Now that we have the OLED screen working (see previous video) we can do something fun with it for an HO model railway: a station platform train departure display, with an analog clock that really works. The 128×32 pixel display is just a little bit on the tall side for HO scale, but it doesn’t […]
We’re going to add a 128×32 I2C (4 pins) OLED to the distance measurement unit of the previous video to show the distance measured plus a bar graph. An Arduino Nano will be used this time, mounted on a breadboard. Together with the ultrasonic unit, the OLED and a 5V USB battery pack we have […]
The HC-SR04 is a nice little less than $1,- device that can be used to measure distance. It contains a loudspeaker and a microphone. When we send a pulse to its trig input, it will output an ultrasonic (40kHz) sound burst. It then measures the time it takes for the echo to return. We can […]
Some applications may need a stronger stepper motor, one that can deliver more torque. The picture shows a NEMA 17 stepper. It’s a form factor (it means the size is 1.7 x 1.7 inch) in which a range of motors with different specifications is available. They are widely used in (DIY) 3D printers and NC […]
The turntable application of video 35 expects to first run the ‘find zero’ routine after startup in order to have a reference position from where step counting starts. Suppose after every move we could store our current position in non volatile memory? At startup we can now read the stored position out of memory and […]
With the ingredients of previous two videos, find zero and rotate an exact amount of steps, we’re able to control a turn table that has multiple stop positions. We need to find out how many steps it takes, counting from the zero point, to reach every position. We’ll use a separate ‘Tuning’ sketch for this. […]
With the code of the previous video 33 we are able to ‘zero’ the stepper motor. From that point on we can position the motor by counting up or down an exact number of steps. This way we can accurately position, say, a turn table or an elevator, or anything we like. For most applications […]
A stepper motor does not know where it is after power up. If we want to use a stepper for accurate positioning, we first have to define its ‘zero’ point. This can be done by slowly rotating the motor until a sensor or a micro switch is activated. In this video we will add such […]
Now that we have our stepper motor running we can add some extra features, like: change direction change speed rotate an exact amount of steps for accurate positioning Read on below the video … To change direction and to also show a direction indicator LED, a function is created. There’s no real need to […]
With some applications it can be useful to use a stepper motor in stead of a servo. For instance when a continuous rotation is required to rotate, say, a wind mill model. Also with applications like a turn table, a linear shift table or an elevator, a stepper motor can be of great help … […]
