New Controller Specs Posted
 

http://www.innovationfirst.com/FIRSTRobotics/edu-rc.htm

Key features are:
-Faster sampling
-More variable space
-Faster/Better processor
-Interrupts

If you look towards the bottom, an extra feature has been thrown in. The Robot Controller will be powered by its own battery. Now the RC won't reset every time when drawing high current...

Programming options in either Assembly or C.

Looks like IFI has been listening... and then some.

w00t!

ok, I see the specs there,

the drawing is for the EDU controller

the specs for the FIRST competiton controller are listed on the bottom in the table.

Cool! (when can we get our hands on one?)

hrmm.. yaknow.. if the actual compeition rc is powerd by its own battery.. that could help out if first wanted to say go to 24v ......
eh, just a brain blast of sorts

I think that's a mistake. Last year's EduRC used a 7.2V battery, while this year's isn't listed as using one.

<edit>
Oh. It was just changed. There will be a 7.2V backup battery on the FRC RC. Interesting.

And what about that TTL serial port? And bi-directional digital?

I'm getting excited.
</edit>

<edit again>
Oh. And it was changed again. Now they list primary and backup batteries. Well, I was right about there being a 7.2V batt on the new EduRC. :)
</edit again>

Were do we get the Microchip MPLAB [IDE]?

</> very excited about this....go C'ers! <\>

You can get the MicroChip SW developement tools for free from their website (microchip.com)

and that will let you program in assembly

Microchip C is not free though. They have a demo download, but I dont know what it does.

<drools>

MPLAB-C18 is basically an add-on to MPLAB which allows you to write C programs for the PIC18 series.
It comes with processor-specific libraries and libraries with functions for common uses (PWM, timers, ADC, USART).

The documentation is pretty good, as well. The demo version is only good for 60 days, though.

hrmm.. after reading a bit, what I was originally thinking wouldent work, they list it as a 7.2v backup battery..... i dont know much about pic s so i wonder.. is the ram that the pic uses to store the program volitile? or possably somthing else in the rc is?
:confused:

I checked the specs on their webpage:
http://www.microchip.com/1010/pline/...8520/index.htm

it has FLASH for program memory, and EEPROM space for program variables. that means your program can store information as its running, that will be there next time you powerup - so you could save things like your yaw rate sensor zero reading, or any other variables you need to fine tune your control algorythms.

the 7.2 'backup' battery is probabally what powers the controller (most likely regulated down to 5V or 3.3). Lke someone else said, this is probabally so the controller doesnt reset if your motors draw a large current spike. We will have to see how it all works together.

BTW, the EDU kit last year, everything ran off a 7.2V battery.

The controller has to run on at least 5V. The PWM outs have to put out 5V so that servos and speed controllers will work.

hrmm.. just another thought, if the battery does power the rc when the 12v isnt there.. would that mean that we can use the battery evean after the 9v mark where before the rc would reset (correct me if im wrong but i think its 9v)

I'm not sure about the 9v mark, but when the voltage goes down to about 6v or lower, the speed controllers will stop working.

yes, I think that would be the idea - if your main battery is pulled down, or starts going dead, the RC battery will keep the controls and radio link alive

since they call it a backup, Im guessing the 7.2V battey will charge off the 12V battery, so you dont have to charge them separately?

No news on the OI yet, is there...

I'm thinking it'll be the same, because of the lack of an OI for the vetern teams to use with the EduBot RC.

One thing that I'm not sure about though, what about the dashboard port. Will that change this year, or will it stay the same? I'm hoping we have control over it this year, but I haven't seen any information on that yet.

there is really no reason to change the OI. (well i guess i can think of a few)...


Hrmmm.... Whats up with the "PWM in"?

