Use the square pad and the middle pad.

Thanks Howard for previous reply.

I believe there is an error in the BOM, for reference C67 & C68 it says quantity 4 but only 2 are needed?

Hello Howard,

For the serial connector, im looking at schematic and I dont see any information about it.

At jumper J65 (square) I assume is data?, what pin does it goto on the serial db9? (TXD 3) ?

and round to what pin on db9?

Yes, the quantity for 22pF is incorrect.

J65: square pad is data out, round is ground. The wiring for the DE9 will depend on what you are connecting to, but here are some typical connections:

http://pinouts.ru/SerialPorts/Serial9_pinout.shtml

thanks for the reply. I am connecting to the serial port of a Laptop or PC to use with timing software.

So it would be pin 3 & 5 on serial connector? (TXD & GND)

I'm using pins 2 and 5 to connect to the Sabrent SBT-USC6M USB to Serial Adapter Cable.

If you are using FlipSide scoring software, you will also want to connect pin 1 (square pad) of J66 to the incoming RS232 data (pin 3 on the DE9, in my case). This was a last-minute change requested by FlipSide; any character received by the decoder will reset the internal timebase counter.

Im not sure i understand why your using pin 2 on the serial connector since thats to receive data, isnt the decoder sending data to PC ? so it should be pin 3 (transmit data) ?

Thanks for the clarification on Flipside! I dont think im going to use it so far looks like i will go with Zround timing.

The labeling is for the connector on the PC. The PC receives data on pin 2, so that's where the decoder needs to send it.

silly me! i had things backwards, i fully understand now. thanks for clearing that up.

It's not just you! If I had a dollar for every time I've had to unsolder and swap RS232 transmit and receive lines, I'd be sitting in Hawaii right now.

ok i feel better now!

I dont know if this was asked before, how far can the decoder be from loop amplifier? or how long can the coax wire to the loop amplifier?

thanks!

If the coax is of good quality, with relatively low loss, then you should be able to run at least 75 feet.

My Decoder is complete! so far everything looking good! Loop Amplifier is next.

http://hostingforcanada.com/denny/ca...ot_decoder.jpg

http://hostingforcanada.com/denny/ca...orking_600.jpg

Hi ppl, i´m building a Cano Decoder, and i need a pcb for this decoder, so, anybody have a extra pcb that can sell to me? I have pm 2 members that have pcbs but no answer till now, please is urgent, the chip programmed pics are on way. Paypal or bank transfer, shipping to Portugal. Thank you :)

Same here, I'm looking for 1 or 2 pc boards for the decoder. Anyone have extra?

Thanks

I have extra Rev_B Decoder PCB, please PM me for details.

Hello Everyone,

I put together a WIKI site with the approval of Howard. The Wiki is currently maintained by myself and contains much of the information found here along with some of my notes as i go along with my build.

Cano Lap Timing System Wiki

The Wiki is meant to be able to find all useful information you need in one easy place without going through all the posts in the threads.

So far i have section for Decoder, Loop Amplifier and Loop. The Transponder i will not get too until later.

If your interested in contributing to the wiki and want to help then please contact me!

Hello Howard,

I have completed my system, it is not picking up transponder. On my terminal screen there is nothing happening and led on decoder is not flashing when transponder passing under loop.

i have measured voltage at coax from decoder and it fluctuates alot anywhere from 4.66 - 4.79v , i dont think it should be changing that much?

If i measure voltage at at loop amplifier outputs it is a constant 0.57v

what validations can i do?

thanks for any help.

The first step is to make sure you have taken care of all of the errata items:
http://www.rctech.net/forum/12186635-post222.html

Next, make sure you are using the correct loop amplifier jumper settings to match up with the loop size.

Also, make sure you are using a compatible transponder!

Then we get down to the nitty-gritty: You can check the voltages on the loop amplifier against those on the schematic. Small deviations are inevitable, but large differences warrant further investigation.

Then trace the signal with an oscilloscope. The output should look similar to that in post #42:
http://www.rctech.net/forum/11764084-post42.html

If everything looks good here, then continue the signal tracing through the Phase Detectior Input Amplifier, which should finally come out as a nice squarish waveform at "PHASE_DETECTOR_IN".

I have done all of these except the last item i am unsure of, could you explain this ?

"J1 is shown incorrectly on the schematic. The outer shield should connect to ground, and the inner conductor to R1." ?

Yes i have the jumper set for correct size.

yes i am using 2 wire Mylaps Hybrid

for this i will need to involve someone else to help with this.

Use an ohmmeter to make sure you have J1 wired as described.

Was the schematic corrected since then?

So the Rev_B boards are not correct? for J1 and R1? i simply soldered 2 pins in J1 and connected on to that, this is incorrect from what i understand?

"Correct" is a relative term when there are only two connections, both of which accept wires. Make sure you wire the outer shield of the connector to the square pad at J1 and the inner conductor of the connector to the round pad at J1 on the revision B circuit board. Double-check with an ohmmeter as previously described.

