Sioux Embedded Systems is organizing an event called “Technique in Automotive”. At this event, our Sioux.NET on Track expertise group will give a demo. Since trains are forbidden at this event, Jan Willem van Silfhout and I came up with the idea to use the PUI-stols for a race between two Mindstorms EV3 trucks. In the drawing you get an impression how it will look.
With the PUI-stols you can shoot your truck in four directions:
As you can see, you cannot move the truck in a straight line. It is only possible to go left forward, left backward, right forward or right backward. So it won’t be easy to get the truck to finish…
If you are in the neighborhood, you’re welcome to visit our event with your family. For more information and registration visit the Sioux.eu webpage (Dutch only).
Remember these PUIstols? Jan Willem van Silfhout designed these two prototypes out of his EV3 Education set.
The PUIstols were designed from the elements in the Education set. For our Sioux.NET on Track project, we have four Home Edition sets (so, we are a sponsor of all AA battery manufacturers ;-). I tried to rebuild the PUIstols that Jan Willem designed from our Home Editions, and came to the conclusion that this was impossible. There is simply said very few overlap in the elements…. with the Home Edition elements I came up with the two PUIstols (only the white bricks for the numbers came out of my own Lego):
From the rest of the Mindstorms Home Edition elements, I made also a PUIstols standard:
The PUIstols have quite a narrow beam. In the test program I wrote on the EV3 with two Infrared sensors, it all works fine. The final version will have four Infrared sensors, in the same colors as the wagons that carry the candy on the track.
Sunday February 2nd, Sioux Embedded Systems is organizing a Lego Education workshop for their employees, partners and children. We bought 17 Lego EV3 bricks and 7 WeDo. Plus for both systems the expansion set. It was a car full of Lego:
Surrounded by all this Lego, I had the vision of connecting all these stuff together. Making it more easy to connect the PF motors to the Mindstorms technique (currently, we use the HiTechnic IR Link to control PF motors). Since the EV3 has an USB port, a Linux programmer should be able to modify the firmware to control the WeDo Hub. And therefore, the Mindstorms EV3 should be able to control PF motors. Of course, it would mean that the Mindstorms Programming Environment should also be extended with an “WeDo programming block”.
Maybe, some day…..
Our track layout uses automated switches. The current version that we are using (three in total) is based on the NXT motor. Using a (NXT) touchsensor, the PC application can determine the ‘status’ of the switch (i.e. in which direction is the lever positioned):
Since we will need four switch drives and based on the EV3 (so it can be controlled by one brick), I thought it would be a good moment to redesign the drives.
I came up with a modular drive system. I designed a ‘fixed’ part without the motor that converts the rotation into the lever movement. And four different motor modules that can be connected to the axle:
- Based on the PF motor
- Based on the EV3 M-motor
- Based on the EV3 L-motor
- Based on the NXT motor
I am going to design a separate module for reading the lever position, one based on the EV3 Touch sensor and one based on the NXT Touch sensor.
If you want the building instructions of these modules, please do not hesitate to contact me.
Our final track layout will consist of four NXT bricks and four EV3 bricks. If we would connect all the bricks using Bluetooth, we expect the connections to be unreliable. To prevent this problem from happening, we bought the recommended Netgear dongles (about 15 euro per dongle) to connect the four EV3 bricks using WiFi.
A major issue that arises with the WiFi dongle is when connected to the EV3 Brick, the dongle sticks out from the side of the EV3 brick, getting in the way of everything. Allowing it to be easily knocked out from the EV3 Brick’s USB Socket. Therefor, I used an USB ‘around the corner’ adapter:
You would expect: plug in the USB adapter, plug in the dongle, setup the EV3 software and ready. No… it took me about an hour to get the dongle working. I found out that the USB adapter was the problem. The adapter connecters are too short to function properly if you insert the dongle completely. If you insert the dongle leaving ~2 mm of space, then it works fine. So, I will have to look for other adapters
But when it works, it is a relieve to have the USB cable not lying around anymore around my table. I can recommend this feature.
One of the base elements of our layout, is the possibility to choose a color. Do you remember the previous Physical User Interface of 2012 and 2013:
Well, I can now proudly present the PUI for 2014 (created by Jan Willem van Silfhout), the Laser P(U)istols:
The base of the pistol is a remote control 8885 and the bricks from an EV3 Education set. The trigger of the black pistol is connected to channel A and the trigger of the white pistol to channel B, this will make it possible to use one channel for both pistols. On the track, four infrared EV3 sensors will be installed to represent the four colors that can be chosen. With these pistols, two visitors can simultaneously ‘shoot’ and choose a color. Which is the start signal for the train(s) to run and to pick-up the colored wagon with the candy (or whatever).
The next step is to design four color housings for the infrared sensors… (to be continued)
Below you find a closeup of the train buffer with the Mindstorms touchsensor. If the wagon hits the buffer, the NXT brick sends a message to the train that it should stop, and to proceed to the decoupling phase.
In the Youtube video you see a test run:
- Train drives towards the train buffer
- Wagon hits the buffer
- NXT brick sends message to the NXT on the train.
- Train stops
- Train starts decoupling of the wagon
- Train drives away
Note: in the final version, the train should slow down before hitting the buffer stop.