The Digital In/Out's got me thinking...
I wonder if we'll be allowed to interface the Digital In/Out from the eduRc straight to the Digital in/out on the Full RC for competition?
Then the eduRC could handle some low-level processing and data storage for auto mode, and the full rc would handle high-level processing, and main operation data...
Hmm...
I wonder if this will be allowed of not?
I'm tinkering with putting together some C headers w/ structures now, so I can get going as soon as we get our new RC :p
The fact that Vet's aren't getting new OI's pre-season is leading me to believe that there will be few changes to the new OI, if any. I assume the Dashboard port may change, and a new Dashboard program will be released.
Not much really needs to be done to the OI... Maybe a longer adapter cord? :D
Who Knows... :rolleyes:

Im quite impressed. I need to learn C for this, but it is worth the effort.

Also, since we (apparantly) can code in assembly, and I am quite fluent in x86 assembly, would it better for me to learn C or the PIC assembly?

Finally, I can't wait to see some default code.

If the FRC RC has a TTL serial port, wouldn't it be easier (and faster) to use that link to communicate between systems?

Also, if there's an imposed limit on price for external electronics, again, it might not be legal to use an EduRC in conjunction with the FRC RC, depending on its price.

you would definately want to learn C before you learn assembler.

assembly code is tedious and error prone.

You could almost certainly implement a faster data transfer protocol between the RC and an external microcontroller using the digital I/O than using a serial connection limited to 115k. Parallel I/O is nearly always faster than serial. However, it would indeed be quite a hassle.

Ah. Sorry. My mistake. It makes sense that a parallel system would be faster than serial.

Also, concerning the posted specs, shouldn't the PIC18F8520 be running at 40MHz, instead of 50MHz, as IFI says? The processor is listed as having a maximum Fosc of 40MHz, on Microchip's page.

<edit>
Deleted something stupid. Thanks to Matt Leese for pointing it out. :)
</edit>

That's true until you get to high transmission frequencies. Then crosstalk becomes such an issue that it's easier to send things over a smaller number of wires. This is why many computer interfacing technologies are switching from parallel serial (parallel ports to Universal Serial Bus; Parallel IDE to Serial ATA).

Now, obviously, that won't be an issue here (I'd be highly surprised if any team managed to even come close to maxing out the serial port) but I thought it was important to point out.

Matt

The Basic Stamp runs at quite higher than 40 Hz. It executes somewhere in the thousands (tens of thousands?) of PBasic instructions per second. These are a much higher level construct than assembly language so it executes even more instructions per second.

I believe the ~40 Hz number you produced came from the fact that the robot controller received input data approximately 40 times a second. Given that it blocked before reading data, it basically meant you went through your loop 40 times per second.

Matt

What exactly is a TTL serial port? What's the difference between it and a normal serial port?

I've been asking around and no one seems to know:confused:

This is mostly an educated guess but I'm assuming TTL Serial port means that the line level outputs of the serial port are at TTL level. TTL level defines zero as from 0 to 0.8 V and a one as from 2 to 5 V. Now, normal RS232 Serial Ports have an operating range from -15V to 15V for their output. The TTL Serial Port is a serial port that is specifically designed to interface with either TTL or TTL-compatible circuits. This means that it's much more effective for controlling a custom circuit than a regular RS232 Serial Port.

Matt

I agree with Matt. It would be an easy way to connect to a second PIC chip (if you want to use one for something else) and it would act just like an RS-232 link, expect you dont need the tranceivers to convert the voltage levels, since your second PIC chip will only be a few inches away from the robot controller.

This new robot controller is really going to open up a lot of possiblilites for teams with EE's and SW engineers to do some impressive stuff with the machines.

Finally, power real power. Now the programmers can take over the world.

Oh, sorry. I think I'm getting a little carried away:yikes:

Yeah, us mechanical guys have been asking you software guys to work your magic for years, but your excuse has always been "the processor is not fast enough!" or "we don't have enough memory!".

Now, you're gonna have to look for new excuses.

Have fun, bit-twiddlers!

:)

Andy B.

I predict many sleepless nights (not that anything will change, in that regard), lots of heads being banged on desks, datasheets and manuals scattered over the floor, and Mountain Dew / Jolt / [pick your poison] cases filling the garbage cans.

