next topic »

[on:]

I searched through Google and the Arduino Forums for info on this topic but I couldn't find a definitive answer on whether or not this will work.

I will be using 4 Towerpro 9805BB Servo 160g / 20kg / .20sec servos

specs: The 9805 is a large double bearing servo, often used for scale planes and large boats. Very high toque with oversized internal components.

link: http://www.hobbyking.com/hobbyking/store/__7366__Towerpro_9805BB_Servo_160g_20kg_20sec.html

9805BB      
Weight: 160g
Dimension: 66*30.2*64.4mm
Stall torque: 20kg/cm(4.8V )C25kg/cm(6V)
Operating speed: 0.20sec/60degree(4.8v), 0.16sec/60degree(6v)
Operating voltage: 4.8-7.2V
Temperature range: 0~55 Celcius
Dead band width: 5us

Battery: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=21220

Zippy Flightmax LiFe batteries deliver full capacity & discharge as well as being the best value batteries in the hobby market today!

The Zippy Flightmax 2500mAh LiFe Receiver pack provides unequalled voltage stability and lighter weight than stock receiver batteries. Ideal for the latest high torque, high speed servos that require more current.

Spec.
Capacity: 2500mAh
Voltage: 6.6v
Constant discharge: 5C
Burst discharge: N/A
Weight: 132g
Size: 131x32x18mm
Discharge plug: EH
Balance plug: JST-XH

I don't believe I'll need any sort of voltage regulator because the battery will be operating within the specs of the servos. Here is a picture of the wiring diagram I plan on using (but instead of one servo, there will be four running from the same battery). Also, I want my board to be portable so it must be battery powered as well, any ideas? Any help would be appreciated! Thanks, Mike

[Reply #1 on:]

yes - from the info u displayed wouldnt see why not

[Reply #2 on:]

yes - from the info u displayed wouldnt see why not

Awesome! What battery would you recommend to power my Arduino UNO board? I heard some people were using 9v batteries, but they didn't last very long. Any ideas?

Will this work to power the board? http://www.hobbyking.com/hobbyking/store/__23681__ZIPPY_Flightmax_1800mAh_3S1P_30C_LiFePo4_Pack_USA_Warehouse_.html

ZIPPY Flightmax 1800mAh 3S1P 30C LiFePo4 Pack

Spec:
Capacity: 1800mAh
Voltage: 3S1P / 9.9v
Discharge: 30C Constant / 40C Burst
Max Charge Rate: 2C
Weight: 194g (including wire, plug & case)
Dimensions: 137mm x 45mm x 16mm
Balance Plug: JST-XH
Discharge Plug: XT-60 Connector



UNO board requires:

Microcontroller   ATmega328
Operating Voltage   5V
Input Voltage (recommended) 7-12V
Input Voltage (limits)   6-20V

How long do you thing the will last the board? I would like it to run for at least a few hours.

[Reply #3 on:]

If the above battery wont power my UNO board for a full day, will this battery work better?

http://www.hobbyking.com/hobbyking/store/__16590__Turnigy_3800mAh_3S_20C_LiFe_Pack_Long_USA_Warehouse_.html

Spec:
Minimum Capacity: 3800mAh
Configuration: 3S1P / 9.9v/ 3Cell
Constant Discharge: 20C
Peak Discharge (10sec): 30C
Pack Weight: 403g
Pack Size: 180 x 42 x 28mm
Charge Plug: JST-XH
Discharge Plug: 4mm Bullet-connector

Also, does anyone know the type of convertor this guy is using on the end of his battery? I think I will need something like this.



(this is the battery used in the above pic, but I thought it was kind of on the low side power wise, http://www.ebay.com/itm/battery-lipo-KingMax-500mAh-7-4v-25C-RC-mini-model-new-Free-Shipping-/230782766368?pt=Radio_Control_Parts_Accessories&hash=item35bbb98d20)

Thanks, Mike

[Reply #4 on:]

Hi,
   You seem to be mixing and matching your battery technologies, some are LIFE and some are LIPO, you need to make sure that your charger can handle both types, mine can only do LIPO so thats what I use.

