Demo board on batteries?

Thomas Fletcher · 2009-02-25 17:37

I just purchased the propeller starter kit and I am already getting buyer's remorse. I have zero electrical background and my programming is old school
(Basic, Fortran, Cobol), but I wanted a new hobby.

Many questions. Many many questions.....but I was wondering first if the demo board can be ran off of batteries. I have a power source from a helmet camera
that uses 8 AA batteries but have no idea on it's output.

mctrivia · 2009-02-25 17:41

8x1.5=12v

or 6v double the current

either way it will work but be inefficient.

a switching supply would save battery life if you don't mind buying an extra module

Oldbitcollector (Jeff) · 2009-02-25 17:45

Hi Thomas:

Don't worry, you are in good hands here..

You've also picked a great board to work with!

The Propeller chip itself runs on 3.3v, but the regulators can handle higher voltage input.

8 AA batteries (at 1.5v each) is 12V DC. The regulators will handle this,
but it is a little more than I would be comfortable with for long term use.
(and the regulators will likely run hot. not good.)

If you feed anything from 6v-9v DC into the board, you should be in good shape.
I've run mine off 9v batteries. (Don't last more than 4-5 hours if you are using a screen.)
without issue.

Don't be afraid to ask those questions... [noparse]:)[/noparse]

Be warned, the Propeller is a seriously addicting hobby.
Say goodbye to family, friends, outdoors, co-workers, etc. [noparse]:)[/noparse] [noparse]:)[/noparse]

OBC

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New to the Propeller?

Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

Oldbitcollector (Jeff) · 2009-02-25 17:49

This is a good way to work with batteries..

www.adafruit.com/index.php?main_page=product_info&cPath=18&products_id=80

You can purchase this from Adafruit, or build one with a few parts from your local Radio Shack.
I've even seen small AA battery packs which have the 9v connector on one end so you can be more precise.

OBC

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New to the Propeller?

Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

SRLM · 2009-02-25 17:49

Welcome to the crowd! The first thing to do is to read through the Propeller manual, so you get an idea of how everything works (Prop wise), then the Propeller Education kit labs are a good place to continue.

If you do run it off of 12 volts, be sure not to draw too much current. If you feel the regulators heating up really hot (those two black squares by the USB port) then turn it off and remove some of the load.

For some of my questions about the propeller, see this thread: http://forums.parallax.com/showthread.php?p=765086

Some electrical engineering is helpful, but not required. Most of the Obex objects have the circuit diagrams built in, and with the demo board most of the work is done for you.

russ christensen · 2009-02-25 17:50

Being a complete beginner as well, although with some c++ experience helping, this hobby is very very addicting. I second OBC saying, you are in good hands here. Main thing is don't be afraid to ask questions, but be as detailed as possible. [noparse]:)[/noparse] I have had a tremendous amount of help from everybody here that has really jump started my self education. These guys know what they are doing, listen closely to them.

Russ

Thomas Fletcher · 2009-02-25 17:54

It will run off one 9V battery? That is great news. I have a 9v connection here somewhere.

Thank you!

After getting the basics down, my first project I wanted to make was a "magic compass" that points to a geocache instead of north
using the digital compass, gps, and a servo.

Mike Green · 2009-02-25 17:54

It works fine off batteries. As mctrivia noted, it's not very efficient when run from a 10-12V supply since most of the power just gets turned into heat in the 5V regulator. Best is to run it off a 6 x AA NiMH rechargable battery pack which has a 7-8V output through most of the discharge cycle. You could run it off a 5 cell NiMH battery pack which would output about 5.7-7V.

Oldbitcollector (Jeff) · 2009-02-25 18:05

Excellent project! When I go geocaching with my PPDB board, I use a simple battery connection.
(Use a DC powerpack for your development process, then switch in the battery for the road.)

Take your time to "start with the basics" with the Propeller and enjoy the adventure in learning.

Mike's suggestion for a rechargeable pack is solid and will keep you from investing in battery stocks. [noparse]:)[/noparse]

BTW, I'm "oldschool" (note my forum name) too. You'll get up to speed in no time.

OBC

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New to the Propeller?

Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

rokicki · 2009-02-25 18:45

I love the magic compass idea! Personally, I'd use a small screen rather than a servo (think: you could put distance on it too,
maybe some uncertainty information). For the screen I might use one of the small graphical LCDs that parallax sells, or if you
want to splurge, the OLED module that is available. Even simpler would just be three LEDs, one for "straight ahead", one for
"turn left" and one for "turn right" with various blink rate cues for distance and/or how much to turn.

grasshopper · 2009-02-25 19:00

I am running mine off a 9v. Its the easiest way to run it off a battery that I have found.

