View Full Version : RF Receiver question

07-28-2006, 04:26 AM
i tore apart one of those gigantic RC cars made by Jada toys (the dub city escalade) and the receiver is +3 volts, GND, and SER

what can i do to read what its reading, what baud rate.... and once i figure that out with serin im going to replace it with my homework board with serout and make it roam autonominously(or whatever) thanks for the help!

Beau Schwabe
07-28-2006, 05:05 AM

Serial data formats can vary GREATLY. This is probably not RS232 serial as you are expecting to see.
It is more likely a simple MARK/SPACE pulse ratio train that is being transmitted serially. What kind of
functionality does the RC car have?

Do you have a scope? This will be the easiest way to determine what kind of pulse is actually being used.

Beau Schwabe (mailto:bschwabe@parallax.com)

IC Layout Engineer
Parallax, Inc.

07-28-2006, 05:07 AM
this thing has various functions, front back left right, it has 3 speeds (low medium and high) a horn, Music button, and a Lock button


what type of chip would be on it if its going serially like i presumed?
looking at it there is not much to it.... theres a coil quite a few capacitors and a few things labelled c1815gr5f with three prongs comming out and no i dont have a scope unfortunatly yet can i use the board kind of like a scope possibly with stamplot lite

Post Edited (willthiswork89) : 7/27/2006 10:11:45 PM GMT

07-28-2006, 05:36 AM
what resistor would i use so i dont fry the board and can at least test some things out

07-28-2006, 05:48 AM
alright this is really wierd but the car has a switch which goes to the main board with the channel but the RF receiver is completly disconnected from the switch.... it wont matter but all i gotta do it figure out the poulses and imitate them with my board possibly with a 555 timer... if you need pics ill gladly take them!

07-28-2006, 11:58 AM
alright apaon further inspection there is a try me where the remote works inb the box it has a CLK and DA...thats serial correct?

Beau Schwabe
07-28-2006, 12:15 PM

CLK and DA ... could indicate that it is serial of some kind, but it doesn't really narrow it down to anything we can make sense of.

I2C has CLK and DAT, but so do the pins on a shift register ... the protocol is completely different between the two. We really need
more information here.

Beau Schwabe (mailto:bschwabe@parallax.com)

IC Layout Engineer
Parallax, Inc.

07-28-2006, 12:25 PM
alright im leaning more towards getting rid of the mother board the car uses and replacing it completley with the homework board.... from what my info has gathered the steering uses a chip with mettal tochers... (like push buttons) when the motor turns it either has a high on left a high on right or a high on both, basically meaning left right and centered. as for the back motor which is a fairly big motor (approx. 1 1/2 inches in diameter, 3 -4 inches in length) is run by these two things that are black square boxes that say Tianbo 05 VDC
12a 120VAC
10a 240vac
7a 240vac

the serial is HJR-21FF-S-Z

looks like two transformers? i dunno any input would be appreciated...thanks Beau

there it is... its a PC board Relay? i can desolder them if i can use it on the homeworkboard if they are necessary... thanks guys


Post Edited (willthiswork89) : 7/28/2006 5:29:32 AM GMT