Arduino using WPI library?

[RyanN]

Originally Posted by DominickC

Hmm, alright. We're going to need a higher level of control over PWM output to our motors than a simple character. I was hoping to be able to hook up a joystick and read values off of it. This is pretty much a requirement for the project, we're going to need joysticks.

In the event of communication/power loss, we've designed the blimp to be able to coast downward at a safe speed so as to not hurt anyone or damage the airship too much. So I'd have all motor outputs be 0.

I don't have any experience with C, but I've looked at a bit of it and feel like I'd be able to pick it up. I can also learn the Arduino language. I don't know if there are any libraries for my project, but hopefully I'll be able to learn enough to do what I want to do.

Of course, I might as well try to use something off of the WPI library before I discredit it all together. It might work, but I'm certainly not reliant on it or LabView.

EDIT: If I were to use C, would I be able to use the WPI C++ Robotics library?

You can only use the WPI Library for the CompactRIO basically. It like "trying to install MS Word on Linux. It just won't work."

[DominickC]

Hmm, that's a shame. I guess I'll go library hunting now!

EDIT: I've taken a look at the WPI Joystick and Camera palate, and I don't see anything which would restrict the platform to the FRC cRIO, however I believe the Camera palate will only work with the Axis M1011 or 206.

[RyanN]

So I haven't forgotten about you. I've been playing with my Arduino Mega 2560 over the weekend. I got away from the LabVIEW Interface for Arduino because of its various glitches, speed, etc... The Arduino is actually really easy to program. I was told this many times, but I never really tried it out.

It has the power of C++ with the simplicity of the Basic STAMP from Parallax. There's tons of open source code and libraries available, so you can probably find a project where someone implemented an Arduino in a blimp.

As far as communication and control goes, you can still use LabVIEW. You'll have to develop your own communication protocol for it, but it shouldn't be too bad.

Some things to keep in mind. It's usually considered good practice to always include some type of a sync word, meaning that you have a number that increments with each packet of data you send. That way, if you detect a packet out of order (number sent was less than last packet), you'll trash it.

I've been using the BlueSMiRF RP-SMA. There's little configuration to get it working fairly well. I haven't found the max distance yet, but to note, this isn't FCC Legal, as they have changed the antenna configuration.

Because we have changed the antenna configuration on the Bluetooth module, the FCC certification is no longer valid. But the module is completely suitable and legal for all home, hobby, and research applications.

I find the best way to send data is using a new line '\n' (ASCII DEC 10 or HEX 0xA) as the termination character. You can create an event driven while loop in LabVIEW using the termination character. On the Arduino side, you'll have the SerialEvent() function, which is triggered on a serial receive event. You can then check to see if the newline '\n' character was sent, and if it was, then process your data.

Here's the format I would use:

"[SYNC_WORD_32_BITS][MOTOR1_VALUE_8_BITS][MOTOR2_VALUE_8_BITS]...[MOTORN_VALUE_8_BITS][DIGITAL_OUTPUTS_GROUP_8_BITS]...[DIGITAL_OUTPUTS_8_BITS][CONTROL_WORD_FOR_SPECIAL_FUNCTIONS]\n"

For receiving back data, the format will be very similar. You'll have a sync word and sensor values. You'll want to look at an ASCII table, and you should note that sending over raw data values is a no-no for the BlueSMiRF unless you format it properly. You'll have data loss, as it doesn't pass through some values. If one of your sensors sends back a 10, then you'll trigger it to send the data. Try to convert all of your sensor values to ASCII text and ASCII number values. It uses more bandwidth, but it should still be relatively fast.

Let me know if you have any questions. The best way to get started with the Arduino is to just get started. Play with it, send numbers to it, try to echo back those numbers, then add numbers. Make an LED turn on when you send it a center character, and make it turn off if you send another one.

[DominickC]

Gearing up for WPI, will have more time to invest into this project after.

I was planning on using the Ethernet shield to plug it into a router configured to act as an Access Point, and pump info to the Arduino via TCP/UDP. Will this suit my need?

I had my school pay for the Arduino, so I'm waiting on whenever they place the order in...unfortunately, nothing has come to my doorstep yet.

[RyanN]

Originally Posted by DominickC

Gearing up for WPI, will have more time to invest into this project after.

I was planning on using the Ethernet shield to plug it into a router configured to act as an Access Point, and pump info to the Arduino via TCP/UDP. Will this suit my need?

I had my school pay for the Arduino, so I'm waiting on whenever they place the order in...unfortunately, nothing has come to my doorstep yet.

I looked at the Ethernet shield library, and it all seemed pretty easy, but I never tried it.