Building a wifi robot (Work in progress)

[cinaed666]

Hey people, I'll be posting the progress on my final highschool project here. It's a wifi-controlled robot, with a streaming camera.
basicly, I gutted a big old RC car, and used an arduino ethernet along with a motor controller I designed for this purpose and a linksys router to make it happen.
I kept the 9.6V (actually about 10.5V when fully charged) LiPo battery that clicks in the bottom for convenience, since I have two and a charger, and it doesn't take a lot of place.
Right now, I'm able to control it over command line, since it's running a telnet server from which I can control the output pins.
In the end, I want to be able to have a user-friendly program that interfaces with the telnet server, show the streaming camera image, and take joystick inputs.


Motor controller using L293B ICs and an LM7806 to feed both the ICs and the Arduino.
I opted for a 6V instead of 5 since there was a voltage drop because of the load, it's actually outputting just over 5V, whereas an LM7805 was only giving me about 3.5V


WIP


Testing out the telnet sketch


Everything fitting snug.


I'd love to hear some feedback. Also, what would be the best "transformer" IC to up a voltage from about 9-10V to 12?
I guess this would do? http://www.national.com/pf/LM/LM2621.html#Overview

[keeper63]

What do you need the 12 volts for - the router? Whatever, it would probably be easier and better to get a couple of 7.2 volt packs, wired in series (make a "y-cable" that allows for this, so you can disconnect each to charge the batteries), then drop the voltage down with a 7812 regulator (and if you need the current, use a bypass transistor - or even better, see about getting a drop-in 3-pin switching regulator for 12 volts). Ultimately, you're likely to get a better system with a longer runtime going that route. So far, though, your machine is looking great!

[zoomkat]

I did some tinkering with making a simple web controlled routerbot at the below link. The bottom link is to a web cam that has a similar control setup.

http://www.lynxmotion.net/viewtopic.php?f=20&t=6343

http://web.comporium.net/~shb/wc2000-PT-script.htm

[cinaed666]

What do you need the 12 volts for - the router? Whatever, it would probably be easier and better to get a couple of 7.2 volt packs, wired in series (make a "y-cable" that allows for this, so you can disconnect each to charge the batteries), then drop the voltage down with a 7812 regulator (and if you need the current, use a bypass transistor - or even better, see about getting a drop-in 3-pin switching regulator for 12 volts). Ultimately, you're likely to get a better system with a longer runtime going that route. So far, though, your machine is looking great!

Yep, I need 12V for the router. I'm considering your solution, but the up-voltage IC would be easier to add to the controller at this point.

[keeper63]

What do you need the 12 volts for - the router? Whatever, it would probably be easier and better to get a couple of 7.2 volt packs, wired in series (make a "y-cable" that allows for this, so you can disconnect each to charge the batteries), then drop the voltage down with a 7812 regulator (and if you need the current, use a bypass transistor - or even better, see about getting a drop-in 3-pin switching regulator for 12 volts). Ultimately, you're likely to get a better system with a longer runtime going that route. So far, though, your machine is looking great!

Yep, I need 12V for the router. I'm considering your solution, but the up-voltage IC would be easier to add to the controller at this point.

How much current does the router need - have you measured this? The part you referenced states that it can supply a maximum of 1A (I also wonder if a heatsink will be needed for that part, as well as what that does to the voltage level of the battery - and how that will effect the rest of the system)...

[cinaed666]

How much current does the router need - have you measured this? The part you referenced states that it can supply a maximum of 1A (I also wonder if a heatsink will be needed for that part, as well as what that does to the voltage level of the battery - and how that will effect the rest of the system)...

I haven't measured it, but after doing some googling, I read it's supposed to use about 5-6 Watts, so half an amp.
I don't think the rest of the system should be affected, the upped 12V isn't going through the other components, just feeding the router, parallel on the battery.

[keeper63]

I haven't measured it, but after doing some googling, I read it's supposed to use about 5-6 Watts, so half an amp.

If that's true, then it will probably be ok...

I don't think the rest of the system should be affected, the upped 12V isn't going through the other components, just feeding the router, parallel on the battery.

I was thinking more like if you were operating close to the maximum of 1 amp, whether there would be a voltage sag that could cause other things connected to the battery to behave wonky...

[cinaed666]

What do you need the 12 volts for - the router? Whatever, it would probably be easier and better to get a couple of 7.2 volt packs, wired in series (make a "y-cable" that allows for this, so you can disconnect each to charge the batteries), then drop the voltage down with a 7812 regulator (and if you need the current, use a bypass transistor - or even better, see about getting a drop-in 3-pin switching regulator for 12 volts). Ultimately, you're likely to get a better system with a longer runtime going that route. So far, though, your machine is looking great!

I found out the router will run on less than 12V, since it regulates the input voltage down to 3.3V anyway. So, I'm feeding it with the 10-ish V battery.

We decided to build in the router, since it fits snug in the roof compartment. We extended the antennas with TNC cables, and made them pop out of the back window. They're nice and secure, and still turnable, and easily removable. If anything, we're getting a better signal.

[praneeth]

hey cinaed666... !!! happy to see ur uploads on this .. my final is project is also very similar... can i know exactly how ur sending signal signal to ur arduino from ur laptop?? we are using java script to send and i find certain delay in sending continuous signals... and wat is the capacity of the battery which you are using?? 

[Jantje]

Great project and great looking result.
I'm currently also working on a wifi controlled robot. I've opted for a netgear but that has caused me some headaches already (the memory buffer in the netgear is to small). The router solution you use would fit me better.
Keep up the good work

Praneeth
I guess the network delay will exist in all cases. This is why I want a sensor to overrule external commands. This to avoid running into trees and walls. I have been told this is not so good for a robot 

Best regards
Jantje

[pprovazky]

That´s absolutely awesome! Great job!

[praneeth]

hey Jantje .... i have also tried different routers...try linksys.. it works fine...

[cinaed666]

It's time I post an update here.



I fitted the network camera, and made it run off the battery. I modified my windows program to stream the camera's image in there.
I've got some issues with the front servo still, might have to swap that out, and we're fitting a bigger battery in the back compartment, since the original one can't take it.
that is all Except for those things, it works pretty smoothly!

[cinaed666]

hey cinaed666... !!! happy to see ur uploads on this .. my final is project is also very similar... can i know exactly how ur sending signal signal to ur arduino from ur laptop?? we are using java script to send and i find certain delay in sending continuous signals... and wat is the capacity of the battery which you are using??  

Right now it runs on a 9.6V 950mAh ni-cad battery, but it's not enough to run it for a long time. So we're swapping it out for 2 12V lead-acid batteries daisy-chained together.

The signals are ASCII bytes sent from a vb.NET program via the TELNET protocol.
The arduino emulates a basic telnet server, and depending on which byte it recieves, it will do different actions. (Make other digital pins HIGH or LOW). The digital pins are connected to my motor controller, which will make the motors do certain things depending on the input.

[cinaed666]

Great project and great looking result.
I'm currently also working on a wifi controlled robot. I've opted for a netgear but that has caused me some headaches already (the memory buffer in the netgear is to small). The router solution you use would fit me better.
Keep up the good work

I used a belkin first but that gave me issues as well Well not so much the memory buffer, as the lack of reverse-current protection that made me blow it up, haha. Oh well, the linksys is a much better choice. So much mods for them, too.