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Topic: Arduino Yun with batteries (Read 17467 times) previous topic - next topic

Kimcha

Hi,

I would like to build a little accessory that starts a WiFi network (accesspoint mode) and then redirects all HTTP requests to a html page served on the arduino. The HTML page has a link to a file which could be up to 300mb big, which should be downloaded to the clients.

I want this little accessory to be battery powered. I simply want to take it with me, press a button to turn it on, connect a device, download the file and then turn the device off again (or let it turn off automatically if possible).

I could not find any information or tutorials of people powering their Arduino Yun from batteries. Is it energy efficient enough to do that?

Greetings, Kim

toggio

I succesfully use the Yun with battery, and i have to say that is quite battery efficent. The power consumption is around 1.25W. So with two 2500mAh NiMh AA battery and an adeguate step up power supply it could last up to 4 hours.

Kimcha

That is amazing. I am a complete newbie with arduino. Could you tell me which components you used to connect the batteries and what I would need?

If you have followed some how to or tutorial could you please link me to it?

toggio

You just have to supply +5V to the Vin PIN of the Arduino Yun, so you can use every form of power supply rated @ 5V DC.
Ore you can use the onboard microUSB connector connected to a USB powerbank.

Kimcha


NDBurn

I suggest that you use a regulated power supply. Check out http://www.therpf.com/f24/iron-man-motorized-faceplate-led-eyes-circuit-please-help-me-check-185628/ - it is easy to build.

Cheers,
Andy

fermino

#6
Oct 13, 2013, 01:47 am Last Edit: Oct 13, 2013, 02:18 pm by fermino Reason: 1
do someone knows how much tolerant of the voltage the yun is (possibly both under and over 5V)?

I mean, if it is not too fuzzy, just using four 1.2V NiMH and it should last more than 4 hours, no upconverter needed.

NDBurn

Good question, I wondered too. However, in the description it says

<quote>
If you are powering the board though the Vin pin, you must supply a regulated 5VDC. There is no on-board voltage regulator for higher voltages, which will damage the board.
<unquote>

and also in other texts it is warned not to regulate the Yun. Therefore I prefer to use a regulator to be on the safe side.

Cheers

cloudyun

Hi ...

I intend to power Arduino Yun using batteries and I have tried a couple of approaches :

1. I have tried a 9 V battery along with LM 1117 (LDO - 5 v fixed output) based voltage regulator circuit. The Arduino Yun run for about 3 minutes and then it turns off. I have tested the current drawn by Arduino Yun while it is powered ON and found it to be in the range of 250 mA. I think this large current might be responsible for rapid discharging of the 9V battery.

2. I then experimented using 12V, 2 A NiMh battery with the same LM 1117 based voltage regulator circuit. This time the Arduino Yun powers and operates perfectly. However, the LDO IC LM 1117 dissipates a lot of heat and the IC gets heated.

I want to know what circuit should I use to provide a regulated 5V DC for powering the Arduino Yun.

Please advise on the type of regulator to use and about designing the power circuit.

Thanks. 

ProfePaco

#9
Dec 02, 2013, 12:54 pm Last Edit: Dec 02, 2013, 01:01 pm by ProfePaco Reason: 1
I find theses regulator very cheap and reliable:

http://www.ebay.es/itm/Buck-Converter-Step-Down-Adjustable-Converter-Power-Module-Regulator-LM2596-v-h9-/221297710921?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item33865f1749

http://www.ebay.es/itm/LM2596-DC-to-DC-Buck-Step-Down-Converter-Module-Voltage-Regulator-Red-Voltmeter-/310670105406?pt=LH_DefaultDomain_0&hash=item4855619b3e


http://www.ebay.es/itm/0-9V-5V-to-5V-600MA-DC-DC-Booster-Module-USB-Mobile-Step-up-Power-Supply-Module-/171127900936?pt=LH_DefaultDomain_0&hash=item27d8048b08


stid

#10
Dec 02, 2013, 03:22 pm Last Edit: Dec 02, 2013, 03:56 pm by stid Reason: 1
I have just tested a setup based on Arduino Yun. This is what I'v learned so far (I'm still testing):

My setup include a voltage regulator based on this example (LM317): https://www.sparkfun.com/tutorials/83.

1) 9V Alkaline Battery -> LM317 regulator -> 5V to arduino vin pin
Arduino Yun is completely unstable. It hangs with led 13 flashing for a while, then stop working after some seconds. No way to connect via WiFi.

2) 4 Alkaline AA Battery (6V) -> LM317 regulator -> 5V to arduino vin pin
Arduino yun work for some seconds, but as soon as you stress it by accessing web pages on the httpd and the SD card, the SD card itself became unstable and fail to serve some files. In this setup the problem seems to be related only to the linino side and related HW components. I think also that in this specific case, the 6V is too low to be correctly regulated via LM317.( They suggest > 2 Volt as input).

3) 7.2V from external power source (8-900 mA)  -> LM317 regulator -> 5V to arduino vin pin
Arduino works like a charm, serving web pages, talking via I2C with another arduino and acting as remote control for a robot. Tested for hours in this way.

In all these setup I'v read the voltage output from the regulator and it was stable at 5V. This is why I think the problem was related to current drag.

All the setups above were also tested with a standard Arduino Mega and Uno and I had no problems at all with them. (obviously without wifi support and embedded linino).

My perception is that the yun can drag a huge amount of current depending on the resource you are going to use on the linino side (web server, sd card access...). Standard battery with low current are not able to serve it in a stable way. You should probably try to power the Yun with a NiMh 7.2V battery or similar  (800 or more mA) to avoid stability problems.

I should say I'm everything but an electronic pro, thus keep my assumption accordingly,
hope this could help in your project in any case,
thanks,
stefano.

francisrmd

How can you factory reset a Yun?  I tried roughly #1 above and it seems to have fried it (I tried it before I saw this post).

muellerp

#12
Feb 12, 2014, 10:03 am Last Edit: Feb 12, 2014, 10:07 am by muellerp Reason: 1
The higher the difference between the source voltage and the input voltage of the Arduiono, the more preferable is a step-down controller over a linear controller.
"ProfePaco" shows here the right way.
Step-Down regulators are more efficient.

Using a 12V battery with the Yun an a "linear regulator":
5V for the Yun
7V for the Regulator
0,25A drawn bei the Arduino

5V * 0,25A = 1,25W for the Arduino
7V * 0,25A = 1,75W for the regulator -> very much heat
This means 3W for the battery.

step-down regulator:
90% efficiency
1,25W for the Arduino
1,4W for the battery (calculation is not quite correct, but ok)


Do not use LM317 when the voltage gap ist too big.

valeriou

HI Guys,

I am not sure if it could be of any help but I am using a Samsung Galaxy charger and plug it into the Yun usb. As far as I know it should be a regulated 5V - 1A. Everything seems to work fine.

Valerio

cipri92

I ordered a 230 AC to 5V 1A DC power supply from eBay. Based on what the Valeriou said, I think it should work fine for a Yun. Just to be sure, does the Yun draw the needed current from that 1A or is it too much?

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