You know those Spark-Es... always SOMETHING to whine about.
;)

C Compilers?
 

Anyone know if the Edu kit includes the MPLAB-C18 C compiler? If anyone has experience with this or other compilers that will play nicely with MPLAB, would you share your recommendations? Looking at the Microchip recommended compilers, it looks like most are $450 or more per license, except the CCS one for $175 .

I believe each team will receive the Full MPLAB w/ C-18 and Innovation First's Programming Tool/Library for the RC with the pre-season kit. I already DL'd MPLAB... Tinkered around a little...
There's really not much to do until we get c18 and the Library file, or whatever addon innovation first supplies us with.

Also, Freeze!
I just noticed something...
The eduRC does not have team number dip switches on it!
Does this mean that the eduRC will respond to any control system in the area?
Or is IFI creating a new way of Identifying teams in the control system, Maybe through programming?
Perhaps the device has a small memory block set aside for holding the team number, and it must be defined in the header of the program?
Hmm...this is interesting.
I wonder if the full-size RC will be the same?

Also, the RC PWM-In looks like it is an input from the PWM outputs on the Main RC. I'm not entirely sure why.. but it seems like a cool idea. It really seems like they like the idea of interfacing the edubot with the main RC (TTL serial, Digital i/o, PWM in/out) I'm really beginning to think they may actually let us use the eduRC in collaboration w/ the full one this year...

How about the recycle bin? A little extra money for the team?

I seem to remember a certain Dr. trying to collect aluminum cans in New Hampshire to take back with him to Michigan to help fundraise for his team. Then again, I'm probably the only one who remembers that...

Matt

Heh, I like the guys optimism...

But illegal actions are kinda not-cool at the same time, and as much as I think that's awesome, it is also quite illegal because you rob 5 cents a can from the state... not that they shouldn't be supporting robotics, but maybe we should work on getting them to do it formally...

*Eyes glaze over with joy!*

one good reason to have a PWM input is you can design separate sensors or electronics that the RC uses as an input

and a PWM is a digital signal. Unlike the analog inputs, if its putting out zero, its putting out exactly zero, and the RC will read zero every time.

So the PWM input will lend itself to teams developing sensors (position, heading, yaw, speed, torque....) with a standard output.

That will allow the design to be used from one year to the next, and for teams to produce white papers on their designs that other teams can easily implement.

Also, I think there might be some sensors or gyro things on the market for radio controlled airplanes that have PWM outputs.

Good point. Or you could do like Dave Lavery, and forge your own prototyping material out of scrap aluminum and spare cans. Recycle, reduce, reuse, and close the loop!

Also, as an aside, I thought this was just funny, as the comic strip tends to be. But I thought it was very funny that it's written in C. :)

I saw that comic today in the papers because psychology deals with it (I dunno yet why/how).

Back on topic: I hope to God that they allow USB-port connection this year. Every laptop I've seen is only USB, and not RS-232 (or RS-232c).

USB ports?!

that means we cant buy our 'FIRST' laptops on ebay for $50 anymore!

give up my trusty ThinkPad with its screaming 133MHz processor, 40MB of ram and 1G hard disk?

NEVER!

[PS there is nothing in the spec for the new RC about USB ports]

If you think I'm saying "they are gonna let us use USB ports now!!! w00t!", then your wrong.

If not, then I know. I am just saying I hope that they do allow it. I discussed this w/ Brandon at Kettering and he feels the same way (I dunno if it really matters how anyone else feels, all well).

If you can afford a $1000 laptop then I'm sure you can afford a $40 USB-to-RS232 converter (here or here). Justify it as a general team expense.

There's no reason to increase IFI's cost and the complexity of a circuit to ditch a tried-and-true method of communication to implement USB. Microcontrollers don't understand USB signaling so an extra converter circuit/chip would be needed. Why would IFI do such a thing when it's pointless?

There are several microcontrollers available that support USB directly.

