will these work? PLEASE LOOK!

system · May 24, 2008, 11:44am

hi everyone!

well iv been serverly bored lately so im going to actually spend some money and do a project (a elabrate car remote/ electronic key).

i have a few questions before i buy mainly if the stuff i want will actualy work:

is this tranciever compatible with arduino? http://www.sparkfun.com/commerce/product_info.php?products_id=153# if so i will buy 2 for communication between each other.

am i able to use the attiny13 with arduino (without the bootloader) http://www.sparkfun.com/commerce/product_info.php?products_id=211 otherwise can you please point me to some smaller microcontrollers as i dont want the remote to be to big (itl only be 2 buttons with wireless and a few wires coming out the front) otherwise ill just use the atmega168

wil the MAX1555 constantly power the microcontroller while switching between charging and running off battery? also which switcher should i use if i dont use lipo batterys as i would pefer to use a littler battery (3v rechargable cell)

how would i make it if its plugged into the "car" as a key that it only sends the codes throught the wireing to the "cars" controller and not over the wireless?

getting more random now...

if it works and well (unlikely(ill probably give up by then :P)) i would like to do it properly onto a pcb so here are the new questions:

is there any reason i cannot use the Crystal SMD 16MHz over the normal non smd chip?

also where is a good site that sells SMD components (resistors ect)

another thing with the random code

heres my code:

void setup(){
Serial.begin(9600);
}

void loop(){
  Serial.println(random(100000000, 999999999));
  delay(20);
}

so extremely simple just produce a random number between 100000000 and 999999999 (so the output is always that many digits long) the problem is it never goes random for the whole thing. so heres an example output

if someone can help me so i can make it so it is using all the numbers for randomness.

thanks heaps in advance :D

callum

Grumpy_Mike · May 28, 2008, 8:52am

is this tranciever compatible with arduino?

Yes but you will need an Ardunio with each trancever.

am i able to use the attiny13 with arduino (without the bootloader)

No this is not compatible. you will have to program it separately if you want to use it.

wil the MAX1555 constantly power the microcontroller

Yes this, and a battery, and some switch over diodes.

how would i make it if its plugged into the "car" as a key that it only sends the codes throught the wireing to the "cars" controller and not over the wireless?

Yes, modulate the signals at a high frequency say at 100KHz, and capacitative couple onto the wiring. Demodulate at the other end.

is there any reason i cannot use the Crystal SMD 16MHz over the normal non smd chip?

Not that I can see.

also where is a good site that sells SMD components (resistors ect)

:- Farnell

another thing with the random code

so extremely simple just produce a random number between 100000000 and 999999999 (so the output is always that many digits long) the problem is it never goes random for the whole thing. so heres an example output

If this code is in the Arduino then it is limited to the number of bytes assigned to variables. If in Procesing then you need to use floating point variables.

Just a point, if you are having to ask these questions then I think that this project is maybe a bit too advanced for you, try doing some of the tutorials first and work your way up to this. :'(

system · May 30, 2008, 3:56am

thanks man yer it is probabily 2 advanced 4 me but 2 late i have oreded 2 trancievers and some other parts so waiting for them to arrive and figured out the random problem a guy helped me fix that

system · June 4, 2008, 5:49pm

how would i make it if its plugged into the "car" as a key that it only sends the codes throught the wireing to the "cars" controller and not over the wireless?

now this idea I like .. i can think of quite a few times this would have made my life sooooo much easier. Cheers to the idea !!!!!!! Les .... custom automotive floor mat

system · June 5, 2008, 8:50am

haha yer it would be quite cool

now im sure a few where expecting this so...

has anyone interfaced the arduino with the nrf2401a tranciever http://www.sparkfun.com/commerce/product_info.php?products_id=153

trust ,iv got them then actualy look at the example code and its al in pic form (grrr)

help appreciated

haha gota laught at my stupidity

cheers callum

system · June 16, 2008, 10:28pm

how would i make it if its plugged into the "car" as a key that it only sends the codes throught the wireing to the "cars" controller and not over the wireless?

now this idea I like .. i can think of quite a few times this would have made my life sooooo much easier. Cheers to the idea !!!!!!! Les .... custom automotive floor mat

Hello everyone, Wow, that is a great idea, much better security that way!! The hackers may have some trouble with that plan, or not??

auto insurance

system · May 6, 2021, 6:49pm