LEGO Mindstorms Programming General Discussion

[TasV]

quoted from http://education.lego.com/en-au/preschool-and-school/secondary/11plus-mindstorms-education/faqs-and-technical-support

Q:What do I do when an exclamation mark appears on my block when I open an old program?

A:Download and run your program - in most cases your robot will behave as expected. If you suspect it behaves differently replace the block marked with the exclamation mark with a new block from the pallet (remember to configure it the same way).

The exclamation mark only appears in NXT 2.0 and indicates that you have opened a program originating from NXT v1.x. The exclamation mark will only appear on the following blocks:

File Access

Message Read

Message Write

Number To Text

Numeric Comparison

Numeric Operations

Range

Rotation Sensor

One of the differences between NXT 1.x Software and the NXT 2.0 software is that the NXT 2.0 uses Floating Point operations whereas earlier versions uses Integer operation. This can in rare instances introduce inaccuracies in the robots behaviour.

Apparently the Bluetooth block does it as well if you are using EV3 instead of NXT.

[Jim]

Something to watch closely:

http://hempeldesigngroup.com/lego/2013/09/25/making-hacking-accessible-lego-mindstorms-ev3/

-----

What I’ll be unveiling over the next few weeks and months is a system that satisfies the needs that the official LEGO MINDSTORMS programming environment cannot fulfill. These include being able to:

Program the brick in a variety of languages

Program the brick from a tablet or other non-supported device

Solve complex algorithmic problems using commonly available tools

Upgrade the brick software to have exactly the mix of tools you need

My past efforts, including pbFORTH and pbLua required Level 3 Computer Programmer skills to use, but sometimes needed level 4 Kernel Hacker skills to debug. So it’s no surprise these tools did not get much traction.

What I’ll be releasing allows the Level 2 Daily Computer Users to finally get a handle on real programming tools for robots. They might need some help from a Level 3 friend to set up the microSD card the first time, but after that it’s a piece of cake.

My toolkit will:

Fit on a microSD card. You’ll be able to plug the microSD card into your EV3 and not have to change the actual firmware in the EV3 brick. This is a big deal.

Allow you to plug almost ANY wifi dongle on to the EV3 so you can communicate with the brick, and the brick will be able to communicate on your network.

Allow you program the brick using a command line interface over a standard SSH encrypted stream. So Windows users can use PuTTY, Linux users can just ssh to the brick, Mac users – I have no idea but I’m sure there’s an ssh terminal hiding in those fancy machines somewhere.

With ssh, even Android and – wait for it … Blackberry users will be able to write and edit programs right on the brick! So there’s no need for IDE’s and complicated, buggy, frameworks

[JM1971]

I'm interested in EV3 and was wondering could I for example program manoeuvres into rock crawler or even get it to follow obstacle course?

Doc_Brown is making rock crawler course and doing a very good job (http://www.eurobricks.com/forum/index.php?showtopic=86580&hl=), but could people control cars on that from the Internet like in a race?

[Jim]

It would be difficult to modify the Crawler with an EV3 without making it top heavy. But one could create a different crawler, built around the EV3. The crawler would need loads of sensors to be able to navigate the course properly.

It would be possible to control the crawler via internet, but the lag would prevent from driving it properly.

So theoretically yes, practically....doubtful.

[Becs]

Hello everyone,

Out of fear of running out of IR-channels on my Dunderbygge, I thought about using my two NXT 2.0 to control the forwarder.

I've build myself a remote with two motors as input for steering and throttle. The forwarder got two motors for drive and one for the articulated steering.

The problem is I have no experience of programming them. I searched on the web for some guidance, but most of it just confused me. I did find a working program, but it was for some skid-steer model.

So I wonder if anyone could help me, please?

Becca

[JM1971]

Hello everyone,

Out of fear of running out of IR-channels on my Dunderbygge, I thought about using my two NXT 2.0 to control the forwarder.

I've build myself a remote with two motors as input for steering and throttle. The forwarder got two motors for drive and one for the articulated steering.

The problem is I have no experience of programming them. I searched on the web for some guidance, but most of it just confused me. I did find a working program, but it was for some skid-steer model.

So I wonder if anyone could help me, please?

Becca

Working examples are a good place to start, something you can try and then change stuff to see what happens.

[Becs]

Well, the commands for the drive motors I think I understand and can fiddle with. But the steering I don't know how to do. I want it to be propotional to the control on the remote.

[Jim]

Hi Becca,

I am not very sure what you want to accomplish. The Dunderbygge is controlled via IR? Or does the Dunderbygge have an NXT unit?

Can you give me a little bit more details?

[Jim]

Do you want to control the Dunderbygge via IR using the NXT? Or does the Dunderbygge also has an NXT unit?

[Becs]

To clarify, the Dunderbygge will be only IR controlled. Meaning I might have no channels left for a second model, a forwarder.

I thought about using a NXT for the forwarder with two motors for drive and one motor for articulated steering. I got a secong NXT to use as a remote.

[07jkearney]

To clarify, the Dunderbygge will be only IR controlled. Meaning I might have no channels left for a second model, a forwarder.

I thought about using a NXT for the forwarder with two motors for drive and one motor for articulated steering. I got a secong NXT to use as a remote.

Here is a good tutorial on making a proportional steering remote with another NXT (connected via bluetooth): http://nxtprograms.com/NXT2/steering_remote/index.html

[mikezang]

I have a nqc program as below, it used RCX IR and light sensor as proximity sensor, it is very perfect.

// proximity.c
#define THRESH 50
#define MSG 255

task main()
{
　　int oldValue;

　　SetSensorType(SENSOR_1, SENSOR_TYPE_LIGHT);
　　SetSensorMode(SENSOR_1, SENSOR_MODE_RAW);
　　SetTxPower(TX_POWER_HI);

　　while (true) {
　　　　oldValue = SENSOR_1;

　　　　start Send;

　　　　if (abs(SENSOR_1 - oldValue) > THRESH) {
　　　　　　PlaySound (SOUND_CLICK);
　　　　}

　　　　stop Send;
　　}
}

task Send()
{
　　while (true) {
　　　　SendMessage(MSG);
　　}
}

because I want to use brickOS to control my train, how can I convert it to brickOS? I tried but not successful, does anyone help me?

[Fugazi]

Although this is of interest to train fans, I feel that your question would be best answered in the Mindstorms area of our forums. I will be moving this shortly!

[mikezang]

Although this is of interest to train fans, I feel that your question would be best answered in the Mindstorms area of our forums. I will be moving this shortly!

Thanks, maybe this thread is suitable. I hope that I can get what I need...

[Jim]

I am afraid I have no hands on experience with brickOS.

brickOS isn't even in the index

(I will add it)

[jaxne]

I have recently started building with Technic again and are new to the PF-system and Mindstorms EV3. I haven't been building the last 10 years since I was a teenager using Mindstorms RCX and motors and 9 V analog electronics. I have now bought EV3 and some technic kits with PF M motors. My plan is to build some advanced robot using this but there is one problem.

I want to use one output on the EV3 to control switching on/off the PF-motors with own power supply. It will be several motors that are on/off at the same time driving different things with copnstant speed, so I only need one control signal for on and off for all these. I want to save outputs and don't want to use one output per motor, and I also not want the battery in EV3 to drive to many motors. Is this possible with some LEGO parts or do I need to build some own switch for this?

Construction an own switch will be no problem if I found more specifications of the outputs on the EV3 (I'm an electronics engineer), but I want to use only LEGO as much as possible.

Is the only way to drive one motor per output on the EV3 using some EV3 to PF converter? (I think I have seen this, but can't remember the part number). Or do anyone have some better recommendations for me?

[CopyCatz]

This IR transmitter allows NXT units to control PF IR receivers, I got one cheap and am waiting for hitechnic to make it EV3 compatible, which they said they are working on, but apparently it's a little more complex than the other sensors they make.

http://www.hitechnic...ion&key=NIL1046

Edited October 18, 2013 by CopyCatz

[Jim]

Hi Jaxne!

Welcome to EB.

Why don't you introduce yourself in this topic:

http://www.eurobrick...hp?showforum=17

I will be moving this question to the Mindstorms Programming topic shortly. This is where you can ask questions about programming Mindstorms.

You can also take a look at the Mindstorms Index for more information about Mindstorms topics.

Regarding your question; CopyCatz's answer is exactly what I would have answered

[jaxne]

I will write little more about myself later on today when I get home :)

I never thought about using IR, thats a great idea! :)

[Jim]

I am contemplating using IR in my robot project as well. I need some small rotating motors, not necessarily EV3, so using IR will open up lots of possibilities.

[CopyCatz]

It's the most efficient solution; sacrificing 1 sensor port to control 8 or more pf motors plus the 4 EV3 motor ports still available. Should make a nice robot :)

[Warongrtd]

Well, what I am interested in is the mentioned barcode reading add-on, because I want to program my own barcode creating application, but I am a newbie to programming, so, can you offer me some detailed samples?

[jaxne]

Which programming environment is recommended to set up for programming in C/C++ or C# using Mac OS X? Monobrick seems like an interesting choice even if I'm more used to program in C/C++. But when I start reading about how to set up it seems like I need wifi. Anyone using this who can tell if I really need wifi using Monobrick? Or maybe have ideas for other environments for OS X.

[nxtstep101]

I recently attempted to upgrade my NXT to the newest software, after I clicked download it located the brick then began installing. However, a couple seconds later the NXT screen went blank and a gentle clicking noise started. I left it plugged in for about two hours and when I came back it was still making the clicking noise and no further download progress was made. I have heard of the notorious "clicking brick syndrome" before, so I followed the steps to attempt to fix it. However, each time I try to re-install the NXT firmware it fails to locate the brick. Anybody have any idea on how to fix this? Also, it should probably be noted that the laptop I am currently using is running Windows 10, could that be the problem?

[Paul P]

Hi nxtstep101 use brixcc to download the firmware, use an earlier firmware version then when you have it up and running you can upgrade to a later version. I have done this with two of my NXT bricks. that went into SAMBA mode