03. Train crossing (part 1) - St. Andrews Crossing

January 12, 2023

Hi,

St. Andrews Crossing

So, have you finished your course on Python coding, great!

Let's then get into business.

So I divided the train crossing in two parts.

This part is for the St. Andrews Crossing lights, the second part will be for the automated barrier.

# Train crossing (part 1) - St. Andrews Crossing

So I found some cool St. Andrews Crossing / crossing lights on some train websites (link at bottom of post) but I decided to make my own - home made crossing lights, by a fraction of the price. The result was actually pretty cool.


3mm LED lights

Material:

* 4x red 3mm LED lights - couple of €/$ in an electronic store

* 2x 1K ohm resistors - couple of €/$ in an electronic store

1K ohm Resistor

* soldering iron and solder - If your going to go into more electronics you might as well purchase a good one.

Standard soldering iron

* wire cutter - to cut LED and resistor

* black paint and a brush tool

Step 1 - Pick the LED lights and bend them like in Picture below. Use the soldering iron to sold the resistor in the negative (cathode) part of both LEDs (the negative part - smaller leg). Make two sets, one for each side of the crossing. Make sure that negative led don't touch positive leg as you bend them.

obs. 1Kohm resistor it's OK for both LED as we are connecting to a 5Vdc output from pyboard. In fact they won't be charging LED at the same time but toggling. You can use any resistor to your liking. Make sure you don't use a very low resistor ohm value so you don't burn your LEDs.

Step 2 - Cut some round card board with a 3mm hole to make the support part of LED and the bending cap. Paint all with black paint, except the front part of the LED. Glue the support and cap to the LED.

LED set full picture

* * *

testing...

You can test the lights with a simple 5Vdc from any old mobile phone charger running around. Strip the microUSB plug and use the wiring to connect to the LED legs.

Obs. You can use charger to latter power your pyboard project.

Red to the Anode (Vcc) and Black to the Cathode ( - ) like bellow:

MicroUSB side:

5 - connect to Resistor

1 - connect to the any of the other legs

* * *

Pyboard Software:

If you already have a Micropython board you can revert to Micro Python SW section on this blog to download and test your flashing LED software in your pyboard.

Connect LED lights to your pyboard as bellow.