A 2S 8.4 volt LIPO will power your Arduino through the power jack as in your picture. The same type of battery with a higher capacity will also power your servos no problem.

I am not convinced that using a 2 cell LIFE battery at 6.6 volts is a good idea. Most servo specifications warn that running them at 6 volts as opposed to 5 volts will shorten their life, you are pushing this further and can expect subsequently shorter servo life, the standard approach in RC is to run servos from a 8.4 volt LIPO connected to a 5 or 6 volt high current regulator.

Heres an example (not a recommendation - seen cheaper) - http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXSWL3&P=ML

Duane B

rcarduino.blogspot.com

[Reply #5 on:]

Also, does anyone know the type of convertor this guy is using on the end of his battery? I think I will need something like this.



(this is the battery used in the above pic, but I thought it was kind of on the low side power wise, http://www.ebay.com/itm/battery-lipo-KingMax-500mAh-7-4v-25C-RC-mini-model-new-Free-Shipping-/230782766368?pt=Radio_Control_Parts_Accessories&hash=item35bbb98d20)

Thanks, Mike

Ha, that's my picture I got the connector from Tayda electronics -> http://www.taydaelectronics.com/hardware/dc-power/dc-power-plug-2-1mm-x-5-5mm-x-9-5mm-right-angle.html I use the 500mAh battery to power my "Arduino remote control" -> http://www.bajdi.com/arduino-remote-control/remote-control/

[Reply #6 on:]

Hi,
   You seem to be mixing and matching your battery technologies, some are LIFE and some are LIPO, you need to make sure that your charger can handle both types, mine can only do LIPO so thats what I use.

A 2S 8.4 volt LIPO will power your Arduino through the power jack as in your picture. The same type of battery with a higher capacity will also power your servos no problem.

I am not convinced that using a 2 cell LIFE battery at 6.6 volts is a good idea. Most servo specifications warn that running them at 6 volts as opposed to 5 volts will shorten their life, you are pushing this further and can expect subsequently shorter servo life, the standard approach in RC is to run servos from a 8.4 volt LIPO connected to a 5 or 6 volt high current regulator.

Heres an example (not a recommendation - seen cheaper) - http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXSWL3&P=ML

Duane B

rcarduino.blogspot.com

I'm a complete noob when it comes to batteries so I really appreciate your help. I'm a little confused on what voltage will harm my servo. If I got a battery that produced 6.6v and my servos operating voltage is between: 4.8-7.2V how will 6.6v harm my servos? Is it better to always stay on the lower voltage recommendations? (I'm not challenging you, I'm just trying to understand this better.)

When my final build is complete I will be powering the 2 servos (Operating voltage: 4.8-7.2V)

9805BB      
Weight: 160g
Dimension: 66*30.2*64.4mm
Stall torque: 20kg/cm(4.8V )C25kg/cm(6V)
Operating speed: 0.20sec/60degree(4.8v), 0.16sec/60degree(6v)
Operating voltage: 4.8-7.2V
Temperature range: 0~55 Celcius
Dead band width: 5us

1 UNO board requires: Input Voltage (recommended) 7-12V

Microcontroller   ATmega328
Operating Voltage   5V
Input Voltage (recommended) 7-12V
Input Voltage (limits)   6-20V

I'll be using 6 - 4 PIN LED
http://www.radioshack.com/product/index.jsp?productId=3097460&CAWELAID=174884615

and about 15-20 standard LEDs

I would really like to use one high capacity battery pack.


I wasn't able to find the battery you recommended but I did find this LIPO battery. Do you think this would power everything, or should I try finding one that's closer to 8.4 volts.


