how to build a VEX programming module
 

After spending a good deal of time playing with the VEX kit and the people from Radio Shack over the past week, I'd like to try to build a cable to program the VEX microcontroller.

The board is basically the same as the IFI board that used to be dubbed "Isac" from what I hear. I'm not familiar with the IFI boards, but there's software out there to program them. From what I hear, that software can be used to program the VEX board. All you really need is the right pinout for the connector (and possibly a telephone chord with all 6 wires in it).

With a brief time using a DMM, I've found that the red telephone wire goes to the Vss pins of th the PIC chips. Other than that, there were no obvious (not run through a capacitor or resistor) connections to the pins of the PIC chip.

I'm sure that there's interest out there in producing this cable, so if anyone out there has any thoughts that would help, I'd really appreciate it. Thanks guys.

~Ben

Re: how to build a VEX programming module
 

I intend on getting a VEX kit in the near future, and as it is driven by two PIC microcontrollor chips, the ability to create our own periphials should be easy. I too will join you in the quest for unlocking the secrets of VEX.

Re: how to build a VEX programming module
 

I found that pins 1-3 are Tx1, Rx1, and Gnd, respectively, for UART 1 on the user uP. The only major difference between the Vex controller's serial port and that of the Edu controller is that there is no onboard TTL - RS232 converter. All I did to build a module is convert the TTL signals to RS232 signals with a MAX232 chip from TI and then use IFI Loader to communicate with the Vex controller. The other pins on the Vex's serial port are control lines RTS and CTS, and the actual line that puts the controller in program state (similar to what the program button does for the other IFI controllers. I used a 25' 6-conductor telethone cable from RadioShack (part #279-422) and then put a button on the module that will put the controller in program state.

Re: how to build a VEX programming module
 

I have a max 232 chip already from another project I am working on. It was my PDA Bot project that seems to just be kinda stuck in limbo. Perhaps I'll find a way to merge the two projects. The goal for PDA bot was to be able to feed it exact positions, and to use a gps, and onboard navigation sensors, to get to that position. Well, the ideas are growing and I am still unable to afford the kit (will take me about two weeks before i'll have enough). So, soon, very soon, I'll have the kit, and I will be building. Soon after that I should have the resources to have a VEX team started, and start teaching some kids.

Re: how to build a VEX programming module
 

Pinout for the Vex serial port is as follows:

1 - Tx for UART 1 on the user uP - White
2 - Rx for UART 1 on the user uP - Black
3 - Gnd - Red
4 - RB0 on the master uP - Green
5 - +5v - Yellow
6 - RJ3 on the master uP - Blue

Re: how to build a VEX programming module
 

Sweet, that'll save me some time. Good information to have.

Re: how to build a VEX programming module
 

If you don't mind, what pins did you use for the program button? I assume you tied either pin 4 or pin 6 to either ground or +5. Also, does the switch need to be a constant on/off or does it need a momentary switch similar to the "hotsync" button on a PalmOS pda?

I'm obviously not very familiar with the hardware, so I appreciate your help. Now that you have a working programmer, could you post a schematic of some sort?

~Ben

Additional realizations:
The color / pin number correlation depends on which end of the phone cord you're looking at. In the above pinout, looking at the end of the phone cable with the little springy catch on top, which side is the white wire?

Assuming pin one is on the left and is white, I'm also seeing +5v on pins 1, 4 and 6. Also, the "program" LED on my board is on. Is that normal?

Re: how to build a VEX programming module
 

Standard telco RJ11 Connectors use is as follows:
Working at at telco has a few perks after all.

Re: how to build a VEX programming module
 

Nice. However, that doesn't clear up whether the above pinout assumes pin one is white or blue...or more clearly whether pin one is to the left or right with the little catch mechanism at the top or bottom.

Regardless, it's nice to know what color actually lines up with what pin. Thanks!

~Ben

Re: how to build a VEX programming module
 

Has anyone put any kind of more simple howto tutorial on this up? Maybe with some pictures and the tools used? Also, has anayone tried figuring out the signals to send to Rx1 and Rx2 to control the robot? I'm not really too interested in programming the microcontroller. I'd just like to hook it up so that my laptop can control its movements and be notified of the interupts.

Re: how to build a VEX programming module
 

ok. i've gotten a 7 foot six conductor straight through rj11 cable from jameco, a max232 and a couple of jacks with wires hanging handily out the back, all for considerably less than the 25 foot monstrosity available at radio shack would have cost. 'til you factor in the shipping of course. but i would have had to order the max232 and the jacks anyway.

so here's my question. which pin does the program button use? i'm guessing rb3, since that port, assuming i've pulled up the right data sheet, can trigger interrupts. also i'm guessing i should connect the switch to ground since port b has internal pull ups.

another question might be has anyone figured out the function of the pin that connects to rj3?

lastly, has anyone got a clue about the api? is it too much to hope that libraries from the other ifi controllers, (with none of which have i any experience), would work?

well, that's it for now. time to hit the shower and head to work.

thanks.

