Z70 Locomotive for OS-Railway - fully 3D-printable railway system! Arduino-controlled!

thingiverse

It seems like you've provided a detailed description of a DIY robotic locomotive project. I'll summarize the key points: 1. **Motor Board:** The motor board is a Dual TB6612FNG (1A) from Sparkfun.com, which was chosen for its compact size and ability to handle PWM or analog inputs. 2. **Source Code Description:** * The program uses a micro button switch to activate motion. * A potentiometer is used to set the speed of the locomotive. * When the button is pressed, a counter starts counting either control loop (preset to 1/10S). * Depending on how long the button is pressed, either forward or backward motion is initiated. * The motor PWM is increased with a pre-set acceleration value which can be adjusted in the code. * During motion, the speed knob can be turned to directly adjust speed. * If the button is pressed longer than the pre-set emergency stop counter value, the PWM will be cut off as soon as the control loop has counted to that value with the button pressed. 3. **Resistors for LED's:** * The resistors for the LED's are not specified in the schematic because different supply voltage and different LED's will require different values. * A method is described to find out what value to use without doing any calculations: * Take a potentiometer and connect two wires, one to the middle (output) and one to either of the sides. Measure with a multimeter and turn the knob so you have maximum resistance dialed in. * Wire up the LED's in series and measure the current. * Slowly turn the potentiometer knob (lowering the resistance) until the LED's shine bright enough, or around 20mA of current is reached. 4. **Alternative Powering LED's from Motor Board:** * The motor board can handle two motor outputs and only one is used for the motor. * The other output can be used for LED's by connecting them to the B01 and B02 pins on the motor board, and AIN1 and AIN2 pins on the Arduino. * If you want to be able to dim the lights, connect an extra PWM output from the Arduino to the PWMB-input on the motor board.