I do know Marklin M track solenoids can be operated on DC. I just felt like driving them with AC. This was the first successful trial.

Control bugs worked out today which includes a reset button for setting the switches and signals into the "all trains parked" positions.

Today the AC to DC optoisolator circuit bugs were worked between the Marklin ~17 VAC input and the Arduino analog inputs. I chose to use the analog inputs to maximize the digital in/out pins for output control. Now the system is capable of feedback for knowing where the trains are.

If anyone wants to see the Arduino code or the Processing code let me know and I'll post it. I'm sure there are skilled programmers out there who could greatly streamline my patchwork of simple code routines.

Coded a few sequential trains. Several more to go. Soon it will be time to continue on level two.

so you are controlling the turnouts, but are the trains being controlled digitally or are you switching track current on and off using the Duo?

For the turnouts are you using MOSFETs or simple relays?

I've been replacing the homemade track sensors with the old style contact tracks. The old style contact track is a much better solution.

Here are photos of the sensor circuit, data, and parts. Take a look. It should describe the circuit pretty well. Let me know if you have any questions. I'll try to answer as best I can.







Regards,

Gary

I found that a 10 uF capacitors works better than 0.1 uF. It provides better debounce (for lack of a better term) due to less sensitivity. The circuit works if the capacitor is connected across pins 5 and 6 or across pins 5 and 8. It was easier to build the homemade circuit board using pins 5 and 6.

It is possible to invert the logic in code rather than a chip yes, but the output of the optoisolator will not drive the input of the Arduino. I needed a chip to drive the input of the Arduino. A hex inverter has the most number of logic gates in one chip.

The old style contact tract is shown in the schematic as a switch. The contact track does complete the AC portion of the circuit when the wheels and axle roll over the contact track, making a connection between the insulated rail and the non-insulated rail. I do generally think of the M track metal base as a "ground bus" even though its AC.

Edited at: by user 11 August 2019 07:39:48(UTC)  | Reason: Not specified

Thanks, I'll try pinMode( input_pin, INPUT_PULLUP) on the next project.

Gary

Hello Gary
I am interested in the way you drive the turnouts. I am now in my 3rd month of exploring the web how to switch the turnouts with an arduino uno. But I am on a wrong end.

I was able to switch the turnouts :

1. semi digital by means of ir gates through an opto coupler to be switched by a TIP120, 12 volt DC and through a diode and 2200uF cap to rectify the Ac to ACDC current

2. ir gates to be switched by arduino and a bistable 5 volts dc relay for the feedback of the tunrout, with the proper sketch to switch the 2 IR gates and read the the signal

3. The last fase I have built were various switches with different opto couplers
7 volt input with button to switch optocoupler ( dc isolated from rest of the circuit) to an array 2803 darlington to be switched by the optocoupler output and the output of the 2803 to the blue connections of the Marklin turnout. This works fine, however!!!

I am not able to write the correct lines for the sketch for arduino in which the arduino receives the input signal of the IR gates and then Output to switch the turnouts. Is it possible for you to send me the electronic scheme/layout of the circuit you have used and hopefully you will include the Arduino sketch.

I can also send you some circuits which I use. I tried to include some sketches but this site does not accept INO and TinyCad enclosures
Thanx in advance
Henry

Using a triac and opto isolator seems to be an expensive route (but certainly robust looking)

Tiono (from this forum) kindly send me his diagram for switching turnouts...



His design uses 6 resistors, two transistors and two diodes for each turnout.

I can get 8 outputs from an ESP8266 essentially creating a K83 using 4 copies of his diagram, but I have not yet tried his circuit.

yes, he get confirmation that it has triggered. I would not bother as it is only on the electrical side, one still does not know that the mechanism threw...

so in fact those 4 resistors are not needed....

Here is the AC TRIAC driver circuit schematic I am using.

Unfortunately I am unable to see the photo of the schematic imbedded in the file.

I open it with Word13 and I don't see the picture, only text
regards

Good afternoon

As I already indicated my knowledge of programming with ARDUINo is nill.
I have made a sketch for switching a MArklin M electric turnout (double coils AC) by means of 2 infrared gates, 1 bistable HONGFA relay for indication of turnout position, and/or separate leds (on a breadboard) . I tried to use state change lines as you will see in the enclosed sketch.

When all is coupled, the IR gate1 wil switch the turnout1 and when passing ir gate 2 will switch back . After that nothong happens further.

Can you help with the missing parts INFRARED GATES switching Marklin Turnouts 19 jan 2020.pdf (46kb) downloaded 74 time(s).

Regards Henry
The Netherlands

I didn't go through the logic of your code but I did notice the IF statement brackets were out of alignment. I realigned the IF statement brackets and got the code to compile. See if this gets you anywhere. If not I would have to build a similar type test circuit.