Re: how to build a VEX programming module
 

thanks, fowlerm.

now i've got something to read this weekend.

just wondering... is it cool to distribute this code? haven't come across licensing information, yet.

Re: how to build a VEX programming module
 

ouch. should have checked out the cost of the compiler before i bought the robot.

let's see.

$299.00
+ $595.00
----------
$894.00

suddenly i don't feel so good. if the bite for the vex programming kit is going to be anything like this i can see why they released the hardware four months ahead of the development tools.

just for suckers like me.

Re: how to build a VEX programming module
 

You can use the Student Edition C18 compiler from Microchip which is free. The only difference is that the Extended Instuction set optimizations are disabled after 60 days, but the compiler is still completely functional with the standard PIC18 instruction set beyond the 60 day mark.

The download link to the Vex default code should be on vexlabs.com when it is released, or you can email info@innovationfirst.com to get it now if you really want it.

Re: how to build a VEX programming module
 

Thanks, that's a big help.
The starter kit is a little underwhelming without programming capability

Re: how to build a VEX programming module
 

i sent an email to info@ etc. the other day and the word was that the default code would be posted on vexlabs.com next week and that programming kit prototypes would be available as well at that time.

Re: how to build a VEX programming module
 

the default code has been released!! You can find it here

This also contains the ifi loader you will need, but no luck on the prototype programming modules.......

Have fun!

Re: how to build a VEX programming module
 

What is the REV on your VEX board? I am not finding the pinouts like you described. I find that

1- RB1 (master)
2- RJ3 (master)
3- GND
4- C1OUT
5- +5v
6- can't find where it traces to yet

My VEX board has this printed on it:
RS-TALOS
REV NC3

This is on the serial port and not the RX1 or RX2 ports.

Thanks,
Bronson

Re: how to build a VEX programming module
 

Does anyone know what the 'default' program module will contain? Does it come in both USB and rs232 port versions? Losts of laptops today don't have serial ports.

Re: how to build a VEX programming module
 

The programming "cable" that will be shipped contains the level converter for serial ports. The idea of the extra hardware is to make it more immune to serial port and laptop performance differences. The original IFI controllers were very sensitive to laptop speeds and USB-serial adapters and would often fail loading the program.

Brad

Re: how to build a VEX programming module
 

fired up the ohm meter this morning and my results confirm fowlerm's.

my board is also labeled rs-talos rev nc3.

note that the master and user controllers are not oriented the same way on the board and that the c1out, (pin 18), is 90 degrees away orientation-wise, from tx2, (pin 38).

to test i plugged a straight through 6 pin cable into the programming port and a jack with wires hanging loose, then connected my ohm meter to the various wires at one end and to pins on the chips at the other. the wire colors i got are the same as reported by fowlerm.

furthermore, with the board powered up i read 4.9 volts on rb0, (green). this pin has an internal pullup, so i assume that that's appropriate, and that connecting a switch between rb0 and ground will generate and interrupt on the master controller.

haven't managed to get a cable working but, hey, i'm in way over my head.

good luck.

Re: how to build a VEX programming module
 

Supposedly there will be two versions of the programming module, one that has a RS-232 to TTL converter and the other will have a USB to TTL converter, but I haven't been able to confirm this.

Re: how to build a VEX programming module
 

I spoke with someone at vexlabs today, the prototype boards are available and so far, no one has purchased one. They are around $100 for the prototype board. He indicated that the program kit at radio Shack will be around $130. I asked if it was just a level converter and he indicated that is has an actual pic processor on it. He also indicated that the two chips have a boot loader for loading code. Both chips will be update-able via the loader. I was thinking about returning my system, but after finding out that the controller is PIC based and that I would update the code on the chips, I plan on keeping the system. BTW... The processors on the board are PIC 18F8520. Has anyone researched if the In circuit programming pins are available on the connectors. This may be a quick way to update the code on the controller.

Re: how to build a VEX programming module
 

All in due time folks.. All in due time. :cool:
Looks promising though, and easy to use.

Re: how to build a VEX programming module
 

The PIC's ICSP pins are not available through the 6-pin connector. The bootloader that's on the chips is a serial bootloader that uses the PIC's USART to download code and write to the program memory. If you use the ICSP pins to download code you have to have a hardware programmer like the ICD2, but if you download the code using the bootloader all you need to have is serial port on a PC and an RS-232 to TTL converter.

