PBP projects for R/C models

[Kenjones1935]

I need to do some studying - PBP - ASM - 16F887.

My original purpose for this project was to devise a kit and a collection of lesson plans that might hook middle school students into the thinking and documentation processes common to Science Technology Engineering Math.

I hoped to give them an insight into, "How things work" this, the 21st, Century.

Thanks again. I have my work cut out for me.

Ken

[mackrackit]

Just some thoughts...
You seem to be very close with your code, the kids are going to love it.

Have you seen this?
http://www.picbasic.co.uk/forum/cont...rial-backpacks
What if you did something similar, a "car backpack" ?
Then the parameters that the kids need/want to change to make it their own could be done with the demo version of PBP.
http://melabs.com/pbpdemo.htm
They would not have to learn the whole car code but learn enough to get started.

[Kenjones1935]

I do not know the term "back pack".

Are suggesting that all the students' cars contain standard PBP code (one license). To experiment with sonar calibration and steering reaction time relative to changes in car velocity and 'race' course size each student has a set of definitions that can be downloaded via MPLAB or PIC kit 2 programmer?

I have learned how to write data in the EEPROM section to be read whenever I hit the READ button. That's all the interaction I have mastered.

Ken

[mackrackit]

With a serial LCD backpack the chip that runs the LCD is "attached" to the LCD. Parallel LCDs use at least six pins from a MCU so a lot of times the project MCU does not have enough spare pins.
Use one pin from the project MCU to send data to the LCD MCU serially.

Are suggesting that all the students' cars contain standard PBP code (one license).

Yes, base code written by you.

To experiment with sonar calibration and steering reaction time relative to changes in car velocity and 'race' course size each student has a set of definitions that can be downloaded via MPLAB or PIC kit 2 programmer?

Yes again, these commands will be downloaded to a second MCU that communicates with the main MCU that you programmed.

The students will be able to use the free demo version and not be able to "mess up" the main chip.

[Kenjones1935]

If I can down load to another PIC why can I not download to my main PIC? I have no problems with pin count. I am not using a PIC KIT. I am using a naked 44 pin 16F887 and a solderless prototype board.

It would seem that part of my code could react to some signal from the USB serial port and download parameters into itself. I have not the faintest idea how, however.

Another thought: My code is written so that all the constants are defined in the preamble before "main:". A class of eight to ten students, I imagine, would be broken into four or five teams. They could change parameter values using a text editor, burn into a thumb drive (or use the school's internal network), cut and paste the data into their PBP code on the licensed machine, compile, plug the USB connector into their car, and download using PICKIT programmer. WRONG? Against the rules?

I never got MPLAB to work as a ASM compiler and chip programmer.

Ken

[Ioannis]

Ken,

1. Why are you bothering with assembly? Do you need it?

2. If you have to work on one licensed PBP, then do this. Connect an LCD on the PIC (I think you have plenty of pins) and 2-3 buttons and let he students change parameters with a menu driven software on the PIC. Then the LCD can be disconnected and leave the PIC running with new parameters.

3. To program a chip you need a programmer. Which one is your favorit?

Ioannis

[mackrackit]

Sorry Ken, I did not mean to confuse things.

I was trying to find a way for the kids to be able to work on a portion of the code with out having to use one machine (PC) to do it. Sounds like you have a work around for that.

MPLAB should do ASM with a standard install. The language may need to be set under the projects tab.

[Kenjones1935]

A couple of things:

1. Part of STEM at middle school level is "How things work". Computers including PIC's are "digital" - 1's and 0's. Each step away from pure machine language hides this basic fact. That physical phenomena like sound and light can be represented by 1's and 0's is my point. What is analog? What is digital? These are not part of this project, but it shows where I am thinking. (What is an echo and how can its response time be characterized in binary. What is hexadecimal?)

My PIC is on a prototype board inside the plastic body of a radio control car. This car body has holes for the two sonars, the six lead connector to which the USB connects, and for screw driver access to the speed controlling potentiometer.

Velocity is of the essence. Speed is the hook. That and the model level RC car's miniaturization of automobile mechanics. Turn over a model level RC car. Get in a grease pit and look up at a modern car.

