A simple remote control for robotrain with a little display and two buttons. It can be used to send speed and direction commands to motor-control. It also displays the actual speed of the train.
Note: Wire colors do not match picture above!
This is an export from the Fritzing file in this directory.
128x64 px OLED displays come in many different configurations which all look very similar or even the same. Your display will most likely not work on the first try!
This Sketch uses the library U8g2 library by oliver because it supporty a wide variety of configurations of this display.
To learn more about your display, it recommend to watch this video.
You can select a different display by changing the following line right at the beginning of the sketch:
// OLED display:
U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, PIN_DISPLAY_SCL, PIN_DISPLAY_SDA, U8X8_PIN_NONE);This directory contains a file named config.template.h. Please create a copy of this file and re-name it config.h.
You need to configure your WiFi (ssid and secret) as well as MQTT broker (server and port) in config.h.
Note that you have to provide your WiFi secret in plaintext. This is a security risk as Arduino programs can be downloaded from the board. Therefore I recommend to use a separate WiFi for your robotrain setup.
The delays and timeouts for WiFi and MQTT usually don't need to be changed. If your infrastructure is particularily slow or instable, changing the values might help to fix issues.
If you use a different wiring, you can configure it in the pinning section.
The same applies to the MQTT topics. You should only change those if you use different topics in your whole robotrain setup.
This sketch uses the following standard libraries that come with the Arduino IDE:
- WiFi (1.2.7)
It also uses the following additional libraries that can be installed via Tools > Manage Libraries...:
- PubSubClient by Nick O'Leary (2.7.0)
- U8g2 library by oliver (2.27.6)
The version used and tested with this sketch is indicated in round brackets.
If you haven't used NodeMCU boards before, you need to install it via Tools > Board Manager first. The package name is esp8266 by ESP8266 Community.
Then select NodeMCU 1.0 (ESP-12E Module) in the Tools menu and upload the sketch to your board.
This remote control can send nominal values to the remote control and display actual values received from the train.
You can increase the nominal speed in steps with the right button up to the max value. If max value is reached, clicking the button will not increase the speed further.
You can decrease the nominal speed in steps with the left button down to 0. If 0 is reached, clicking the down button again will change the nominal direction of the train.
Step width as well as min and max speed values can be configured in config.h. You should interpret SPEED_NOMINAL_MAX as "max speed in forward direction" and SPEED_NOMINAL_MIN as "max speed in reverse direction". As the scale is intended to represent precentage, MAX value should be 100, MIN value -100. If your train can't run the same speed in both directions, you can change one of the values accordingly. It is possible to use values above/below 100/-100, but the recommendation is to stick with 100/-100 for the direction the train can run faster.
Each click of a button will send a message for nominal speed and nominal direction each to the MQTT broker.
| no. | name | descripton |
|---|---|---|
| 1 | nominal speed caret | Indicates the currently selected nominal speed sent to the train. If the caret overlaps the actual speed bar or limiter indicator, it will be displayed with inverse colors. |
| 2 | limiter indicator | If SPEED_NOMINAL_MAX != abs(SPEED_NOMINAL_MIN), the limiter indicates the reduced maximum speed. |
| 3 | textual representation | This line indicates the currently selected nominal values in textual form. "REV" or "FWD" indicate the current direction followed by the numbers for current and maximum nominal speed. |
| 4 | actual speed bar | Indicates the actual speed received from the train. |