Also, those USB to serial converters aren't always that great. We tried using a few last year to program our custom circuit microcontroller and it was a no-go.

I never said I had a laptop, I just said that most laptops only have USB ports now.

Another scenario in which one should never assume anything.

I would definately reccomend learning C before PIC assembly. C is in practice much more robust and easier to use. If you know x86 asm, it shouldn't be hard to learn PIC asm, but i would concentrate on C.

Indeed, there are. :)

Hmm... Not only is there "PWM IN" but the "PWM outs" are 4 pin instead of 3pin. I wonder if they will not be using standard RC type interfaces for the speed controllers. Maybie you connect the plug between one set of pins for 2ms out and one way for 17ms out. This may or may not be possible depending on the pinout, but right now im too lazy to look it up.

Just about dead-on. TTL is short for Transistor-to-Transistor Logic. The PIC Processor has a USART capable of 2 separate serial communications, in addition to the master serial port.


I was one step ahead of you and checked into that. According to this site, the one's I listed have few compatibility problems.

Jnadke

I dont know what spec sheet you are looking at? The PIC chip that is in the new RC has 68 I/O ports (pins) - not 9

?!

http://www.microchip.com/1010/pline/...8520/index.htm

The PWM output on the EduRC have historically been 4 pin connectors. On last year's EduRC, two of the four pins were connected to Vcc. The motors used one supply for logic, and the other for powering the motor itself. I doubt this has changed. I'm willing to bet that there are a few specific PWM outputs which will be 2ms, and specific outputs which will be 17ms (say outputs 1-4 are 17ms, and 5-8 are 2ms, for instance).

Being as the 18F8520 has an onboard 16 channel, 10bit ADC, I would expect those inputs to go directly to the user programmable microcontroller on the EduRC, rather than having another arbitrary layer separating us from the data. On the FRC RC, however, this may not be the case, being as they have the inputs listed as 16 analog and 16 digital (in or out). I guess we'll have to wait a little longer for clarification on this.

Regarding interrupts, however, while I might be able to explain some, I am confused about something. You're correct in that there are 13 sources for interrupts, at two different user-selectable priority settings, on the controller, but there're only 4 external hardware interrupts available on the 18F8520, with the rest being software related (timer interrupts, USART Tx empty and Rx full interrupts, A->D conversion complete, etc.). INT[0-3] are pins 55-58 (in reverse order), so I am very curious as to how they're getting 6 external hardware interrupts.

I guess this all means that, despite IFI releasing so much information to the public, the answers they've given have only produced more and more questions.

Time will tell.

I completely missed the pin diagrams, I was looking for those. I read it and assumed that the IO Ports were serial, but that didn't make any sense. I see what it meant now, the individual pins are grouped into a single 8 bit register.

I've since removed my post/theory because the cached webpage from IFI. After I posted, I refreshed IFI's site and I noticed their specs had changed. One of the things that didn't make sense was that they listed I/O pins were sampled at 50 MHz.

It is very possible (and likely) that like in previous years' controllers there will be a master and a user programmable microcontroller. The user programmable controller sends commands to the Master processor, which generates PWM, Is in charge of auto/disable etc.

Anyone else notice that the EDU-RC doesn't have a tether to operator plug or switch?

What does that have to do with using it for programming an RC? That site just shows USB to serial compatibility with some piece of audio equipment. The USB to serial converters that we have work fine with most other things...

Did you notice that the indicator LED says PWM IN/RADIO?
Can we control this thing PWM inputs only?
Will the new OI have PWM OUT?
What is the deal with the PROG push button right next to the battery?

There are so many questions to be answered. I can't wait to so the Full RC, especially since my team will not get the EDUbot. I kind wish everyone got an EDUbot since this is a new controller, and it would be nice to have something to test the program on.

This is from the 9/26 FIRST email blast:

So once you pay, you should get it when they start shipping out, around 10/15. ;)

My understanding from what is on the IFI site is that returning teams from last year will get only the new EDU-RC, rather than the entire EDU kit again...