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Post Edited (grasshopper) : 2/25/2009 7:05:45 PM GMT

Thomas Fletcher · 2009-02-25 19:16

That is what is on my desk right now, Grasshopper!

rokicki, I thought about using a screen but I wanted it to be a little more "Pirates of the Caribbean" with a physical needle. I use an IPAQ with bluetooth GPS now and GPS tuner software which
only provides bearing information when moving (no digital compass) which gets confusing when you make small turns or turn in place.

grasshopper · 2009-02-25 19:56

Yea I intend on using a 2x20 LCD screen in an effort to making it portable.

That is a spark fun mini mod GPS breakout board and its working quite well. It displays Altitude, longitude, latitude, speed and time of course. I must admit that the speed has not been tested since i have not made it portable yet.

I have found that using a 2x20 LCD display - with battery's I can run it "surprisingly" for quite some time.

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Oldbitcollector (Jeff) · 2009-02-25 20:15

He's got limited pins with the demoboard, so I'd recommend a 4x20 Serial LCD module.

OBC

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New to the Propeller?

Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

Thomas Fletcher · 2009-02-25 20:20

8 AA batteries (at 1.5v each) is 12V DC

Hmm I have an off topic question to show my complete ignorance but it has been bugging me for some time since the
idea of kinetic seaweed first popped into my head.

If you had enough AA batteries could you ever produce a megawatt of electricity? Or is it like two separate things?

Kinetic seaweed was an idea to string billions of the Seiko Kinetic Watch mechanisms together in mile long beds near shore.

grasshopper · 2009-02-25 20:29

@ Thomas Fletcher
Yes you could make a megawatt out of AA batteries. This would require some batteries and bit of time to do, but nothing is impossible. Stun guns crank out high Voltages - say 50 kV up to 1000kV Volts mix this with some current (1 -10 Amps) eventually you'll get a megawatt. I think most use 9V bats.

@ Oldbitcollector
I am running a 2x20 off of 6 pins so its not to bad. 4 Data pins and 2 for CS and (RW if i remember correctly.) The remaining pis are for power ground and backlighting so no propeller involvement needed on them.

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mctrivia · 2009-02-25 20:30

yes 1 million in parallel would give you 1 megawatt if using lithium cells

mctrivia · 2009-02-25 20:32

stun guns have no current behind that voltage.

grasshopper · 2009-02-25 20:34

mctrivia said...
yes 1 million in parallel would give you 1 megawatt if using lithium cells

I totally disagree.

If one was to take a few battery's AAs - modulate a signal into a transformer, storing the voltage in a capacitor network you would begin to increase the voltage to high numbers. The next step would be to add a little current. I don't think that 1 million batteries would be needed.

Maybe 1 million in parallel gives you a Mega-volt.

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mctrivia · 2009-02-25 20:44

1 million in parallel gives you 1.5 v each cell gives you 1 amp

mctrivia · 2009-02-25 20:47

yes you could build s marcs generator and for a nano second provide 1 megawatts off s single cell

grasshopper · 2009-02-25 20:52

Thomas Fletcher said...

If you had enough AA batteries could you ever produce a megawatt of electricity? Or is it like two separate things?

To understand better the answer

P=IV and since MegaWatt = 1^6P then no matter how you get I(current) and V(voltage) its all the same thing.

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Thomas Fletcher · 2009-02-25 21:03

And I am lost. hehehe

Started reading on voltage and current and the best I could comprehend was that voltage is the push and current is what is being pushed?

So like does a city need a certain ratio of the two or could the megawatts be all voltage?

mctrivia · 2009-02-25 21:12

the power in your house(if in north america) is a 120v sin wave.

p loss=i*i*r

so if the distribution system likes to go higher voltage to lower I since r of wire is expensive to reduce

Mike Huselton · 2009-02-25 21:27

I just shorted out a quantum nucleonic battery and it doesn't seem

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JMH

Thomas Fletcher · 2009-02-25 21:45

Here is some info on the Seiko kinetic watch but I haven't found out what it's power output is.

What Seiko has done is, in effect, to install a miniature power plant in each Kinetic watch. What the Kinetic movement does is capture natural energy from the movements of the wearer's arm, amplify it, store it and use it to power the timekeeping mechanism. It is a triumph of microminiaturization. Seiko filed more than 50 patents for the Kinetic project.
The heart of the Kinetic system is the rotor. A tiny thing, just 2.66 mm in diameter and 0.4 mm thick, the rotor (technically, a samarium cobalt microrotor) spins at astonishing speed - 10,000 to 100,000 revolutions per minute, five times faster than a racing car engine.
The wearer's arm movement causes an oscillating weight to rotate. Gear trains transfer this movement to the rotor, whose spinning generates voltage across a coil block. That's electricity. The electrical current is stored in a tiny component called the ESU ('electrical storage unit') and is released when needed to power the watch.

Demo board on batteries?

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