The 1997 Cadillac Deville has 13 or more computers on board depending on which options in contains. Imagine the 2010 version. I think the 2010 Lexus car can back itself into a parallel parking spot. HOW DO THINGS WORK?

Ken

[Kenjones1935]

Is there a freeware version of C available for the 16F887? Is there a library available?

Is there a freeware version of C available for another more sophisticated PIC? I think I see something in the "MPLAB C18 C" reference in the MPASM Assembler HELP GUI. Is there a PICKIT that carries a PIC for which there is an available C package?

Ken

[ScaleRobotics]

Is there a freeware version of C available for the 16F887? Is there a library available?

Is there a freeware version of C available for another more sophisticated PIC? I think I see something in the "MPLAB C18 C" reference in the MPASM Assembler HELP GUI. Is there a PICKIT that carries a PIC for which there is an available C package?

Ken

I've never used any of the Hitech compilers, but there is Hitech C Lite version:

pic10-16 http://www.microchip.com/stellent/id...cName=en542849

And for more power full chips..... But for your project, I don't see why you would need anything more than a PIC18, or PicBasic for that matter.

PIC32 http://www.microchip.com/stellent/id...cName=en542866

Then, there is alway StickOS, which I think would be great for your kids starting out to learn how to control a MCU in basic, with no cost for development tools. Only problem is you can't (as far as I can tell) do anything else while you are sending a servo a signal. But might be interesting as another tool, or to talk to a main (backpack like) chip. Easier to learn than PicBasic.

http://www.cpustick.com/

[mackrackit]

Not C...
I have been wanting to try this
http://www.crownhill.co.uk/level3.php?cat=270&sec=1
http://www.myamicus.co.uk/content.php?117-Documents

[cncmachineguy]

Great find Dave, and if I read correctly, still makes use of PBP

[mackrackit]

Great find Dave, and if I read correctly, still makes use of PBP

Or this
http://www.myamicus.co.uk/content.ph...CUS18-Compiler
FREE!!!

[Kenjones1935]

scalerobotics wrote:

Only problem is you can't (as far as I can tell) do anything else while you are sending a servo a signal.

That's OKAY. Right now all I do is:

LOW trigright
HIGH trigright
HIGH trigright
HIGH trigright
LOW trigright
PULSIN echoright,1,rangeright 'measures the range in 10uS steps
PAUSE 10 'Wait for ringing to stop - read SF05 spec.

This seems to work flawlessly.

Ken

[ScaleRobotics]

Here is some more info about StickOS with some youtube videos by the guy the wrote it. Pretty cool stuff.

http://www.picbasic.co.uk/forum/show...9397#post89397

[Kenjones1935]

http://www.cpustick.com says in its 2nd paragraph:

Additionally, when coupled with an optional Freescale MC13201 ZigFlea™ Wireless Transceiver, the MCU may be remotely controlled by another MCU, via a telnet/rlogin-like interface, eliminating the need for a direct connection to the host computer altogether. Also, BASIC programs may trivially remotely access variables on other MCUs, enabling the use of “remote pin variables” or other forms of inter-MCU communication.

Do you think I could get the robocars to communicate with each other using this? This could add greatly to the number and types of games or competitions we could devise. All this with 8K of program memory? Really?

Ken

[ScaleRobotics]

I don't know how far the zigflea can transmit and receive. But StickOS makes it pretty easy to connect devices that control each other. The first and I think the second video talk about hooking the remote zigflea up.

Here one piece of hardware you could use:
http://www.sparkfun.com/commerce/pro...oducts_id=9645

And pretty soon the ZigFlea should be available for it:
http://overtone-labs.ning.com/forum/...flea-for-cui32

I don't know how much room you are left with with StickOs, but you need to get up to PIC32MX4 to use it. The chip has 512K programmable memory and 32K ram.

[Kenjones1935]

My cars use the same solderless protoboard as CPUstick uses here:



On the tail end I have velcro'd the RC radio receiver. There is plenty of room inside the car's outer body to add a horizontal zigflea if I can rig the connection as 0.1" centers.

I do not understand the above package. How about I start with this from EMCelectronica? It looks like it will plug into my protoboard and not give me stuff I do not need. At ~50EUR it is not inexpensive. Do you think I could put the thing together myself as I have done with the 16F887?



