# Update to version 2.0.5 beta

Here it is – the next release – packed with new features and functionalities. The biggest is surely the all new Windows client (with its final name) miniEngine Studio!

The new miniEngine Studio can be found on GitHub: https://github.com/airiclenz/miniEngineStudio

The miniEngine software is also on GitHub: https://github.com/airiclenz/miniEngine2

Here is a list of all major updates and changes to the system:

• Added minEngine functions for the the minEngine Studio software
• Added new “Keyframes Mode” which is dedicated to (currently) only work together with the miniEngine Studio
• Added a function that updates settings to the new version during a software update (no configuration gets lost any longer)
• Improved dashboards to show only relevant data
• Optimized system modes and run styles for easier use
• Fixed a bug where the motor was not moving when motor sleep was enabled
• Fixed a bug that not saved the keep powered status.

# Software

The new Windows client has no documentation yet but should be pretty self explanatory as all button have a tooltip to guide you as much as possible. I also tried to make the user interface as clean and straight-forward as possible. If anyone of you still is not able to figure out how it works, please contact me via the forum. I will help you as good as I can to make it work together with your miniEngine!

If you have any suggestions or find bugs, please let me know. This is the very first release and there is surely lots of space for improvements!

…but mainly I just hope it is of any use for you guys!

Here are some limitations to the functionality which I am aware of:

• The defined curves can not yet be stored on the miniEngine. After a reboot everything is gone and needs to be sent to the miniEngine again (this will surely some later).
• The communication between the Studio and and miniEngine might not work 100% in any case. If something is not working, try pressing the button again.
• The system is not yet “water-proof” and might have some unexpected behavior. I highly recommend using it with care, common sense and limit switches to not destroy your hardware.
• It does not work together with the miniEngine v1.

# Documentation

I also added a big portion to the documentation which should explains the system-assembly in much more detail.

Have fun with the new stuff!

Cheers,

Airic

# path Designer

Hello everyone,

I want to let you know what the current status fo the project is and on what I am working on. So let’s get started…

## path Designer

The major development that is ongoing right now is a Windows based client software for editing and testing Bézier-based curves – in other words: you’ll have full control over all axes and thus will be able to define when your motors should be where. The software will connect to your miniEngine via the USB port. The curve / graph editor is basically done and it is already possible to create, save and load setups. Even the basic communication with the Arduino is working.

Here is a screenshot of the client in its current development state:

In the screenshot above you can see a setup with 2 axes (the second axis is the gray one in the background). The currently selected axis is using just 2 curve-segments (see below for an explanation what a curve-segment is). You can fill up your miniEngine with setups up to 25 curve-segments in total. This means that all your axes can together use 25 curve-segments. And here is a little graphic that shows what a curve-segment actually is (for the ones that want to know it in more detail – one curve-segment is one quadric Bézier curve):

Here is another screenshot showing that a curve does not need to be curved. The 2 last curve-segments are simply flattened to a linear segments (there is a button for doing that)

The client supports selecting multiple points and moving them all together as well as numeric point placement for very precise setups where every mm / ms counts.

The connection to the miniEngine will be initialized by simply choosing its COM-port:

The next steps will be to finalize the communication part of the software so that the the paths can be send to the miniEngine and the program can be started.

The software will be released as open Source under the GPL license. It is being developed in .NET Visual Basic. Please contact me if you want to port it to Mac or Linux (I simply don’t have the time to take care of the miniEngine as well as 3 different  computer-clients thanks to the need to sleep regularly)

## Documentation

The other place where things are happening is the documentation. I received some valuable feedback regarding the assembly of the BED-board. The next release will also contain some additional details about how to assemble the BED-board. There will also be explanations about different variants for connecting the Big EasyDrivers to the BED board and for connecting the BED board to the main Board of the miniEngine.

I am looking forward to the next release and hope you too!

Have fun!
Airic

# Update to version 2.0.4 beta

Hello everyone,

the new version is out and we are now in the Beta state. Here are the changes:

• Added the external trigger input system for starting, stopping and shooting the camera. This will be extended in the future with additional triggers.
• Added a Dashboard that is displayed when the miniEngine is running. This will make it clearer to recognize if the system is running or not.
• Added a messaging system. This allows messages to the user so that the system can tell what it is actually doing.
• Added a new system font. Now there are 3 choices for the ones that want to tweak their user interface for optimal readability.

