Code:

The code for the project can be downloaded from Github: https://github.com/DIY-Machines/Smart-Model-Steam-Train

The full written guide for programming the ESP is further down this page.

Painting the model

You'll need a just a few things to decorate the train as I did. If you're lucky enough to have an airbrush, great, but I didn't (as much as I wanted to treat myself to one) so I used spray cans and paints along with a small basic kids paint brush.

• Paint for decorating: https://geni.us/Vallejo-Steam 
• Grey primer: https://geni.us/Grey-primer 
• Gloss finishing coat: https://geni.us/Gloss-Protection-Spray

I decorated the each printed part of the train before assembly. This allowed for better coverage of sprays and paint.

Undercoat

To help disguise the original colour of the filament used for the printed parts I started with a base coat of 'Hycote Grey Primer'. Not only does this cover the parts original colour, but also provides better adhesion for the following layer of paints and slightly reduces the appearance of layer line artefacts from the printing process.

Follow the instructions on the can. Mine required shaking for a few minutes and then painting several thin layers with a side too side motion. To help me get at all the surfaces I used some blue tac to temporary fix the printed part to then of a glass bottle.

Decorative coat

I used a common cheap children's painting brush and some Vallejo acrylic model paints to add the colours. I found these to have excellent coverage quality and further helped to reduce the visibility of layer lines. I applied at least two coats of this allowing around 10 minutes to dry at room temperature between applications.

They also stock a range of 'liquid metal' paints which create a very smart and ey catching metallic metal effect. I opted for gold on one of my models and bronze on the second. Both really gave a fantastic feel of a highly cared for and polished steam engine.

Protective coat

To help protect the paint job from abrasion and dampness I finished the model with a few coats of clear gloss sealer. This is also gave everything a lovely sheen. If you wanted something less reflective then you can get selling sprays in matt and satin finishes as well.

Programming the ESP-32

There are several (easy to follow) steps required to be able to upload code to your ESP32-CAM board. Some of them you may be able to skip if you have already completed them before, for example, installing the Arduino IDE. The steps you need to follow are:

• Install Arduino IDE
• Install the ESP32 Board
• Connect your board to your PC
• Upload the projects code

Installing Arduino IDE

If you do not already have the Arduino IDE installed (software to help programs microcontrollers) you can freely download it from Arduino at: https://www.arduino.cc/en/software

I'm using their newer 2.0 version of their software in the screenshots below but the instructions are close to identical for both the new Arduino IDE 2.0 and the Original Arduino IDE. Just follow their simple installation instructions on their website..

Installing the ESP32 Board

The Board Manager within the Arduino IDE allows us to install additional Cores. A Core allows the software to add compatibility for additional microcontroller such as the ESP32-CAM we are using for our model steam train.

Before we can add the board core we require we need to let the Arduino IDE know where it can look to find the files we need. To do this go to 'File' > 'Preference (or on a Mac 'Arduino IDE' > 'Preferences')'. In the window that opens add the following into the 'Additional Board Managers URLs' field:

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

If you already find another URL in the box, just separate the two from one another with a comma. You can then press OK to save the changes.

To add the required cores, in the Arduino IDE, click on 'Tools' menu along the top followed by 'Board' and then 'Boards Manager'.

In the window which opens for the Boards Manager you will find a search box along the top. Search here for 'ESP32' and then install the software for 'ESP32 by Espressif Systems' (if it was not already installed).

Connect your board to your PC

To connect your ESP32-CAM to your PC you will use a USB connection. We use an 'FTDI' board (Future Technology Devices International ) to convert our USB signals to a signal our ESP32 microcontroller will understand. Your ESP32-CAM board should be able to 'piggy back' onto of the FTDI board like so:

This is then connected to your computer using a USB cable.

Upload the projects code

Now you can simply download the projects code from it's page on Github: https://github.com/DIY-Machines/Smart-Model-Steam-Train

Once your on the Github page, click 'Code' and then 'Download ZIP'.

Open the ZIP folder which you just downloaded and then open the SmartTrain.ino file in the Arduino IDE you prepared earlier. With your board connected to your PC with a USB cable via the FTDI programmer we can select the board type of 'AI Thinker ESP32-CAM' from the drop down near the top. Then press the upload button.