The connector is shown correctly on revision C and D of the schematic, which is what I sent in the zip file. It is shown incorrectly on revision B of the schematic. I just edited post #222 to state this.

yes i am using the correct pads for for connector J1 as you described.

i will check with ohmmeter.

Howard,

I measured voltage directly on decoder board and its a stedy 4.79v , so it turns out it was the connecter, i soldered a new coax connecter and better wire directly to the board and getting some voltage at the end of coax wire now.

Now for the loop amplifier, i believe i have my capacitor backwards at C4, is the round pad ground ?

Also can you confirm for J2 on loop amplifier the square pad is ground?

thanks !

Yes on both. C4 positive is the square pad, ground is the round pad. J2 square pad is ground.

Hello Howard,

I have rebuilt a second loop amplifier. Now my reading is 0.90v on the wire. I am suppose to have 1.20v as per your specs, where did i go wrong? As mentioned before i am getting 4.79v out of the decoder to the loop amp.

Still not working, no detection of transponder on the decoder.

I dont have any access to oscilloscope at the moment.

what else can be checked?

First do a visual inspection of all components. Some of them have polarities that must be observed. We've already mentioned the capacitor. Check the transistors also; emitter must go to the square pad. (You can download spec sheets for the components from Mouser or Digikey.) Reversed transistors could easily explain the voltages you are seeing (since the current gain of a bipolar transistor isn't too good when the emitter and collector are swapped!).

Next would be an inspection of all solder joints. It's pretty easy to bridge connections on the loop amp board.

Anything past that will require an oscilloscope.

Hello all,
Newbie to RCTech forum here. I am in the process of building an FPV Quadcopter, this is just an FYI. I am not an expert RCr by any stretch of the imagination. But I am very much interested in the Transponder design and Lap timing decoder Howard Cano started a while back, this is great stuff. I come from a Karting and Legends racing prep techman background and have always wanted to build an accurate DIY timing system, so I googled lap counting and timing Transponder. and the search led me to this fantastic site and very informative thread. I do have a back ground in electronics, RF and satellite comms for 25+ years. If you know anything about the Atlanta Area, you can probably deduce my previous employeer not the one that begins with M but the other one, the used to be leader in the Cable industry prior to a certain west cost company buying and selling off all parts of the once very successful company as well as releasing some very skilled engineers that pretty much made the company the leader it was in the cable world. I have some free time now and I would very much like to make myself available to help out on this project. Thanks to all for the great insight into the transponder timing world. Howard I will be sending you a PM shortly begging for whatever you have avail. on these two projects, schemos, board layouts, BOM's, theory of Operation, PC Boards, Kits, pre programmed MCu's, etc..

Regards
MAC55

Thank you Howard for the recommendations. I have looked at both boards and so far all my transistors seem to be correctly installed, i am comparing with your picture.

On the decoder board I did find i was missing 2 capacitors at C3 & C4 ! wow i cant believe I forgot those. Well no change still not working and voltage at the loop is the same.

thanks for your time.

Welcome to the thread!

We could definitely use someone to take the initiative (and make the investment!) of offering assembled devices, and it sounds like you might have the background to do it. One big hurdle and expense would be testing and compliance for emissions, which I chose not to do.

I just sent you the zip file containing all of the information from both threads.

Howard,

Thanks, received the zip file. lots of good stuff in there.


All/anyone/everyone

Does anyone know if there are any patents filed anywhere for any transponder/decoder lap timing system?

Regards

MAC55

Google returns this: http://www.google.com/patents/US20120087421

The basic concept of how their transponders work has been around for at least 25 years and should be out of protection. But thanks to our completely dysfunctional patent system, "should" doesn't enter into it. They would definitely sue anybody selling a system compatible with theirs, and they'd probably sue anybody selling a non-compatible system that was even vaguely similar. With enough money, lawyers, and patience, you could almost certainly beat them. But then you're out a whole lot of time and money.

I'm not a lawyer or a patent expert. This is just my opinion based on watching the same damn thing happen all over the tech industry and factoring in AMB's litigious (and dickish) history.

Got everything ordered to build a decoder system. Expecting to receive everything by the end of December. Will post results

Is anyone actually using this system in an offroad track? if so? for how long? Any Issues? I'm looking into building one of these but rc-demon doesn't seem to be getting it to work at all...

I will be building mine in a few weeks. If you're not in a hurry and want to wait for results. I will be making 2 systems, we have 2 offroad tracks during summer, and we will use one system for indoor, during winter ( I live in Northern New-Brunswick, Canada )

I'll be eagerly waiting for your results :D
Please report back!
Thanks

Have you guys had any luck decoding the new RC4 units? The three wire ones?

I have not, but I believe others have. Hopefully they will respond to you.

I built myself a little automatic pit system with an Arduino. It works fine but you have to call each person to pit once per race. If I could id each car by transponder, people could pit on their own and the system could "remember" who did their one pit stop without the race director having to call them to pit. :nod: