Author Topic: Arduino...Not enough power pins! (Read 4426 times)

blackheart · « **on:** March 15, 2009, 02:40:51 AM »

Hello! Yesterday, I ordered some sharp ir rangefinders(2) and I realized that there was no way I was going to plug them in together with the motor controller. Arduino only has 3 power pins.

While writing this, I also realized I don't have enough ground pins. Only 2...or 3.

I could get a protoshield, but it would take weeks until I get it!

I could get a roboduino, but it would also take weeks.

It could get here in few days if I paid $100 or more on fast shipping.

What can I do?

Let's say I power the motor controller only from external sources, but this still wouldn't work as I need 2 sharp ir rangefinders and arduino has one 5v pin.

I AM F****D!

Have a nice day!

want2learn · « **Reply #1 on:** March 15, 2009, 03:14:14 AM »

You could make up a power wire by getting some old (or new) flyleads and splicing them together remembering to heatshrink the soldered parts of the wires to prevent shorts.

Another option is to make up a small sheild yourself, It's not that difficult and requires minimal components.

Just remember not to draw too much from the arduino power bus, can't recall offhand how much the onboard regulator can cope with but after deducting the arduino's power consumption I think it'll be on the order of 750mA ish

SmAsH · « **Reply #2 on:** March 15, 2009, 03:17:02 AM »

you could do what want2learn said or make your own 5V regulated bus and have a row of say 5X3 header pins and have
jumpered signal
+5V
gnd
much like the roboduino.

blackheart · « **Reply #3 on:** March 15, 2009, 04:15:06 AM »

This is very hard to ask, but I didn't find much on google about it. Probably because I didn't know what to look for!

How do you make a power bus? SmAsH's power bus thing is great because I also need grounds, but I don't know much(actually, I don't know anything at all) about power buses.

thank You Both!

SmAsH · « **Reply #4 on:** March 15, 2009, 04:22:11 AM »

ok ill draw up an idea and upload it shortly. sorry, eagle wasnt doin it for me today $:-\$

blackheart · « **Reply #5 on:** March 15, 2009, 04:46:37 AM »

Thank You very much! I will see what I can do!

SmAsH · « **Reply #6 on:** March 15, 2009, 05:16:58 AM »

always happy to help

now that i think about it you could use those header pins that have a longer underside so it could be plug in and play sorta thing?

blackheart · « **Reply #7 on:** March 15, 2009, 05:31:14 AM »

Wait. While analyzing the scheme, I found out that I have another question. Why did you go with the red + wire and the gnd wire through all the holes/pins?

to show the direction, or does it have to make contact with all of them?

And, if I plug something in the first pin/hole, will the other still have current from the 5v source?

Razor Concepts · « **Reply #8 on:** March 15, 2009, 06:48:03 AM »

It has to go through all the pins in its row.

Why don't you use a breadboard? That is what most Arduino users do.

SmAsH · « **Reply #9 on:** March 15, 2009, 01:09:36 PM »

Quote from: blackheart on March 15, 2009, 05:31:14 AM

Wait. While analyzing the scheme, I found out that I have another question. Why did you go with the red + wire and the gnd wire through all the holes/pins?

to show the direction, or does it have to make contact with all of them?

And, if I plug something in the first pin/hole, will the other still have current from the 5v source?

if you add an extra 2 pins inline with the gnd and +5V you can jumper it from a board or external source. and all the power and gnd are in buses. this allows the power to be shared between servos/sensors evenly. it has to make contact with all of them (just bridge the solder connections)

Quote from: blackheart on March 15, 2009, 05:31:14 AM

And, if I plug something in the first pin/hole, will the other still have current from the 5v source?

how do you mean? do you mean the signal on the arduino of the jumpered board? if so yes i still will as long as its still connected to power.

Soeren · « **Reply #10 on:** March 15, 2009, 01:19:37 PM »

Hi,

Pretty easy to do with Wire Wrap.

SmAsH · « **Reply #11 on:** March 15, 2009, 01:31:17 PM »

what exactly is wire wraping? is it just wraping wires around pins?

Soeren · « **Reply #12 on:** March 15, 2009, 01:43:20 PM »

Hi,

It might seem so at first sight, but the tool and the techniche used assures a better connection than soldering, since each corner of the square pin is actually welded due to the extreme pressure in the sharp corners.
The pin is usually soldered to the rest of the circuit, so you won't escape the resistance of a soldered connection, of course, but that way you can keep it down - and you can get IC sockets for WW as well, but they're expensive.
For semi-temporary bridging of coding pins or similar, it's aces.

Further, Wire Wrapping is quick in prototyping and it is relatively fast to change as well (unless we're talking logic circuits of the seventies with tonnes of discrete logic ICs, where you might loose track of which goes where, if you don't mark everything).

blackheart · « **Reply #13 on:** March 15, 2009, 05:25:16 PM »

Oh, why don't I use a breadboard? DON'T get me started about how much my country blows, because I will waste too much space on this forum!

PEOPLE IN HERE NEVER HEARD OF BREADBOARDS!

P.S. I am still confused about the power bus.

