[Nonfractal]

Rick
Regarding your topic

"Both systems use dongles so it’s possible. What’s missing to complete 
the brief? Only one thing. A few lines of code. "

I don't see the reason for lap counting to be built I to the control systems at all.

With oxigen and Scorpius, would it not be better to completely abandon the use of the proprietary inbuilt lap counters and go for a third party lap counting system independent of both oxigen and scorpius?
Oxigen's lap counting "chrono" causes more problems at events than any other  component. 
I would not be sorry to see it cut out of the picture.

RC cars use systems that are independent of the rc and speed controllers.
Why not slot racing ?
AlanW

[ScorpiusWireless]

Hi Alan, 
   Thanks for chiming in. Grok says Trackmate Iridium transponders are 25x12mm and an entire system costs around $400. 
Others on the market $1-$4k.
Cheaper ones tend to be old school infrared. 
Could it be done? Yes. 
A top of the line set up will cost as Grok stated $1-$4k which is not cheap.
Considering Scorpius lap timing is robust there is no advantage here for Scorpius users. 
Certainly I’ll take a deeper look. 
Thanks mate.

[ScorpiusWireless]

Ok it can be done, the MyLaps system would be around $1000 USD for the reader, transponders 30x1mm $30each and powered from braid wires.
System can added anytime.
Would need to agreed upon by manufacturers. 
Only concern is cost and take up valuable space within the car, add weight and a bit of complexity.

On another note Scorpius Lane Brain could take a reading from the cars LED and send a hard wired message to PC rather than wireless, reducing air traffic and chip glitches due to BEMF. A universal code for car ID could be established if all agree and easy to implement.

[Kevan]

Now that RC transponders have been mentioned...(incidentally, they were invented for RC car use by AMB.it in the early 80's then adopted by 1:1 racing such as NASCAR and other series.  They were small plastic boxes that had to be recharged between heats and held in the RC car bodyshell by a body clip.  We used those for many years before they were updated by newer tech)
...how about another challenge, sensored brushless motor ESC/transponder all-in-one

[ScorpiusWireless]

I already thought about it. 
TI make one for about $1USD. Plus a few caps and resistors. $2 tops all up for components. Use existing voltage regulator. 
It would need to connect to the main 832 processor and the board possibly requiring another layer which would add cost.
The issue is the closeness of the two antennas, albeit one is is a high frequency range and the other a lower. Still they need some separation.


I explained the situation to Grok, stating if was an addition to an existing board using the Nordic processor. 
This is what Grok said:
(Grok still makes mistakes, mixes up Scalextric in Spain with Scalextric Uk, it even stated something the other day that contradicted Ohms law. So take that into account)

QUOTE 
Adding a transponder like the Texas Instruments models to your MPD board shouldn’t be too complex, but it depends on the specific transponder and how you want it to integrate with your existing setup. Most TI transponders, like RFID transponders or similar wireless modules, require a few key components: an antenna for communication, a minimal power supply circuit, and an interface to your Nordic NRF52832, typically via SPI or I2C for data exchange. For hardware, you’d need to add the transponder chip itself, say a TI RFID transponder like the RF430 series, plus a properly tuned antenna, which could be a PCB trace or external coil depending on range and frequency, usually around one hundred twenty-five kilohertz to thirteen point five six megahertz for RFID. You’ll also need a few passives—capacitors and resistors—for matching and filtering, as specified in the transponder’s datasheet. Power-wise, the NRF52832 can supply three volts or so, which most TI transponders can work with, so you likely won’t need a separate regulator unless your power budget is tight. Software-wise, you’d program the NRF52832 to communicate with the transponder over the chosen interface, handling data like tag reads or writes. TI provides libraries and sample code for this, which you can adapt. The catch is ensuring your board’s layout supports the antenna without interference from motor drives or other noisy components—keep the antenna away from those. If you share the specific transponder model you’re eyeing or the use case—like range or data rate—I can narrow it down further. Got a particular TI part in mind?