/*Forum name Holz1
Author: Henry The Netherlands 19th January 2020
INFRARED GATES are switching Marklin M electric TURNOUTS (AC Double COIL) by means of a module based on Opto Couplers and Darlington NPN transistor. A separate
HONGFA //BiStable Relay 12V-DC, LEDs (RED and Green) can be turned on for indication of the turnout position.

The SKETCH is as follows:
*/

//Declaration of the 2 INFRARED Sensor Gates
const int IRS1 = 6; // de (INFRARED Gate) INFRAROOD sluis 1(IRS1) is op pin 6 PWM van de Arduino aangesloten
const int IRS2 = 7; // de (INFRARED Gate) INFRAROOD sluis 2 (IRS2)is op pin 7 PWM van de Arduino aangesloten

// Declaration of the IR sensor states
int IRsensorState1 = 0; // de huidige (present state) status van IRS 1 wordt bewaard
int IRsensorState2 = 0; //de huidige (present state)status van IRS 2 wordt bewaard

// Declaration of the LAST state of the LAST IR states
int lastSensorState1 = 0; // de (previous state) vorige status van de IRSluis 1
int lastSensorState2 = 0; // de (previous state) vorige status van de IRSluis 2

// Declaration of the HONGFA BI-STABLE relay for LED indication of turnout position: LED RED (BENDING) and LED GREEN (STRAIGHT)
#define relais1 2 // PWM pin 2 van de Arduino wordt op het relais pole 6 aangesloten
#define relais2 3 // PWM pin 3 van de Arduino wordt op het relais pole 7 aangesloten

// Separate LEDs can be installed on pin 11 (RED) en 12 (GREEN)
// The Marklin Turnouts are declared
#define Wissel_1 8 //Digitale pin 8 wordt op Märklin Wissel 1 aangesloten en is OUTPUT
#define Wissel_2 9 //Digitale pin 9 wordt op Märklin Wissel 2 aangesloten en is OUTPUT
#define RELAY_TIME_MS 150 // The time to switch is milliseconds for switching the
//MARKLIN Double AC COIL

void setup() {
// The IR gates are declared as INPUT /dit zijn de Infrarood lichtsluizen
pinMode(IRS1, INPUT); // IR sluis 1 is op input PWM pin 6 aangesloten
pinMode(IRS2, INPUT); // IR sluis 2 is op input PWM pin 7 aangesloten

// The MÄRKLIN TURNOUTS are declared as OUTPUT
pinMode(Wissel_1, OUTPUT); // Pin 8 schakelt Märklin Wissel 1 rechtdoor
pinMode(Wissel_2, OUTPUT); // Pin 9 schakelt Märklin Wissel 2 afbuigend

// The HONGFA relay is declared as OUTPUT and switches Green LED or RED LED /dit is bistabliele relais voor wisselstand terugmelding
pinMode(relais1, OUTPUT); // Wanneer IRS1 wordt gepasseerd, schakelt het relais1 op rood
pinMode(relais2, OUTPUT); // Wanneer IRS2 wordt gepasseerd, schakelt het relais2 op blauw
}

void loop() {

// The signal of the IR Sensors are read / het signaal van de IR sluizen wordt gelezen
int readsen1 = digitalRead (IRS1);
int readsen2 = digitalRead (IRS2);
IRsensorState1 = digitalRead (IRS1); // The IR sensor states are read for recovery and
//comparison of the last IR states
IRsensorState2 = digitalRead (IRS2);
if (readsen1 == HIGH && readsen2 == LOW) { // If IRS1 is HIGH and the IR Gate 2 is NOT
if (IRsensorState1 != lastSensorState1) { // ????????
digitalWrite(Wissel_1, HIGH); //Turnout 1 is switched / De Märklin wissel 1 schakelt naar //afbuigen
delay(RELAY_TIME_MS);
}
// save SensorState for next comparison: //???????????

lastSensorState1 = IRsensorState1; // ????????


// LED RED (BENDING) and LED GREEN (STRAIGHT)/ deze leds kunnen via pin 11 en 12 //apart worden aangesloten
digitalWrite(11, HIGH); // The Turnout position leds are switched through the HONGFA relay
digitalWrite(12, LOW); //digitalWrite zet led aan en brandt, analogWrite blijft led uit

