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16  Using Arduino / Project Guidance / Re: The easiest/best way to drive a Numitron (IV-9) with an Arduino Uno on: May 10, 2014, 11:50:05 am
Hi Paul,

I've received some TPIC6B595, as far as I can see they seems to work in the same way as the 74HC595 (I'm probably wrong). I've got one Numitron-IV9 plugged in. Everything is working but I've got a voltage issue I think.

The numitron needs between 3.5V and 4.5V. the problem seems to be that when there's more than one filament on it needs more.

I've got a countdown sketch going, and once it's started counting it seems stable, "1" is as bright as "8". So I'm not really sure what's happening as when the arduino reboot, the shiftregister will light a filament at random and that one is very bright as I'm putting 5V in, but once it's running it's pretty dim. (that's just when the arduino is stopped to upload the sketch at a moment when a filament is on)

So I don't really know how to deal with that, seems to need more voltage but I don't want to burn the filament at start. I also want to use more than one Numitron and feel like this could escalade pretty quickly.  Any ideas?

(some source that seems to confirm the voltage change: http://www.instructables.com/id/Numitron-clock-thermometer/step4/The-numitrons/ )
17  Using Arduino / Project Guidance / Re: The easiest/best way to drive a Numitron (IV-9) with an Arduino Uno on: May 04, 2014, 01:35:10 pm
Thanks Paul for taking the time to answer.  I'm going to buy some TPIC6B595s then. I will try to remember to post my results so we finally have an example or thread about how to actually drive those numitron.

18  Using Arduino / Project Guidance / Re: The easiest/best way to drive a Numitron (IV-9) with an Arduino Uno on: April 30, 2014, 04:18:51 pm
Ok I see that they actually recommend 6ma and that 20ma is the absolute max. But is it working for a few people because in the end it's taking less than 5V?

Is that what Grumpy_mike is saying here: http://forum.arduino.cc/index.php/topic,15620.0.html
Quote
With a 220R resistor you will be pulling about 18mA from each pin. That is somewhat overstress things. However, these outputs sag a bit when you start taking current from them so if you measured it you would probably find you are not outputting 5V but more like 3.3V to them. This cuts down the current and makes it a lot safer.
19  Using Arduino / Project Guidance / Re: The easiest/best way to drive a Numitron (IV-9) with an Arduino Uno on: April 30, 2014, 04:04:52 pm
Not cool.

The  74HC595 are being massively overloaded beyond their specifications.

Should be using TPIC6B595s.


What about what you said here: http://forum.arduino.cc/index.php?topic=222825.msg1687256#msg1687256

I thought you meant that the 74HC595 could handle it. I think the 74HC595 can deliver a maximum of 20ma at up to 15V and the numitrons IV-9 needs between 17 and 20ma at 3.5V. (http://tubes-store.com/product_info.php?cPath=&products_id=494).

So should that not work?
20  Using Arduino / Project Guidance / Re: The easiest/best way to drive a Numitron (IV-9) with an Arduino Uno on: April 30, 2014, 07:50:53 am
Cool,

thanks for sharing smiley

21  Using Arduino / General Electronics / Re: Can someone help me pick the right battery/voltage regulator combo? on: April 23, 2014, 05:13:32 pm
Hi Chagrin,

Thanks a lot for your very clear explanation and taking the time to write down the whole process. I'm going to have to bookmark your answer for future projects!

I guess I'm going to need a bigger battery for this project as 4h of autonomy won't be enough. I was hoping to find a way to get 5 days of autonomy, that was a bit naive of me. I'm not even sure that will be possible.

I've learned something today and I will be going to bed less stupid smiley

Cheers!
22  Using Arduino / General Electronics / [solved] Can someone help me pick the right battery/voltage regulator combo? on: April 23, 2014, 02:58:41 pm
Hello,

I'm working on a project using an arduino Yun and there no regulator on it. So I started looking for battery, regulators, step-down/step-up regulator, etc... and now I just don't know anymore.

Here's my two founds after excluding the L7805 from my choices because of the 2V step-down thing.
StepUp/Down 5V regulator: looks pretty cool
http://www.coolcomponents.co.uk/5v-step-up-step-down-voltage-regulator-s7v8f5-1135.html
Battery 3.7V at 2000mAh
http://www.coolcomponents.co.uk/lithium-polymer-battery-2000mah.html

What do you guys think of that combo?