Would this battery be ideal at 7.4 volts or should I go up 11 volts and use a bunch of voltage regulators? http://www.hobbyking.com/hobbyking/store/__20680__Turnigy_nano_tech_6000mah_2S_25_50C_Lipo_Pack_USA_Warehouse_.html

I selected a battery with a Constant Discharge of 25C because that's what I saw Bajdi use. Let me know if you recommend something different! Thanks Again! Mike

[Reply #7 on:]

(this is the battery used in the above pic, but I thought it was kind of on the low side power wise, http://www.ebay.com/itm/battery-lipo-KingMax-500mAh-7-4v-25C-RC-mini-model-new-Free-Shipping-/230782766368?pt=Radio_Control_Parts_Accessories&hash=item35bbb98d20)

Thanks, Mike

Ha, that's my picture I got the connector from Tayda electronics -> http://www.taydaelectronics.com/hardware/dc-power/dc-power-plug-2-1mm-x-5-5mm-x-9-5mm-right-angle.html I use the 500mAh battery to power my "Arduino remote control" -> http://www.bajdi.com/arduino-remote-control/remote-control/

Thanks for the link! How long did the battery last you? Also, do you remember where you got the battery plug receiver that you used to make your DC power-plug? Thanks, Mike

[Reply #8 on:]

Hi, regarding the servo voltage, if the specs say 7.2 then that's fine, most say 5 to 6 volts, but the servos you have selected are clearly designed for more. A fully charged lipo puts out 8.4 volts, dropping to 7.2 as it discarges. When LIPOs first came out a lot of RC car guys damaged servos because they had been getting away with connecting 6 volt servos directly to 7.2 volt nimh batteries, but the step up to 8.4 was a step too far. Running you 7.2 volt servos at 8.4 might be ok, but is outside the stated limits I suggest you weigh up the cost of replacing two servos against the cost of a 6 volt regulator.

You can run the Arduino from the same battery as the rest of the project, I usually connect mine into the balance plug on my LIPOs.

Duane B

rcarduino.blogspot.com

[Reply #9 on:]

Hi, regarding the servo voltage, if the specs say 7.2 then that's fine, most say 5 to 6 volts, but the servos you have selected are clearly designed for more. A fully charged lipo puts out 8.4 volts, dropping to 7.2 as it discarges. When LIPOs first came out a lot of RC car guys damaged servos because they had been getting away with connecting 6 volt servos directly to 7.2 volt nimh batteries, but the step up to 8.4 was a step too far. Running you 7.2 volt servos at 8.4 might be ok, but is outside the stated limits I suggest you weigh up the cost of replacing two servos against the cost of a 6 volt regulator.

You can run the Arduino from the same battery as the rest of the project, I usually connect mine into the balance plug on my LIPOs.

Duane B

rcarduino.blogspot.com

Thanks for the clearing that up! So a 7.4 LIPO will output 8.4 volts when fully charged? That's strange! lol

I think I found the battery you recommended, it's a 6000mAh 2S2P 7.4v 25C. There is a similar model that outputs 30C also. Which one would you recommend for this project?

25C: http://www.hobbyking.com/hobbyking/store/__19169__Turnigy_6000mAh_2S2P_7_4v_25C_hardcase_pack_USA_Warehouse_.html

30C: http://www.hobbyking.com/hobbyking/store/__17272__Turnigy_nano_tech_5800mah_2S2P_30_60C_Hardcase_Lipo_Pack.html

Also, I found the 6 volt Voltage Regulator for the servos (http://www.amazon.com/Common-Sense-RC-VR-6-Regulator/dp/B004DEOW3U/ref=sr_1_1?ie=UTF8&qid=1337004115&sr=8-1)

So, I can hook the battery directly to my UNO by connecting a DC plug convertor to the battery, and run my servos by running a 6 volt voltage regulator from my battery to the servos. Do you think I could also power my LED's with this battery, or should I get a separate battery dedicated just to the lights? And do you have any idea on the type of voltage regulator I would need for my LEDs? Thanks again for your help! I really appreciate it! :-)

[Reply #10 on:]

Hi,
that's a nice small regulator, but two amps is not a lot of output current, I have seen similarly priced units with six or more amp output. If size is not an issue and you think you might build something more demanding in the future go for a high current regulator.

as for batteries I don't use the higher capacity batteries they are at the limits of the technology and are always less reliable, you should be fine around 4000mah, 5 or more is pushing it.

