ZigBee controlled RN-1

[subpilot]

I don't know about Forth being "easy to understand". It sure isn't very readable. You have to keep track of what's on the stack and can't just immediately see what's happening. That said I'm starting to get a handle on it and can see the merits. Here's a bit of Isomax code to read the servo position feedback (on a timer pin).

: GETPWM
8 0 DO TD0 OFF LOOP ( 10uS pulse out
8 0 DO TD0 ON LOOP
3 0 DO TD0 OFF LOOP
TD0 SET-PWM-IN ( set up TD0 as input to measure the pulse )
DECIMAL
200 0 DO ( loop looking for servo return pulse )
TD0 CHK-PWM-IN ?DUP
0 > IF . LEAVE THEN ( pulse received so bail
I 150 > IF 0 . LEAVE THEN ( if no pulse after 150 loops ~5mSecs then bail )
LOOP
;

I think the Servopod will prove to be a great controller for the RN and the support from Newmicros is great.

[DanAlbert]

I read the code and understood it perfectly.
I guess it's like anything else, it seems difficult unless you grew up on it. I did a lot of Forth as a youngster.

Does this Forth have any ISR capabilities?

[CaptKill4Fun]

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[CaptKill4Fun]

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[CaptKill4Fun]

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[DanAlbert]

Thanks for the pic change.

I wasn't sure how to capture yours, so I just reloaded a cropped and shrunk version.

It does look better.

I did check out the microsoft software but wasn't sure what exactly i could use it for.

Maybe the Robot Simulation would be cool.
I just worry that if Microsoft gets too involved we will be needing megabytes of flash and ram to run our bots. I saw a speech at RoboNexus that a Microsoft person gave about the wonders of Microsoft's Real Time WindowsCE. Personally I've yet to see a RTOS that can handle an interrupt as fast as a small assembly or C program. In my opinion, these RTOSs that handle an interrupt in 20 mSecs are really not "real time".
20 uSecs is more of what I call "real time"....for now anyway.

[Bob]

Hi, I'd like to enquire further about any developments with the XBEE. I'd really like to replace the USB Serial wire on the KRH-2 with a wireless link. Apparantly this is doable, but not by me (hardware challanged). Is anybody working on a product or a kit (I can solder) that can accompplish this?

Thanks,
Bob

[elizabeth1086]

Hello, I am new in the handling of the robot. I am working in a project that is the design and implementation of an algorithm distributed of real time in wireless enviroment, I used the Robonova to prove this algorithm. I am still developing this algorithm. Well, we need to use Xbee like wireless modules. I need to adapt the Xbee to the controller board of the robot.
I see that you have developed it.
I wanted to now if you have some material that could orient me about this?

[DanAlbert]

There are two boards I built up. One that goes inside the RN head that is just comprised of a voltage regulator and 5 volt to 3.3 volt signal level converter for the XBEE board. If you have a PC controlling the RN and it has a compatible ZigBee transmitter/receiver then you can send about 4 ascii characters per second with RoboBasic. It takes about 250 mSecs for RoboBasic to figure that there is a byte on the serial port. It is "basic"ly brain dead.

The other board has a PIC MCU on board that decodes the SPI interface of the PlayStation 2 controller.

Hope this helps.

Can you give me more info on your project?

Dan

[elizabeth1086]

Thanks Dan.
Look, my project fundamentally is a algorithm designed in java that it's based in a protocol Implicit EDF, this algorithm it's in real time and send messages trouhg of wireless comunication using modules Xbee in each computer and the robonova must have a Xbee too. This Xbee must receive information and send through serial port this information to the robonova for that execute a routine.
I will need make the first board that you mention me. Robonova is only a receptor of information. I am trying to make this board that you build it, but I don´t know precisely how to make, but with the information that you provide me I hope can, if not I will need buy this.

[DanAlbert]

Hi elizabeth,

Do you understand that the RoboNova can only accept 4 bytes per second on the serial port that the ZigBee is connected to??

Will this be fast enough for your project?

Dan

[elizabeth1086]

I think so, because I have just four nodes and each node send one byte to the robot in differents times, I don´t know if this work because this project it's in diapers, let`s say!.

I need receive one data only to prove that the cominication work through xbee and robonova.

A question:
You used a MAX682 to regulate the voltage?

[DanAlbert]

i don't think i used a maxim part for the voltage regulator. I used an off the shelf surface mounted 3.3 volt reg I got from either digikey or mouser.

For the input signal line I used a voltage divider made from two resistors.

The 3.3 volt output line works OK with the 5.0 input since it is above the 2.5 threshold.

Do you have the XBee boards? After RoboGames next week I will have time to build up some boards if you just want to buy one. I don't make any money on these. I sell them at my cost. Unfortunately since I made a small gty. The PC board cost me about $10 and the other parts about $2.00. What country do you live in? I also have ZigBee boards I paid about $20 apiece.

Dan

[elizabeth1086]

Hi Dan.
I live in Colima, México.
Idon't know if you can send me the board to Mexico.
I don't know if I can buy the board. But I would warn to you the next week.

[elizabeth1086]

Hi Dan.
I would like to know , if I buy the board with the xbee that you made, when you could send it to me and how much with the shipment to Colima, Mexico?.

Thanks.