Model Railway Automatic Signal Control Using an Arduino: The Director's Cut

[@medwaymodelrailway7129]

Enjoyed the latest video and liked thanks DD.

[@parttimespotter2027]

Another great video. Can I ask how would you make the signal have a route indicators (feathers) that once a point is changed to head to a branch line the indicators show? I will be having a mainline set of points and just before it there will be a signal with a Route indicator. Once the point changes is shows the indicators.

[@ipcress1066]

It would certainly be possible but you'd just have to logic out the sequence in the program, unfortunately I'm not a programmer and this was cobbled together from what I learned from other people but if I can work it out anyone can!

[@geoffmarshall5036]

Paul I have been following your videos but now you have written out the override switches how are you changing from green to red on a junction?

[@ipcress1066]

Hello Geoff, thanks for the comment, sorry to say this was a bit of an experiment to see if I could drive four signals off one Arduino - it worked but the price paid was nicking the pins I previously used for the override switch so in this version the override is not available

[@geoffmarshall5036]

@@ipcress1066 ok that's understandable. I am not a programmer. It would be good if you could use the two spare pins to have one or two override switches. You could use a pair at two junctions. I like what you have done so far.

[@ipcress1066]

@@geoffmarshall5036 Food for thought Geoff, I'm not a programmer either and unfortunately forget most of what I did after a few months!

[@nonnymouse113]

Hi, many thanks for video , directions and tips. A quick question, I would like to extend the number of blocks to six. I assume that I am looking at a mega to increase the number of pins ? I understand that a pin will feed a led safely at about 20ma, What concerns me is the return common feed to the ground / negative pin. With 6 LEDs plus overlap of LEDs displaying, am I approaching the max current the ground pin will take ? I would like to avoid real smoke effects from the building which hides the mega. 😊 Thanks for your advice.

[@ipcress1066]

Yes I think what you're suggesting makes sense, according to the blurb on my Arduino Mega, it has 54 digital pins and 16 analogue pins so plenty of pins to play with. Regarding the number of LEDs connected to the ground - I don't think that will be an issue but worth experimenting with, firstly you have more than one ground pin on the Arduino so not all LEDs need to go back to the same ground pin and also I've suggesting using a 220 ohm resistor for each LED whereas you could try using a higher resistor - say 1,000 ohm which may make the LED slightly less bright but would cut down considerably on the current draw. Good luck!

[@nonnymouse113]

Many thanks for your reply I will let you know how I get on, but it may be a while. Just a word of caution to others that may have purchased 3 aspect signal heads offered on Amazon. The red, amber and green LEDs have quite different resistance values to get them to be the same brightness. The one resistor in the common return works, but the LEDs glow unevenly. Looking forward to modelling some signals. Rgds

[@ipcress1066]

@@nonnymouse113 Let me know how it goes, good point re the differing light levels of the LEDs.