The biggest and most versatile new feature is the trigger system. This allows the execution of core commands with external signals. Right now there are 3 functions implemented:

• Start the engine
• Stop the engine
• Trigger the camera

This means that you can now start multiple miniEngines simultaneously with one signal. You can also start / stop the miniEngine or trigger the camera on certain events  which could come from anywhere (‘want to play with a light sensor?). This is the current menu for the trigger setup:

The easies way to implement this new feature is this:

Please keep in mind that the trigger inputs are directly connected to the Arduino processor! This means you need to keep your signals between 0V and 3.3V – otherwise you might destroy your Arduino! If you use the above circuit and the trigger type “Falling”, it works without any external voltages and just a simple switch. In this case you can ignore the red text above.

Triggers are only active if the miniEngine was started by pressing the “Start” key. when you defined a “Start” trigger, the system will wait until it actually starts until the trigger signal arrived.

The next big new thing is the Dashboard. This is what you now see when the engine is running:

Here is the new font…

…and here the new message system in action:

I hope you like the new features and also that they allow more versatile setups and thus to boost your creativity.

Have fun and post some of your thoughts in the forum!
Airic

## Motor calibration

### Quote

Here is a little manual describing how to find the correct motor calibration value for your setup – the mathematical and most precise way. This can now also be found in the documentation:

The miniEngine 2 offers the possibility to calibrate the motors you are using. This calibration takes the motor and its specifications itself as well as the rig it is driving into account. This chapter is aiming at helping you finding the correct calibration value for your motor(s). The calibration values needed, should be given with the following units:

• steps per centimeter for linear movements
• steps per degree for radial movements

As stepper motors come in a variety of form factors and specifications we need to add the most important of these specs to our calibrations. This is the degrees been moved by one full motor step. The most common one is 1.8°. This means that such a motor needs 200 full steps to do one full revelation:

$\frac{360^{\circ}}{1.8^{\circ}} = 200$

Because we are using multi-stepping to achieve a finer resolution, we need to multiply this full-step-value with the amount of sub-steps done. In this example we are using 1/16th stepping (which is the default for the recommended Big Easydriver):

$200{\times}16 = 3200$

..or if you prefer the full version

$\frac{200}{(\frac{1}{16})} = 3200$

Ok – so we need 3200 steps to do a full revelation with the stepper motor in micro- stepping-mode. Now let‘s add the rig that this motor is driving to the calculation. For now we are assuming we are driving a toothed belt with the stepper. The gearwheel has a circumference of 3.5cm. This means that 1 stepper revelation moves the belt 3.5cm. Here is how we get how much steps are needed for 1cm – which is also our final calibration value:

$\frac{1cm}{3.5cm}\times{3200}=914.29$

Now we can enter 914.29 steps / cm as the calibration value into the system.

If we had a motor that would do a radial move, the calibration-calculation would just differ in the last step. Assuming you are not using the motor to rotate your axis 1:1 but with a reduction of 1:4 (four revelations of the motor rotate the axis one time) , the final calculation-step would look like this:

$4\times\frac{3200}{360}=35.56$

The final calibration value for the radial setup is 35.56 steps / degree.

I hope someone finds this useful.

Have fun!
Airic

# Software update to 2.0.3

Thank you all for submitting feedback and bugs! This allowed me to improve the software and here it is: alpha version 2.0.3! This release fixes some bugs and even adds some new stuff. I highly recommend updating to this release (Don’t forget to update the libraries too)! These are the changes:

Documentation
•  updated the documentation (added small system-user-manual)
Software
•  fixed a bug which started moves from the wrong position if not moved to home before
• fixed a bug that moved the motor in the wrong direction when using the function “Move home (all)”
• fixed a bug which caused the motor direction to change sporadically during motor jogging
• added a new menu font and a font-option to the settings
• Minor user interface changes
• added all needed libraries into the repository

The biggest change, which you will see immediately, is the new font. I thought it might be nice to have a more readable and clear option. There is a new option for choosing the font so that you can go back to the old one if you like:

I also started working on a Windows client for creating keyframe-based moves. This is in the very early stages but I hope to be able to release it before the summer. Main focus will be defining the bezier-curve based moves and then either save them as a files or directly submit the data to the USB-connected miniEngine.