Ken

[ScaleRobotics]

EMCelectronica's price is ok, but their shipping really gets you. The CPUStick is 49 Euros, but shipping is 52 Euros ... ouch! Of course, it could be their store is set up wrong, and shipping wouldn't really be that expensive.

Here is one that fits your breadboard better than the other Sparkfun device:
http://www.sparkfun.com/commerce/pro...oducts_id=8971

I have trouble with some 44 pin devices, so I am a little scared of soldering one of these big guys. I would use an off the shelf product for testing, then if it looks like it would do the job, you could have some boards made and try some soldering.

[Kenjones1935]

Thanks for the tip. The board looks OKAY, but only if I can solder pins into those holes and plug the thing into a solderless proto board. Of course some of the pins across the bottom would not have matching holes.

Oh, I see. The picture of the red board in your "http://www.sparkfun.com/commerce/pro...oducts_id=8971" is the same as the picture of the green board in my previous posting. True? Do you think? The price there is OKAY if shipping is reasonable.

Ken

[mackrackit]

There is a link on Sparkfun's web site going here
http://www.schmalzhaus.com/UBW32/

[ScaleRobotics]

Yes, these are the same devices. 0.1" on the spacing. They are made for breadboards. More about them here:
http://www.schmalzhaus.com/UBW32/

[Kenjones1935]

What else do I need? I am confused but very impressed by the young man in the video. I'll get the ZIGflea later.

Ken

[ScaleRobotics]

What else do I need? I am confused but very impressed by the young man in the video. I'll get the ZIGflea later.

Yes, me too!

That should be all you need. However, this one does not come with StickOS installed. But you can use your PicKit2 to install StickOS firmware into it. And, by doing that, you will get the latest 1.80 version. You will need to download a windows driver from this page CPUStick.inf : http://www.cpustick.com/downloads.htm

But with that, and hyper terminal, you can start writing some code. Oh, and you won't get a manual either, so you will have to print one.

Walter

[Ioannis]

Hi Ken. I do not see why you should leave PBP and start another similar language and your project all over again.

If you do need RF communication between nodes maybe a Zigbee modules or RF transceivers can give you a good solution without almost a line of code.

Look at Digi modules (Zigbee or not, does not matter) for out of he box communication. Other brands also exist, many I can say.

Ioannis

[ScaleRobotics]

I do not see why you should leave PBP and start another similar language and your project all over again.

I wouldn't normally suggest it, as PBP can do just about anything. But here is why I think it might be a good idea in this case.

Configs are confusing for adults, I would hate to frustrate middle school students. This would keep them from having to worry about those.

PBP kind of expects you to read and understand the data sheet. StickOS would just require them to get read the device pinout. They could just start with the data sheets for their sensors, and not be overwhelmed by a 200 to 500 page data sheet.

They would not have to worry about setting ADCONx, trisx, cmconx etc...

With StickOS, they can just say:

10 dim pot as pin an5 for analog input 
20 print "potentiometer= ",pot

Now here is some PBP code that does a similar function:

Define ADC_BITS     10  ' Set number of bits in result
Define ADC_CLOCK     3  ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50  ' Set sampling time in uS

adval Var Word          ' Create adval to store result

   TRISA = %11111111    ' Set PORTA to all input
   ADCON1 = %10000010   ' Set PORTA analog and right justify result

mainloop:
   ADCIN 0, adval       ' Read channel 0 to adval
   serout2 PORTC.6,396,["Value: ",DEC adval,13,10] ' Display value
   Pause 100            ' Wait .1 second
   Goto mainloop        ' Do it forever

End

And pretty high up there in my opinion is the cost. I know the school my son goes to has trouble buying pencils and paper. They would pretty much need everything donated to be able to do it. I think Ken said the cars were $80, this CpuStick is about $40. The PBP software is $250. So the cost per unit is $120 with StickOS vs $370 for PBP. That's over three times the cost. So, for the same cost of having 30 students share 10 PBP units (one kid does the work, while the other two watch), they could have one for each kid in the class.

[Kenjones1935]

There is already an educational oriented company, www.Ten80Education.com, which uses model level 1/10 scale radio control cars. They focus on automobile related engineering, toe-in, tire friction, gearing, power usage, damping, suspension. The car they use, the HPI Sprint, costs about $200 retail. Coincidentally I chose this same car for my project. I hope to integrate my PIC car into their curriculum.

