really awesome robot idea

[m@]

so i had this really sweet idea and i need some help on the parts im not sure about. So i thought if i bought a really cheap sell phone, and wired it somehow that it would always answer. I would use a computer connected to a phone of my house to communicate with the robot. Now I would need to make some sort of modem to connect to the robot but i'll get to that. The main idea i have is to have a video camera transmitting composite video back threw the telephone to me and me transmitting back commands to the servo controller on the robot. So in the end i would be able to continuosly roam around outside with the robot from my computer.

 

Now to communicate with the robot is what i need help with

 

I know that on a telephone modem, there are usually 2 tones sent out by one computer over the phone line for 0's and 1's and the receiving computer sends back 2 different tones. Now i need a way so that i can connect to the servo controller threw the line and the camera to send compositve video back to me.

 

Does anybody know how i could do this, all i need to know is how i could build or get something that could transfer the info i need over the phone line

[Cap'n Refsmmat]

Do it like RC cars. They use many pulses to send commands, like 46 for forward, 16 for back (i'm making that up). So to pulse it and program the car to interpret them as commands. Voila!

[YT2095]

using 2 PPLs (phase locked loops) ie/ NE567 ICs.

set them to recognise and pass only specific tones (a handfull of components are all thats needed), then through a simple transistor, set the output of each chip to TTL or CMOS levels (your choice of chipset).

use one as clock and one as data, then all you need is SIPO converter chip, Serial In Paralel Out.

it works on clock and data, using an 8 bit chip (and they only cost pennies) you can have up to 255 different commands, that can be issued within microseconds

have Phun

 

cap, they work on PWM (Pulse Width Modulation) that controls the servos turn position, each function still has it`s own sub carrier though, the ideas there, but doesn`t work quite in the way you outlined

 

[YT2095]

on second thoughts, there`s an easier way!

 

buy a DTMF decoder chip (again only pennies) and follow the instructions that should come with it (or get them off the net).

then all you`de have to do, would be dial the bot, and enter in using your modile keypad (enable dial tones 1`st ) the code you wish it to perform

the output of the DTMF decoder can be either binary or decimal, depending on the one you purchase

[m@]

thanks dude your awesome, but i don't get what your saying about dialing 1's

[m@]

wait i see what your saying, that is really awesome. But do you know if i can transmit composite video back just by connecting it directly to the phone's microphone?

[m@]

http://www.jdr.com/interact/item.asp?itemno=GR-Clock

 

hows the second one, will it do the job. And on the chip can you program what it outputs threw the serial depending on the diferent tones?

[YT2095]

comp vid no, the mic input is heavily filtered and wont accept a signal above 3.5 Khz as a rule, comp wid is a much higher frequency.

the second chips sounds great it will be hex output and only needs 5 volts.

so if you took the outputs and wired them to LEDS you`de have 12 leds, and each would light according to whatever tone from your telefone it "Heard". it`s up to you what you use instead of leds, relays to switch motors or stuff I should Imagine

[m@]

so is that second one ok?

[m@]

woops didn't see what you said

[m@]

back to the led example, would it keep the leds on? would they go off as soon as it hears the tone again or something?

[Cap'n Refsmmat]

Depends on how you wire things.

[YT2095]

if you used TTL 7474 (dual JK flip flops) or a pair of 74373 (octal latches) you could keep the leds on untill presenting a new code. Ide keep one of the 12 functions as a reset or NO CODE option as well