// When The Turnout 1 is switched the HONGFA relay will switch the RED LED light to Bending/het relais ontvangt signaal en wordt geschakeld
digitalWrite(relais1, HIGH);
// The TURNOUT will be switch to BENDING/ De Märklin wissel 1 wordt geschakeld
digitalWrite(Wissel_1, HIGH); //Turnout 1 is switched De Märklin wissel 1 schakelt naar //afbuigen
delay(RELAY_TIME_MS);
digitalWrite(relais2, LOW); //????????
delay(RELAY_TIME_MS);
}


if (readsen2 == HIGH && readsen1 == LOW ) {
if (IRsensorState2 != lastSensorState2) {
digitalWrite(Wissel_2, HIGH); //The TURNOUT 2 is switched when the IRS2 is passed/ De
//Märklin wissel 2 schakelt naar afbuigen
delay(RELAY_TIME_MS);
}

// save SensorState for next comparison: lastSensorState2 = IRsensorState2; //???????????
// LED RED (BENDING) and LED GREEN (STRAIGHT)/deze leds kunnen via pin 11 en 12
//apart worden aangesloten
digitalWrite(11, LOW); // de IR sluis niet wordt gepasseerd brandt LED baanvak vrij
digitalWrite(12, HIGH); // de bezet melding is uit
digitalWrite(relais2, HIGH); // The Turnout position leds are switched through the HONGFA

//relay/ het relais schakelt het baanvak vrij in: de groene led brandt
delay(RELAY_TIME_MS);
digitalWrite(Wissel_2, HIGH); // The Turnout is switched to STRAIGHT /De Märklin wissel

//2 schakelt naar rechtdoor
delay(RELAY_TIME_MS);
digitalWrite(Wissel_1, LOW);
delay(RELAY_TIME_MS);
digitalWrite(relais1, LOW); // The HONGFA relay is switched : GREEN LED is on! /het relais
//schakelt de bezetmelding uit: de rode led is uit
}
}

Hi guys,

I'm new here although I've been a Marklin advocate for more than 50 years. I'm strictly old school, M-track, analog, AC. I live in China and so obtaining stuff is either very expensive or not feasible due to shipping costs. I have no signals or connect tracks and being that most of the worlds electronic components are made here, they are very very cheap to buy, I decided to just make my own.

I was interested in arduino and after reading this thread, I ordered a nano to arrive in a couple of days. Luckily, I teach C/C++ in a local university. I decided to try using IR for train sensing and wondered how you use the sensors on your layouts. I did some experimenting using some 3mm LEDs as an esthetic test and it came out pretty good. I used the existing screw hole in the M-track and then drilled it out to 3.2mm. I added an additional hole on the other side of the center rail. For testing purposes, I used 3mm green LEDs just to see how it looked. My IRs will also be arriving shortly. I checked for clearance, whether the shoe would be hindered, how much they stuck out of the track, etc. I added a piece of electrical tape to the bottom of the track to help with the reflectivity of the underside of the M-track. Looks pretty good to me. I plan on gluing a piece of foil on the bottom of the locomotive either in the front or the back to trigger the IRs.

I plan to try out Holz's code as it looks pretty solid and I'm interested in expanding it to include turnout controls.

What do you guys think?

Thanks for the feedback
Michael in Tianjin, China.

Thanks Jean!

This is another option for cheap contacts. I smashed flat the end of a small diameter brass rod. This has actually worked surprisingly successfully for over a year now.

Antonio Martinez of this forum has a nice solution to adding a sensor in hidden areas.

I used it very successfully on my old layout: https://cabin-layout.mixmox.com/2004/02/Martinez-type-contact.html (That link also shows an earlier idea I had, which I abandoned.)



One can take the output of such a switch and connect it to a pin of the Arduino type processor.

I have some updates with pics for my IR M-Track.

I adjusted the sensitivity on the IR sensors using resistors. Some said use 10k Ohms, but that was too much. I had to touch a piece of foil against the LEDs to make them detect. So I tried 3k Ohm resistors. That triggered around 4cm with my hand. I found that 4.7k Ohm resistors worked perfectly with a piece of foil taped to the underside of the locomotive before or after the shoe and rolling stock did not trigger the IR sensor.

Here are some pics of the finished track sections.

HI Gary,

Just started exploring the options with Arduino and model trains. In the past I used MOC3020/3040 optocouplers. They have a triac inside. I don't think you can eliminate additional triacs because of current limitations but maybe the schematic can be simplified?

I haven't read all your posts but I would love to combine the Arduino and the Märklin digital system. Any thoughts on that for signaling and switching?

Regards,

Paul

Hi Guys, well I've been tinkering with this idea for years and given away the switching track as it was not 100% reliable nor the newer version with C-track, I use K-track and noticed the last post made holes into the M-track, one could say I use a more simpler version and have come up with opto couplers which are placed between the sleepers and are triggered by the slider, but you only have a 1 way detection, which means your trains have to run always in one direction., my option could be placed by making a hole close to the middle stud track and so long the slider picks up the infra red signal you shouldn't have any problems with it. the opto coupler I'm using have a range of 8mm from the same level as the sleepers., it doesn't pick up any axles.

John