I then asked the impact on the existing RF system used in the main processor:

QUOTE
[b]Interference between a transponder’s antenna and the NRF52832’s two-point-four gigahertz Bluetooth radio is possible but manageable with careful design. The NRF52832 uses a high-frequency band, while most Texas Instruments transponders, like RFID ones, operate at low frequencies—typically one hundred twenty-five kilohertz or thirteen point five six megahertz. This frequency difference reduces the chance of direct interference, but you still need to watch out for physical layout issues. If the transponder’s antenna, say a loop or coil, is too close to the NRF52832’s antenna, you could get electromagnetic coupling or noise, especially if your motor drives are switching rapidly and generating EMI. To minimize this, place the transponder antenna as far as possible from the NRF52832’s antenna on the PCB, ideally on opposite ends or layers, and use ground planes or shielding to isolate them. Also, ensure the transponder’s antenna is properly tuned to its operating frequency to avoid spurious emissions. On the software side, you might need to coordinate the duty cycles so the transponder and Bluetooth radio don’t transmit simultaneously, though this is usually only an issue in high-throughput applications. If you’re unsure about the transponder type, something like TI’s RF430FRL152H, which is low-power and SPI-compatible, could work without taxing your board’s resources. Want me to dig into layout tips or a specific transponder’s specs?[/b]
So there you have it, it mentions 3cm. The MPDis 23.8mm long so the most we could keep the antennas seperate is around 20mm. 
You could use firmware to minimise interaction but the only real way to know would be to build one and try it. 
The only downside I can see is the cost of the reader. Home tracks wouldn’t use it. It would only really be for mixed brands events so perhaps not a big deal. It is also a cool way to get around the compatibility issues between brands at least for lap timing.
It would be in real time too.

[Kevan]

I meant to add digital to that...sensored brushless motor ESC/transponder/digital all-in-one

[ScorpiusWireless]

Yup that’s what I meant also.
The only divide would be the fact I’d need a brushless decoder and a brushed decoder. Putting them all in one would mean too big a decoder plus price would be prohibitive. Plus delay the original project. 
So 2 chips would be the preference. A transponder could be added especially to the brushless decoder if it ever goes ahead but lots to consider.

[Nonfractal]

Maybe, I didn't make my point clearly. 
If the proprietary lap counting were completely abandoned at an event, replaced by a separate transponder system, maybe multiple car-control systems could run concurrently on the same track? 

If oxigen and scorpius (and any other system) were ONLY controlling the cars and the lane changers, the whole thing would be simpler.

In oxigen, lap counting is weak.
Chrono is a weak point. Crashing Often.
Lap counting triggered by the in car hall sensor Is also a weak point, easily damaged causing counting errors and causing the carscto go into "pit lane mode" 

Alan

[ScorpiusWireless]

We’re exactly on the same page. My opening comment mentions 2 or more brands.
The main 2 points.
1. Scorpius and 02 run on straight DC. Carrera is coded DC. All three could run together with but I can’t see Carrera being a comp level system. But it could be done.
2. So straight DC would be the basis. Transponders the lap counting. The remaining obstacle that being lane changing. If you want just to change lanes with no added funky functions the Scalextric system where the LED flashes a coded signal from the cars LED. Varying the space ratio of on to off differentiates the IDs limited 1-6. That won’t be used here. Here we use the Scalextric protocol where the space ratio of on/off time is inverted to trigger a lane change. You could use any ID 1-6. Let’s pick 1. As long as the button on the controller is activated it will flash a lane change request. Unless Ive missed something I’m sure that’s doable, and the Scorpius MPD has a couple of spare IR LED drivers to use for Carrera or SSD protocols. Transponder data could go straight to the Scorpius RMS or any RMS using cables from reader to PC to avoid wireless issues.
3rd or 4th brands could be anyone from a cottage set up guys to a bigger manufacturer. The more the merrier.

[gref]

following with interest