[ScorpiusWireless]

Here it is. 
The SCX Solenoid driver and pins has been replaced by a Digital to Analogue Converter chip or DAC.
Our OLED driver connects to a 0.49" OLED screen to select channels.
We have utilised the two Photo Transistor analogue input pins to connect a set switch.
As usual the MPD is used as the mother board.
The board is powered off the 5V supply from the CU.
The DAC chip connects to the CU via the RJ12 telephone plug.
The Scorpius Controller to MPD data is complete.
And work is underway in the next few weeks to implement Carrera Controller protocols to the CU.
So as you can see the MPD really is a Multi Protocol Decoder capable of almost anything. 
In fact the Controller, USB Dongle and MPD can do every single function required for any brand. Very cool indeed.
The MPD boasts digital in/outs and now Analogue in/outs. 
Along with the TX/RX in/outs added and the OLED driver this is going to be a killer product.
And all this in 22.00x13.3mm.
Thankyou Johnny you are a legend!

   

Rick

[ScorpiusWireless]

The CU can also take  PWM data via ports and it’s also an option. Just trying to work out the most practical path.

[ScorpiusWireless]

Decision made, we're proceeding with PWM (digital code) instead of analogue. More firmware work but no DAC chip required.
This means if all is good we would have nailed the MPD hardware on the second manufactured version, which arrives in 4 weeks, although it will need to be thoroughly tested for data loss due to rail noise. Its still possible a minor hardware change may be required.
It also means we are one step closer to production once we test Carrera protocols, BEMF detection and current limiting. 

[ScorpiusWireless]

   

Here’s a mock up of what the Scorpius Carrera dongle will look like. A 6 wire RJ12 plug and wire is cut and soldered to MPD. 4 wires go to our 4 pin digital port and 2 wires vampire 5V off the Carrera Control Unit. 
The trade off with utilising the digital comms option over the analogue protocol is that we lose our OLED driver port. But we have a work around for that.

There is 2 uses for this dongle.
1. Nitrous system. Controller controls car direct but also sends controller data to the CU to maintain compatibility in regard to apps and ti get that important lane change signal to the rails via the CU. 
2. Use Scorpius controller only to connect wirelessly to the Carrera CU. 
The firmware for most of it is available from the Scorpius car decoder protocol firmware already complete. So for this product we need to reverse the Carrera controller code and send it to the 4 pin digital port. There is some information available online. Again it means working with the dreaded Manchester code. 
   

[ScorpiusWireless]

Ok here’s a serious mock up.

What is it? It’s a dongle that receives Scorpius throttle data and turns it into Carrera throttle data and delivers it to a RJ12 telephone plug that connects to the Carrera CU.

We now we have not just one but two 12C data ports. This negates the need of a seperate DAC chip as mentioned in previous posts here.

The blue and white wire are 12V power from the CU that powers the MPD. Phew no battery required.
The pic is based on the upcoming MPD V5 prototype coming in March with two 12C data ports not just one.
It will come with pins specifically for a reset switch pcb and a pcb mounted micro (momentary) switch.
So here I’ve replaced the Carrera reset switch with an off the shelf momentary switch connected to the 2 pins.
The OLED will be held in place by a 3D printed surround. It will be powered off the MPD.
The RJ12 plug is re-soldered to the MPD as shown.
At this stage I’m using a Carrera Dongle casing as it has a smart matching (to the app connect box) enclosure with the reset hole and screen cut out, labelling, as well as the RJ12 plug with a nice shroud where it leaves the enclosure. 
As you can see the MPDs small size makes for an easy install and everything fits nicely with room to spare.
I could also re-program an existing Carrera dongle. But we like everything hardware wise to be proprietary. It’s a possibility though and something to consider. 

Here we will simply use the proposed MPD V5 as is and only a firmware change is required.

That firmware upgrade won’t be easy. The good news is its only simple throttle signal and a LC switch signal.

The MPD “Digital wireless slot car Arduinos” adaptability and flexible interface make it so much easier to turn almost any conceivable idea into reality.