…and as always – Have fun!
Airic

# miniE v2 release

I worked hard the last couple of days to get everything together and write an initial documentation. Now I am done and just released the miniEngine v2 to the public, to you. It is now available in the shop:

shop.airiclenz.com

..and all required files are committed to GitHub:

github.com/airiclenz/miniEngine2

The ones of you that have any questions, please post them in the forum. I am happy to answer them there.

Cheers,
Airic

# miniE2 boards are going online soon!

Hello everyone,

I just ordered the first batch of shield PCBs for the shop. They will be blue and available as soon as they arrived. I’ll also order some needed parts so that I can offer sets for those of you that want to start quicker.

In the meantime I will continue working on the software. The first version which will be released will have motor control for 2 motors with the new Bézier-based-algorithms. Manual motor placement, higher motor speeds, all measurements in seconds and cm (no more conversions from steps to cm out in the field) and the better user interface are just some of the benefits which will be available in the first software release.

This first version will not be finished but be the first step to the system which I designed to be as capable as possible incl. daisy-chaining, video moves, external inputs and so on.

I am looking forward to getting it into your hands!

Cheers,
Airic

# miniE v2 update 4.1

Hello everyone,

this is just a quick update on the Bezier-motor-control engine. I worked the last days pretty much all of my free time on the new “core” system and can say that it is more or less done. I now can define moves based one Bézier curves – or in other words by defining 4 points (2-dimensional: time; position) per curve. The engine is then processing the data to a list of linear segments (based on linear functions). So every curve becomes 200 linear segments. To get a smooth move, I developed an algorithm, that uses a finer granularity where the curve bends the most. In the picture below you can see the segmentation (in this case 100 segments):

Every motor-movement in the next version will be based on this new methodology as it allows detailed planning of the motors position in time. I even allows to get information about the speed of the motors at any time. On top of that is the motor movement much smoother as it was with the old delay-based engine. It also allows much greater speeds. I was able to move my dolly along my 100 cm (4 foot) track (this one) in 6 seconds with nice speed-ramping on both sides.

Because the DUE is fast enough and the motor position calculation is based on an easy linear function, there should be plenty of processing power for doing all this for 2 motors simultaneously. Right now there are approx. 0.05 motors steps done per processing loop. This means that the DUE only needs to step the motor every 20 processing loops. [Edit: Running 2 different curves with 2 motors simultaneously is tested and working perfectly.]

The only drawback is that this new control-methodology is making extensive use of the 96kb RAM that that the Arduino DUE has to offer. One of the curves with its 200 linear sub-segments is taking 2400 bytes of RAM. That means that in theory 40 of these curves can be stored in the DUE’s memory. Because the systems itself needs some of the memory too, lets say that 20-25 curves can be stored. I think that this is a good amount to design some pretty complex video-moves. Here is another example of how such a move can look like:

It consists of 3 curves and here is the actual source-code to define such a move by hand:

// x coordinate = time in ms
// y coordinate = motor position in cm
curve[0].p0 = Point( 0, 0);
curve[0].p1 = Point( 6000, 0);
curve[0].p2 = Point( 10000, 50);
curve[0].p3 = Point( 20000, 50);

curve[1].p0 = Point( 20000, 50);
curve[1].p1 = Point( 30000, 50);
curve[1].p2 = Point( 31000, 35);
curve[1].p3 = Point( 40000, 35);

curve[2].p0 = Point( 40000, 35);
curve[2].p1 = Point( 51000, 35);
curve[2].p2 = Point( 51000, 100);
curve[2].p3 = Point( 70000, 100);


The cool thing is that I can read the motor position for any time I want. This will end up in a feature to kind of fast preview the programmed move – for example with 16x speed.

I guess I need a good user interface for editing these curves on the system now!

Cheers,
Airic