'm trying to use it with a Pro Mini 328.  I can get the example to load up and feed me the analog values to a webpage, so that's working.

The problem I'm having now, is that I want to send 3 channel values (0-255) from the webpage to the PWM pins on the mini.  I can use any pins (other than 10-13 which is used by the shield) to accomplish this, but in my initial testing, I can't seem to get an actual PWM signal to any of the pins.  the specs show pins 3, 5, 6, 9 should all work for me....

I have tested PWM function with a simple LED/Resistor and a basic sketch, and the pins function.  But as soon as I try to inject PWM in the ethernet ISP example sketch (containing the Ethernet.h & SPI.h libraries), the function disappears.  I'm just using a straight "analogWrite(9, 128);" command to try and find a pin that will work, with no success. the LED doesn't show any sign of life.

Help?  Is there something in the libraries that I can change or is there a hardware problem with timers that I'm not aware of?

9  Using Arduino / General Electronics / Re: 24v Input with critical mA limits on: February 03, 2013, 12:06:34 pm
dc42 - Thank you!  I will look into that chip you suggested.  I have been messing about with a mega board I have, trying resistor networks, and such, but I was looking for something clean.  I wasn't sure what the pin protection diode's ratings were for, or if I could get away with a current that small.   I'm learning quite a lot, and I'd like to learn more about how the clamping diode functions.  Any links/sites you can recommend that will explain the function and schematic layout of such a feature?

MarkT - I have been trying dividers, but was scared of burning out my mega's chip with too much current, and then I also had concerns since the signal back from the device will be over a fair range (20-27 volts) so I didn't want to be outside the safe input voltage ranges in the arduino at any time.

Thanks guys!  Any other suggestions, feel free to keep them coming!
10  Using Arduino / General Electronics / Re: 24v Input with critical mA limits on: February 03, 2013, 01:58:56 am
I also just came up with problem number 2...  the TI CD4051 multi chip i am mucking about with doesn't appear to like 24V signals...  At least not what I can understand from the datasheets...
Anyone know of another good option?  I don't mind running the chip's Vdd from the seperate 12v source, but it has to be able to switch signals up to 27volts, so lets say 30 to be safe.
11  Using Arduino / General Electronics / 24v Input with critical mA limits on: February 03, 2013, 01:16:44 am
I am building a circuit that is basically testing for continuity across a very low ohm circuit.  I'm using a multiplex chip to sample multiple lines for a split second and then rotate to the next one, it will update a remote arduino that will then display the status via LEDs lighting or not.  I can not draw more than 10mA from the circuit without consequences.  I'd be happiest with 5mA.

the 24VDC source will be batteries, and I will run a 7812 (or equivelant) to power the mega as well as a couple other small devices in the enclosure.  Total resistance in the device circuit (not counting anything added for this continuity test) will be in the 2-12ohm range.

The "continuity circuit" is operating on 20-26v (batteries under varying condition), but the arduino (5v MEGA) needs a 3-5V input.    My first thought was to use a 5V regulator chip to punch it down to 5v exactly, but I don't think I can get one that will safely stay within my 10mA limit total draw can I?   Next I considered an optoisolator, but i'm not sure if that works either - the ones I looked at (4n25 i think?) looked like the draw was higher, but I'm not 100% sure I understand exactly how they work.

I'd also strongly like to minimize the chances of a failing chip causing the draw to go over the 10mA mark, so things that reduce the risk of shorting to gnd make me happiest.

Sorry about the really bad mspaint jpeg, but thought it might help illustrate what i'm trying to do.
Thanks in advance for the help!
12  Using Arduino / Programming Questions / Re: TimeLord Library on: October 30, 2012, 01:21:34 am
Apologies - I did read the first half of that post and thought the rest was getting too far down the process to apply to me.

Bad newb.   smiley-red

the error I don't think I can copy & paste - its friggin huge.
But as always, as soon as I posted a question I think I figured part of it out.  I was just frustrated after 30 minutes of messing about that I hadn't gotten anywhere.  I moved where i was putting the code outside of the setup/loop functions and it started working better for me.

I did restart the IDE after installing the library.
I'm not 100% sure what the errors where, I started a fresh sketch to attempt to understand how to use the library and now I'm making a bit of progress.

I'll be happy to plug away at it a bit more now and I'll post back when I hit the next wall.  Thanks for the super fast reply!
13  Using Arduino / Programming Questions / TimeLord Library on: October 30, 2012, 12:47:09 am
I'm trying to make a lighting controller that will fade lights in and out to simulate daytime.
I googled and came up with the TimeLord library, which seems popular for people doing this task.

Problem is, I can not figure out how to get the library to work in my program. 
I have tried using the <include> statement, as well as copy & paste the code from the .cpp file into my sketch.

I don't get any warnings when i try to compile, but the compiler spits back errors saying there is multiple declarations of various things from the library's code.

I'm pretty new to all this and tried googling to get answers, but I can't figure it out. 
Can someone tell me what i'm doing wrong? or maybe give me a snippet of code to pull something like a sunrise time?

Thanks in advance for the help.

If it matters, I'm using an ArduinoMega2650 and the 1.0.1 IDE
14  Using Arduino / LEDs and Multiplexing / Re: High Power LED Dimming Q's on: March 05, 2012, 04:16:06 pm
Got it working - thanks.

Looking at it, I'd like to make some changes like add a 5V regulator (ie 7805) onto the board.  I'm thinking a passive mod, just add the 3 pad holes so I can solder it in on the first board, and then jumper 3 or 4 boards together to control all the channels.. Just gotta figure out how to use Eagle now...

I was poking around onSemi and figured out they have sample units for shipping, so I'm going to order a  10pc sample set of the CAT4101 chip (~$15) so I can try them out. 
I like the idea of a constant current driver being in charge instead of just a transistor.  Overall, I think i'm going to have to put out about the same money either way, so might as well do it right.

Thanks for the help so far guys - I'll post up details/updates/etc as i work through it all in case it helps someone else in the future.
15  Using Arduino / LEDs and Multiplexing / Re: High Power LED Dimming Q's on: March 03, 2012, 12:26:48 am
Poking around I noticed that there's already an Eagle schematic for this:
For $10 at iTead or Seeedstudio you could have 10 of these boards made up. There's only 12 components per board and you could even convert those resistors and capacitors to through-hole if you wanted to.

I can't open that file - i installed a copy of Eagle and it says its not a valid file?  I also registered with onsemi to look at ordering the chips, but they're out of stock...  boo...
Anyway - am I doing something wrong with Eagle?  will the freeware version work for it?
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