It is the add on cost for my project that must be controlled. The sonars cost $28 each. It is really too bad that the PBP cost is just for a one PC license.

Big question?? What kind of games could our robocars play if they could talk to each other over zigFLEA?

Ken

[Kenjones1935]

I use the model level car because its steering and wheel drive is based on proportional PWM signaling. This I need for the wall following (at speed) trick.

The much cheaper ~ $50 ~ 1/10 scale toy level car has bang-bang steering that motor control. If that is all we need for the learning game, then the total cost comes way down. These cars are FAST.

Ken

[Ioannis]

These cars are FAST.

Yeah, but with very little control on the steering. Like you described it as bang bang (to the walls)...

The fuse settings, or settings in general may be solved by an include file made by Ken and students all have to do is just ... include it.

So they are left with the main body of the software. Which comparing to stickOS is a little more difficult. But you have interrupts and much faster execution time...

About the cost, well, OK. 250 is much money, but good things cost...

Ioannis

[cncmachineguy]

I have been folowing this thread. I have a question about the steering: I get it's bang bang, but what actuates it? is it a spring returned solinoid or a motor? I am thinking there should be a way to pulse the steering to simulate proportinate control. Does it really go full left or right with just 1 frame of command?

Also, as Dave suggested, can you create it so the demo version could be used? Maybe write some subroutines to "include" so all the power of PBP isn't required.

Then if some of the students are really intrested and want to go further, they can be pointed to PBP for their parents to purchase? As a parent, I would gladly buy a copy for my kid(s) if they were to show me they actually wanted to play with it. It would be far better than an x-box orother such stuff.

[Kenjones1935]

The 1/10 toy level car has a spring loaded servo for steering.

The steering servo and the DC motor for the wheels are driven by + - 7.2volts. I have four coil driven DPDT relays doing this job. They are not fast, but they are robust and reliable.

Today I am thinking about teaching the teachers. I need to come up with lesson plan #1. I am imagining kitting some of my cars then asking the teachers to implement "HELLO WORLD" (whatever that is for one of my RC car PIC systems.)

Question for you all.
What would be a HELLO WORLD for a 1/10 toy level PIC'd car?

Ken

[mackrackit]

Question for you all.
What would be a HELLO WORLD for a 1/10 toy level PIC'd car?

Maybe one of the things you did for a Hello World?
Go to the end of a hall, turn around and come back.

[Kenjones1935]

I am considering doing a teach-the-teachers gig. The attendees would get Professional Development points. They should be allowed to take home their kitted cars.

The least expensive RC toy cars are about $25 retail. The most expensive thing in my present kits are the sonar sensors. What can I sense for less money?

Ken

[Kenjones1935]

Could a 'Nicera' IR Detector designed, "especially to detect body heat" enable my toy level cars to swarm together playing follow the human?

Imagine a teach-the-teacher class in a gymnasium where the HELLO WORLD application makes the students' cars follow the teacher as he or she tries to out wit it. (The teacher must be wearing a bikini while the students would all be dressed in their warmest winter finery.)

My 'All Electronics' catalog has IR DETECTOR for $3.90 each. Would this work? How sensitive are these things?

Ken

[mackrackit]

A light sensor would probably be the cheapest and easiest.
But the bikini thhhing is interesting...

[rmteo]

How about something like this to get kids interested in microcontrollers?

[Kenjones1935]

That seems the best so far. I have some light sensors.

The teacher has an open 150watt incandescent bulb and an extension cord. Hmmmm....

Try again,

The teacher has a portable roadside emergency light. He or she runs around the gym, the toy cars follow. Maybe the gym lights need to be dimmed.

The fact that TOY cars have bang-bang controls ought not to inhibit the PIC control code.

I like it. Why won't it work?

Ken

[Ioannis]

What is this thing americans have about this fish?

Maybe the culture is different, but I really cannot understand it.

Anyway as a project has fun!

Ioannis

[mackrackit]

What is this thing americans have about this fish?

I do not understand "fish".

[Ioannis]

Oooh well, I did it I guess!

I was watching another thread and answered this instead off. The other had a video with a talking fish....

Sorry!

Ioannis