Edit: LEDS will be fine provided you use current limiting resistors.

Duane B
rcarduino.blogspot.com

[Reply #11 on:]

Hi,
that's a nice small regulator, but two amps is not a lot of output current, I have seen similarly priced units with six or more amp output. If size is not an issue and you think you might build something more demanding in the future go for a high current regulator.

as for batteries I don't use the higher capacity batteries they are at the limits of the technology and are always less reliable, you should be fine around 4000mah, 5 or more is pushing it.

Edit: LEDS will be fine provided you use current limiting resistors.

Duane B
rcarduino.blogspot.com

OK, I found these two regulators that outputs 8 amps, which one do you think would work better. Also, do you think that a battery with 25C is sufficient? Or should I go with a 30C battery?

http://www.ebay.com/itm/160640999693?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 (doesn't come with a switching-mode DC-DC)

http://www.ebay.com/itm/260961965981?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 (comes with switching-mode DC-DC)

Here is the battery: http://www.hobbyking.com/hobbyking/store/__20998__ZIPPY_Flightmax_4000mAh_2S1P_25C_Car_Lipoly.html

Spec.
Capacity: 4000mAh
Voltage: 2S1P / 2 Cell / 7.4v
Discharge: 25C Constant / 30C Burst
Weight: 235g (including wire, plug & shrink wrap)
Dimensions: 138x47x23mm
Balance Plug: JST-XH
Discharge plug: 4mm Bullet-connector

I researched the LEDs and I came up with these two wiring diagrams. (which way do you think I should wire up my LEDs, #1 or #2?) I plan on connecting it to my 6 volt power regulator.

#1 Is of a parallel wiring diagram



#2 Is the websites "GURU" recommended wiring diagram

[Reply #12 on:]

HI,
Circuit number two with an individual resistor for each led.

An even better option is to connect parallel sets of two or three LEDs in series. You still need a current limiting resistor for each parallel set but it's more efficient.

Are the LEDs going to be on all the time or will they be controller by the Arduino ? If you want to control them you might need additional components.

Duane B.

[Reply #13 on:]

HI,
Circuit number two with an individual resistor for each led.

An even better option is to connect parallel sets of two or three LEDs in series. You still need a current limiting resistor for each parallel set but it's more efficient.

Are the LEDs going to be on all the time or will they be controller by the Arduino ? If you want to control them you might need additional components.

Duane B.

These 6 LED's will be controlled by the Arduino UNO. I want them to turn on when the servo is at 0 degrees, and turn off when the servos moves to 180 degrees. Any ideas on the additional component's that I'll need to achieve this?

[Reply #14 on:]

Hi,
   To drive six LEDs from a single pin, you have lots of options. I usually use a standalone (DIY) Arduino for this interfacing with my RC Cars in which case I have access to the LIPO voltage before and after the regulator, if I was going to drive six LEDs from a single pin I would connect two parallel sets of three series LEDs, these would be connected to the unregulated 8.4 volts from the lipo through a current limiting resistor (one for each paralllel set of three series resistors) and then through an npn transistor to ground. The Arduino would drive the NPN transistor which would effectively be acting as a switch to turn the LEDs on and off.

The good news for you is that your Arduino UNO also gives access to the unregulated 8.4 volts through the vin pin. If each LED has a voltage drop of around 2 volts, you can connect three in series, two sets of these gives you your six volts.

Rather than me try and explain this, have a look at this link -

http://led.linear1.org/led.wiz

put in the following values and see circuit 2

8.4
2
15
6

Your LED voltage drop (value 2) is probably going to be different, I will leave it to you to figure out where or how to find this out.

Duane B

rcarduinob.blogspot.com