Content in “Electronics”

IR and pulsin

CaptainTuna — Sun, 05 Oct 2008 10:47:14 -0400

After some time of idleness i got to work again on my IR setup. I still have some problem understanding what happens.

This is my setup:

Transmitter: picaxe28x1, IR led (tsal6100)with cathode connected to pwm (%50 duty, 38000Hz), anode to an output pin.

Code:

pwm bla bla (set up of pwm)

pause 500

pulsout 7, 250

Receiver: picaxe28a, IR receiver and demodulator (tsop1238) properly connected.

Code:

debug

main:

pulsin INPUT_PIN, 0, w0

goto main

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Ideas for motor speed control

GroG — Sun, 05 Oct 2008 00:54:34 -0400

I have an idea of how to do a electronic speed control for some DC motor (H-bridges).
I built this circuit and it works pretty well. Its a PWM generator based on this great tutorial . I had to convert it to a NE556 instead of a NE555 but it works well with a 100K linear pot..

How do i use this... (underside of a button)

MaltiK — Sat, 04 Oct 2008 09:35:30 -0400

how do I solder a wire to this so that I can use a microcontorller to trigger it via outputs?

Anyone have any experience with an ooPIC?

GroG — Fri, 03 Oct 2008 10:32:48 -0400

Seems a bit expensive, yet looks to have a pretty extensive compiler.

http://www.oopic.com/whatsnewin6.htm

Analog multiplexor (possibly i2c)

Nicola — Mon, 29 Sep 2008 15:27:40 -0400

Hello! i have almost finished my analog inputs on my last project.. i have only one left and i need to attach some potentiometers to do some calibration.. I could really use some nice multiplexing. What i'd like is a chip with some analog inputs and possibly an i2c interface so that you can choose which analog pin to read and get a digital reading. Do you know if anything like this exists ?

Does anyone know the Wiring I/O board?

mintvelt — Thu, 25 Sep 2008 15:44:51 -0400

Does anyone have any experience with this board? I found it on maximum robotics and it looks really cool. 128K, 8! analog inputs and 6 PWM ports all on one board.

I haven't found a lot about the programming environment, but it looks promising.

PWM not causing motor to turn until 50%

Setix — Thu, 25 Sep 2008 09:55:02 -0400

I built a Pulse Width Modulator to control the speed of a 12V DC motor, but the motor doesnt even turn until the potentiometer is at 50%. How can i fix this?

Let me give more background. I took apart a Skil 12VDC 1 Amp Drill and removed the motor, gearbox, transmission, and chuck all in a single unit, and wanted to control that motor much like the trigger on the drill did...slow to fast, at full torque.

wanted: fm stereo receiver

rik — Wed, 24 Sep 2008 08:39:49 -0400

This is an electronics question that has little to do with robots. But this forum seems a good place to ask it anyway.

For an upcoming diy project, I am in need of some advice on integrated radio circuits. For my 93 yr old grandmother I hope to build a radio that can do this:

Stupid question on ampere and motors

Nicola — Mon, 22 Sep 2008 09:11:45 -0400

Probably a stupid question: if i have a motor driver that can handle at most say 1 A per motor, and two motors that consume say 2 A when stalled, what will happend when they stall? Will the robot simply underpower, or the motor controller burn, or what else ?

What is Needed for a Circuit to Recharge Batteries

jklug80 — Thu, 18 Sep 2008 11:30:24 -0400

Has anyone made a circuit that recharges batteries without having to take them out of your bot and put them in a charger? I would like to be able to plug my bot into an ac/dc adapter and charge it without having to remove the batteries.

I am assuming you have to use caps to keep voltage in check as well as determine when the batteries are fully charged to keep them from being damaged.

Also I'm not sure what I don't know ;) Anyone have any suggestions or experiences with this?