Maybe, it's because:
a) I am a retard
b) I am drunk
c) I am too lazy to think
D) ALL OF THE ABOVE

THE answer is, obviously...D!

SmAsH · « **Reply #14 on:** March 15, 2009, 07:08:37 PM »

power bus is just a row of pins soldered together to get rid of each pin needing a wire to the regulator

blackheart · « **Reply #15 on:** March 16, 2009, 02:19:39 AM »

thank you. I think I understand now.

TrickyNekro · « **Reply #16 on:** March 16, 2009, 02:58:53 AM »

You may have a good option but... depends on what you really want man...
Basically you can NOT make a arduino shield cause of the pin layout...
It's not symmetrical at some points.... and this can cause some problems...
You can rebuild the whole board with the power bus you want in some protoboard...
then use the RX TX for boot loader programming... Simple or not... it's a option...
Also you can use breadboards!!!!
Nice things for prototyping!!! But when it comes to a nice contraction it's a no no...
Can cause noise problems, and so on... (which will affect some ADC readings and some other things...
But the controller would be still operational....)
Whatever you want...

I usually use a breadboard for prototyping and then build the circuit somewhere more stable...
Basically there are many many options... it's up to your skills.... really...

SmAsH · « **Reply #17 on:** March 16, 2009, 03:40:50 AM »

tricky, do you mean the gap in between the different signal rows?

TrickyNekro · « **Reply #18 on:** March 16, 2009, 03:45:47 AM »

yup... it's 1mil not 2 as it must....

SmAsH · « **Reply #19 on:** March 16, 2009, 03:55:48 AM »

well you could probibly make an individual shield for each set of pins or make a custom pcb with weird ass hole spacings. but id probibly go with the first one $:-\$

blackheart · « **Reply #20 on:** March 16, 2009, 03:58:27 AM »

The power bus seems fairly easy to make, and I have the right materials.

OOh, there is one more question? On that drawing you made, SmAsH, why does the source have 3 pins? Most batteries have 2 pins

I have to find a 5v battery or get 4 1.5V batteries which I have near me right now, but I need to drop from 6v to 5v.

What Amperage are we talking about?

Max and Recommended?

SmAsH · « **Reply #21 on:** March 16, 2009, 04:05:03 AM »

that 3 pin thing is the regulator, you can use one if you want protection but if you trust your batteries you can leave it out

and what exactly do you mean by amps? like the battery needs to supply? going to be drawn?

blackheart · « **Reply #22 on:** March 16, 2009, 04:11:02 AM »

The amps the batteries need to supply. What exactly are the output specs on the arduino on the 5v pin?

I need the same(or very close).

SmAsH · « **Reply #23 on:** March 16, 2009, 04:14:44 AM »

i wouldnt really worry about that unless:
your batteries are 10,000 years old

or your going to be running high current draw servos.
to fix these problems you can chuck in a cap and/or use a regulator.
otherwise dont you think the roboduino would be screwed with normal battery packs?

essentially thats what were doing to this board.

blackheart · « **Reply #24 on:** March 16, 2009, 05:53:49 AM »

hey. does the ground. black wire, run through all 3 pins or just the first 2? can the regulator provide constant 5v from 6v battery? And also, where do I plug in the wires from the battery? On the top of the regulator? I am a total noob. I never used one before, and don't have any experience with making circuits, other than plugging in servos and sensors

SmAsH · « **Reply #25 on:** March 16, 2009, 02:06:02 PM »

the black (gnd) wire runs through one row of 5 headers in my picture. same with the red. RED AND BLACK WIRES DO NOT TOUCH!! the regulator is polarised, if you have the steel bit closest to you right is input and middle gnd and left output. wire it like the diagram. and yes the regulator can provide constant 5V but if you are not sure you can put a cap in there somewhere.

blackheart · « **Reply #26 on:** March 16, 2009, 04:29:39 PM »

Thank You! This is a retarded proof schematic. I am ashamed at myself, but I am also roflmfao when I am seeing the message. THIS IS YOUR BATTERY!!! on the schematic. I imagine you yelling MOTHER*****R and drawing it in paint

Thank you, I got it now, for real!

I just don't know where to find headers, so I will have to improvise? A metal plate with plastic separators?

SmAsH · « **Reply #27 on:** March 16, 2009, 05:36:07 PM »

you should be able to get the headers somewhere. otherwise you cant connect sensors to your port. most electronics stores have them

blackheart · « **Reply #28 on:** March 17, 2009, 07:50:02 AM »

nope. i looked at the only electronic store in my city and they dont have headers. what can i use instead?

sonictj · « **Reply #29 on:** March 17, 2009, 01:01:32 PM »

Make sure you use at least a 7.2 V battery to power the regulator on the arduino. Even if 6v is enough to make the regulator output 5v, your battery voltage will drop as the battery discharges. Example: a 5 cell NICD battery will have a charge of 6+ volts at full charge, but will drop down to ~5.5 when discharged. A higher voltage pack will keep your robot from doing bizarre stuff as the battery gets drained.

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Author Topic: Arduino...Not enough power pins! (Read 4426 times)

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