Curious to know how this turned out.

I am kind of scared to try it out.

I'm not.  Ordered one today, will let everyone know how it works out.

Thanks

No, I am talking about my random circuit.

It seems to work OK on stackoverflow!

...R

You have alot of complaints about this site.  Why don't you start your own and stay there.

Are you talking to me?

You can make a simple pushbuttom switch with a 4013:

http://ernstsite.wordpress.com/2-2/

Before I got Arduino, I had this electronics kit with a 4013 counter chip and a quad NAND gate chip. There was a particular circuit that used the 4013 to flip-flop switch LEDs with push button. Thanks for reminding me!

Curious to know how this turned out.

I am kind of scared to try it out.

Compiler given personalities? Great idea! As long as you can adjust it. I don't like how all compiler errors are so robot-like.

can measure their current draw when you're running them directly from the battery?

Yes. The current wildly fluctuates between 1.2A and 0A when the wheels are off the ground. Stall current is steady at 1.2A.

You could add a capacitor in parallel to the battery near the motors.

What kind of capacitor and where should I put it?

As to your first question, feel free to furnish a schematic.

This is the current schematic. If I connect the motors parallel directly to the batteries bypassing the Arduino, the motors spin very fast. There is also a spark when I connect the power. I have no datasheet for the motors. The motors are connected to wheels powering a four wheel drive skid-steering robot. Even without load, the motors struggle to spin.

Hello forum!
I was trying to power 2 DC hobby motors with a 500mA NPN transistor each, along with an Arduino UNO. The power source was 4x AA Alkaline batteries, all relatively new. However, the motors were struggling to move, and the Arduino was constantly restarting.  I used my multimeter to measure the resistance of the motors. Both were 2.5 ohms. So, does that mean that the batteries do not have enough current output to power 2 motors and an Arduino?
Another question: is it possible to combine 2 transistors to double the current output (e.g. 200mA transistor + 200mA transistor = 400mA transistor?)
BTW, I know Ohms law.
Thanks in advance! If my explanation is unclear or missing details, please politely point it out.

Hello!
I have a suggestion for the forum: when people have quick questions that can be answered in only one post, they don't need to make a whole new thread just for that. Instead, why not there be a "Quick Questions" sticky thread in each board? Or even a "Quick Questions" board in the General category?
I await you opinion!

P.S. I have a quick question that you might be able to answer: I measured the resistance of a DC motor on my multimeter. It was 2.5 ohms. So would that resistance change if I apply more voltage to it? Or will it stay the same (at 5V, it will use 2A.) By the way, it is just a regular hobby DC motor.

I copied this one: http://www.clear.rice.edu/elec201/Book/images/H-bridge4.gif
I wired it the same way as shown in Reply #2 of this thread.

My first idea was to get an identical IR phototransistor (ambient sensor), place it facing up on the breadboard to measure the ambient IR light and "subtract" it from the other IR phototransistor (proximity sensor), but I can't get my hands on any new components anytime soon. So I posted this to see if people will suggest other methods.

Oh yeah, my transistor H-Bridge with 500 mA NPN transistors are not working. See my picture in my first reply. What is wrong with the circuit? I checked the wiring and everything.

I have a new logo design for the non-profit organization Solar Energy International http://www.solarenergy.org/. I am not affiliated or related; it was a school assignment. What do you think? Is it worth selling (LOL)? Don't plagiarize me (I made it in Blender).

Qualities (my opinion):

   Solar Energy International is an educational and empowering organization. In order to create a healthy and sustainable environment on Earth for future generations, SEI strives to educate as many people as possible about environmentally friendly energy sources and technology. As more people are educated about this topic, renewable energy use will be more widespread. This energy is very sustainable, which will make the Earth a more clean and healthy place for people and the environment.

    SEI is also an innovative organization. Instead of actually building renewable energy plants, SEI takes a more systemic approach for widespread renewable energy use and sustainable practices. By educating people around the world, more and more people can use sustainable energy and technology in more places. This is an innovative way to encourage worldwide renewable energy use.

   SEI is a peaceful and humble organization. They use a very practical and effective approach to reaching their goals, and don’t have to be particularly vocal, bold, or rambunctious. This is unlike some other organizations, which use violence to deal with problems.

   SEI is a collaborative organization because they work with grassroots and development organizations which share the same vision in order to spread their impact on the world. SEI is also collaborative because they get a lot of people from all walks of life to get involved in using renewable energy.


Rationales:
Image / Symbol: The light bulb represents SEI’s innovation. The light bulb was an extremely important innovation in the history of technology, so it is a good symbol of innovation. It can also be a symbol of education because it is knowledge is needed for innovation. The ring of people is representative of SEI’s collaboration with other organizations. It also represents the people who SEI educates about renewable energy (representing SEI’s educational value).

Colour: Since the bottom of the background is dark, and the top is lighter where the Earth is, it looks like the Earth is being raised out of darkness. The soft glow indicates positivity and hope, which represents SEI’s goal of creating a better world through education and renewable energy. The colours of the people are the primary colors of light. This is saying that the people of Earth are the basic building blocks to a better world full of renewable energy and sustainable technology.
   
Font: This simplicity and regularity of the font symbolizes SEI’s simple, but effective method of education, and the unique letters symbolize the innovation in SEI’s techniques that separate it from other organizations.

Shading: The people are bright colors because they have the power (education) to make the environment better for everyone. The Earth is “glowing” because it is being “raised out of darkness” by all the educated people working together to make the world a better place.

I don't know if your method would work, but the Arduino can measure its own working voltage with this code: https://code.google.com/p/tinkerit/wiki/SecretVoltmeter.

Hello!
I have built an makeshift IR Proximity Sensor. I have written an article (incomplete as of now) about this sensor: http://arduino720.wikispaces.com/Infrared (last article). This makeshift sensor consists of a 880 nm IR Emitter placed right beside a IR Phototransistor. Both components are facing forward. The emitter sends out a ray of IR light, and the phototransistor picks up the ray of light when it bounces off objects in front of it. The phototransistor is covered with a piece of grabge bag plastic to filter visible light, minimizing interference from visible light sources inside the house. In a room lit with energy-saving bulbs at night, the sensor has a range of about 5 cm. However, the IR Phototransistor receives a considerable amount of interference when exposed to sunlight. I know that there are IR Range Finders (e.g. Sharp GP2D120) on the market with high resolution and range, with very little interference and function similarly. How can I change my makeshift sensor to cut out interference from sunlight?
Thanks!