Also, a technical question. I always though that the higher the mAh the longer the battery will last before charge (obviously depending on what's sucking on it) but that feels a bit naive. I think I read during my search that higher voltage regulated to lower voltage will last longer than low voltage regulated to higher voltage. Even if the latter has a higher mah.

So I'm confused....and the analogy of the water only took me so far in understanding electricity.

I hope someone can help me pick the right one.

Cheers

ps: The arduino Yun seems to need around 250mah, a photodiode and IR led, I might also have a 2 or 3 leds,  and maybe four IV-9 numitron, which need something like 3.5V at 20mah apparently. So a total around 350mah maybe, hope that helps.
23  Using Arduino / LEDs and Multiplexing / Re: Is it possible: control Numitron IV-9 with MAX7219CNG LED driver on: April 19, 2014, 10:11:02 am
Hi Guys,

I'm currently looking into the same kind of things. I was wondering how it went in the end and if you could share some of your work or founds?

I first was attracted by Nixies but soon realised that managing 170V wasn't the best for me, and then found the Numitron! There're still cool and the IV-9 seems like the only one working on 3.5V to 4.5V.

Cheers.

ps: +1 Karma for Paul__B
24  Using Arduino / Networking, Protocols, and Devices / Re: new Twitter API - HTTPS always required on: June 22, 2013, 05:39:14 pm
Hi Christophe,

That's quite a good find. Thanks for sharing.
25  Using Arduino / Networking, Protocols, and Devices / new Twitter API - HTTPS always required on: June 15, 2013, 11:10:36 am
Hi,

On the 11th of this month, Twitter stopped some of their old API (like search.twitter.com) but most importantly, all of their API is HTTPS only.

This is a problem for arduino, as there's no ssl support as far as I'm aware (ram issue?). It's a shame, I tried to look everywhere for a arduino only solution but no luck.

The only solution is a proxy server (Arduino ask Server to make quiery Twitter's API). It's not as elegant, I was really enjoying having just an arduino board and no computer.

If anyone has a different solution or thoughts about it, that would be great.

Cheers

founds during my searches incase:
https://code.google.com/p/crypto-arduino-library/
https://polarssl.org/
http://www.yassl.com/yaSSL/Home.html

26  Using Arduino / Programming Questions / Re: CuHead/Uno R3 and Twitter on: June 14, 2013, 02:13:02 pm
@andersoncentral

If you are using "search.twitter", like me, than you might get into problems as Twitter spotted it on the 11th of June. You have now to use api.twitter.com/1.1/search, register your app, and do an auth. It's a bit more complicated as you need to submit two keys to get a token that you will include in your queries to the API.

I am starting to adapt my php test to arduino. Will post the results if I'm successful. 
27  Using Arduino / Networking, Protocols, and Devices / Re: [Resolved] Ethernet Board, client.connect(URL, port) only works with IP? on: May 26, 2013, 11:23:52 am
Cheers SurferTim,

I will check it out when I get to this part in my project. I will need some time to get my head around the code you putted on Playground.

Again, thank you very much for your help.
28  Using Arduino / Networking, Protocols, and Devices / Re: [Resolved] Ethernet Board, client.connect(URL, port) only works with IP? on: May 26, 2013, 08:09:15 am
I'm so happy about this I've got to thank you guys again. That was driving me insane! It's one of those things, it's right in front of you but you've been looking at it for long that you can't even see it.

Thank you!
29  Using Arduino / Programming Questions / Re: Ethernet and SD in the same sketch on: May 26, 2013, 07:55:34 am
Hi,

this worked for me:
http://forum.arduino.cc/index.php?topic=168374.msg1253159#msg1253159

Code:
void setup() {
  Serial.begin(9600);

  // disable SD SPI
  pinMode(4, OUTPUT);
  digitalWrite(4, HIGH);

  // now do the rest of your setup stuff.
}

thanks to SurferTim.
30  Using Arduino / Networking, Protocols, and Devices / Re: [Resolved] Ethernet Board, client.connect(URL, port) only works with IP? on: May 26, 2013, 07:52:34 am
SurferTim, you're the man!

I should have read the SD library doc in more details and realise that there's both using SPI communication.

So if I want to use the SD card to store information, I would need to switch on and off pin 4:

1/ switch off pin 4
2/ HTTP request
3/ store response in memory
4/  switch on pin 4
5/ write to card
(back to step 1)

Cool, I hope this will also help others. ( I can't believe how much time I wasted because of this).

Cheers!
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