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Author Topic: l293d connections  (Read 564 times)

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Offline sohailsamejaTopic starter

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l293d connections
« on: March 07, 2013, 12:25:39 PM »
is the connection in the diagram corect for the black line follower mode of the $40 robot.This is the actual way iam going to solder them im not using the dip pins please confirm whether this will work.
« Last Edit: March 07, 2013, 12:49:06 PM by sohailsameja »
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Offline Billy

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Re: L293D CONNECTIONS
« Reply #1 on: March 07, 2013, 12:43:56 PM »
Standard protocol for message boards is to use lower case type. Your all CAPS subject lines are stressing me out, man.
Go easy on the caps and I'll give consideration to answering your questions.

Offline sohailsamejaTopic starter

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Re: l293d connections
« Reply #2 on: March 07, 2013, 12:49:55 PM »
sorry,have changed it,just love the caps button and shift will go easy from now on.
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Offline sohailsamejaTopic starter

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Re: l293d connections
« Reply #3 on: March 08, 2013, 03:15:41 AM »
please confirm for pin 7 and 10 (does it go to vcc)
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Offline newInRobotics

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Re: l293d connections
« Reply #4 on: March 08, 2013, 04:47:58 AM »
In cases like Your's datasheet sure helps a lot --> http://www.ti.com/lit/ds/symlink/l293d.pdf ;)

If You connect everything as in the picture above two lower Half H-Bridges will be ON all the time and two upper Half H-bridges will be ON or OFF depending on output of Your sensors. All that means that if upper Half H-Bridge is OFF - motor spins, if it's ON - motors stops. If this is desired behaviour, then it's all right.
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Offline sohailsamejaTopic starter

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Re: l293d connections
« Reply #5 on: March 08, 2013, 05:42:35 AM »
Ok, im not really good with h-bridge termings i will just post the instructions from the original tutorial here.i dont have male header pins(impossible)to find hence i wanted a direst connection.
you will understand more below

in the above picture you can see the header pins are to be connected to pins 2 & 15(sensor input) and pins 7 & 10(input)
later in the tutorial 4 wires are cut and the following instructions are given
Quote
Once done, cut fivefour 5 cm long wires and add molex connectors to each using the method given at www.societyofrobots.com/electronics_wire_connector.shtml Solder two of these wires to the 1K resistors. From these wires we will get high or low inputs from the sensors to drive the motor Solder the remaining two wires to the red wire of the battery cap.

now these positions are seen below the ones to the battery cap are connected to pins 7 & 10 and the others to the latter.


my question is can i solder(join) pins 7 & 10 to 8 & 9 as it is to the + terminal of battery and solder pins 2 & 15 directly to the resistor to ease my work and hence not use header pins.The diagrem initially posted describes my plans on soldering please confirm that
Thanks

P.S:i will ONLY use it as a black line follower.
« Last Edit: March 08, 2013, 05:45:02 AM by sohailsameja »
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Offline newInRobotics

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Re: l293d connections
« Reply #6 on: March 08, 2013, 06:22:46 AM »
If You're asking if you can solder directly to the pin and skip the header - then yes, You can.
"Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music." - Kristian W

Offline sohailsamejaTopic starter

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Re: l293d connections
« Reply #7 on: March 08, 2013, 06:49:07 AM »
Thanks alot i will solder them directly to the pin,One thing i dont understand is why pins 7 and 10 are connected to (+) terminal(vcc) and usually its input from sensor array.Could you tell me
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Offline newInRobotics

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Re: l293d connections
« Reply #8 on: March 08, 2013, 07:46:33 AM »
I already partially explained it in one of my previous posts. Also, datasheet is Your friend, it explains it very well.

However, if You want to be spoon-fed, here it is ;D In Your application intention is to have each motor spinning only one direction (one clock-wise, another counter-clock-wise), to achieve that author decided to clamp one side of each H-Bridge HIGH (keep them constantly ON), that causes motor to spin to the desired direction whenever the other side of H-Bridge is OFF (internally connected to the GND). When top side (due to sensor signal) is switched ON, both sides of motor get equal voltage, hence potential voltage across motor terminals becomes 0V, hence motor stops.

It would be useful for You to better understand how H-Bridge works:
--> http://www.societyofrobots.com/schematics_h-bridgedes.shtml
--> http://www.dprg.org/tutorials/1998-04a/
"Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music." - Kristian W

Offline sohailsamejaTopic starter

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Re: l293d connections
« Reply #9 on: March 08, 2013, 08:35:27 AM »
thanks alot,most people tell me that pin 7 and 10 are usually for sensor input butthe author connected it to vcc,you explained me why.Thanks alot im ready to solder it that way and let me keep my fingers cross. :)
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Offline newInRobotics

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Re: l293d connections
« Reply #10 on: March 08, 2013, 08:41:31 AM »
Thanks alot im ready to solder it that way and let me keep my fingers cross. :)
Better don't hold Your fingers crossed while soldering, might ruin what You solder  ;D
"Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music." - Kristian W

Offline sohailsamejaTopic starter

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Re: l293d connections
« Reply #11 on: March 08, 2013, 10:15:00 AM »
 :) :D :) ;D
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Offline sohailsamejaTopic starter

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Re: l293d connections
« Reply #12 on: March 09, 2013, 12:16:32 AM »
Final Word

Pins 1,7,8,9,10 are connected to Red wire of battery cap(Vcc)
Pins 2,15 connected to sensor input(left and right respectively)
Pins 3,6,11,14 connected to left and right motors respectively
Pins 4,5,12,13 connected to blackwire of battery cap(Gnd)

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