Re: how to build a VEX programming module
 

Were you able to actually program the module, if so,
did you use the same compiler for FIRST,

Do you have any example programs that you wrote,
Also, has anyone found a schematic of the vex kit,

thanks

~Andrew Lynch

Re: how to build a VEX programming module
 

I got the VEX kit for my birthday, and as the programmer on my team, I badly want to program it.
I bought a couple of MAX232 chips, and I have some RJ11 and DB9 cables.
The datasheet for the MAX232 says that it inverts the logic, so do I need to invert it back to normal?
Thanks,
Steven

Re: how to build a VEX programming module
 

The programming module has a PIC and does not include just a converter interface. Contact vex labs to obtain a programming module.

~Andrew

Re: how to build a VEX programming module
 

after spending last weekend fruitlessly trying to put together a programmer with a max232, a handful of capacitors and a momentary switch i gave up and ordered a prototype programmer from vexlabs on monday.

it arrived today and in addition to a level shifting ic there is a microchip 12f629 on board. boy do i feel like a dope...

Re: how to build a VEX programming module
 

Ok, so maybe there's more to it than you thought. but my hat's off to you. Those efforts which seemed futile will someday pay off in other ways, although you may not see it now. Even if only 1 out of 4 things you try work,that's better than most folks' 0 for 0, not to mention what you would learn in the 3 "failures." Yours is the path to accomplishment.

(BTW, my programmer module arrived Thursday, but I haven't had the chance to try it out yet!)

Re: how to build a VEX programming module
 

Where are you ordering your modules from? I can't find it online.

Re: how to build a VEX programming module
 

send an email to info@vexlabs.com with your address and a daytime telephone number and tell them you wish to buy a prototype programmer. i did this last week on monday morning, received a call a couple of hours later, gave them my credit card info and had the board in my hot little hands friday afternoon. what you will receive is a small board with an rs232 level converter and an 8 pin pic microcontroller, an rj-11 connector at one end and a db9 connector at the other. they include an rs-232 cable, a 6 conductor phone cord and the c-bot disk, (mplab, mcc18 and ifloader), that is apparently used in first programming. what you don't get is a pretty plastic cover for the programmer and the visual programming environment.

alas, i'm still trying to locate a driver for my usb to serial converter.

oh, yeah, $99.00 plus about $8.00 for the ups guy.

Re: how to build a VEX programming module
 

The work done to make a programmer is not wasted, Think about having multiple vex controllers or a laptop commanding the vex controller (similar to the botball GameBoy Xport)

Therefore a converter from Db9 -12V to +12V (CMOS) with a max232 converting to 0-5V TTL Phone Jack to the Serial Port is very useful.

According to the Vex people (IFI) , everything with Kevin Watson's serial driver should work similar to the FIRST controller. Therefore, if someone could establish basic serial communication with the controller, new inventions are bound to come.

~Andrew Lynch

Re: how to build a VEX programming module
 

The VEX programming module will be available in August 2005. You can check out other VEX products or connect with other VEX users at www.vexrobotics.com

Re: how to build a VEX programming module
 

thanks for the pinout , but still i don't know which is RTC and which is CTS ?

another thing is i will connect a bluetooth module to the microcontroller and i will connect it to the serial of the microcontroller , so i know which pins to connect on both except for the +5v on the microcontroller , does it mean that i will get external voltage source ( 5v ) and connect it to pin 5 and not connecting the batteries to the microcontroller ?

thx fowlerm for the useful info .

if anyone wants to take a look at the bluetooth module i'm connecting ,, here it is BlueTooth v1.2 Stamp Module Data Sheet

Re: how to build a VEX programming module
 

rtc and cts are not connected. the serial interface is three wires only, tx, rx and ground. you'll need the +5v to power the bluetooth. if you're trying to build a programmer, you may not have much luck. i tried using a max232, a handful of capacitors and a push button and couldn't get anything going. the programmer that vexlabs is selling has an 8 pin pic on it. if you just want bluetooth for serial coms between a pc and the robot you ought to be okay. probably just need to remember to cross rx and tx.

good luck.

Re: how to build a VEX programming module
 

u mean get external voltage source and connect it to pin 5 of the serial input to power the bluetooth module ? Or this pin is an output 5v pin which must be connected to the VDD pin of the bluetooth module ?
this is strange , because the bluetooth has it's voltage input pin which takes 3.3v so i don't think this 5v pin is for the module .

something else about RTS and CTS ... fowlerm posted : " The other pins on the Vex's serial port are control lines RTS and CTS "
so if pin 4 and pin 6 are not rts and cts , then what are they ? and where should i connect the rts and cts of my module ?

Note : i just want bluetooth for serial coms between a pc and the robot

Re: how to build a VEX programming module
 

I've been using this Bluetooth module with success.

-Kevin

Re: how to build a VEX programming module
 

That was my initial thought, I now know that the following pinout is correct:

1 - RJ3 on the master uP
2 - +5v
3 - RB0 the master uP
4 - Gnd
5 - Rx for UART 1 on the user uP
6 - Tx for UART 1 on the user uP

The numbers correspond to the numbers printed on the Vex Controller's PCB.

As far as RTS and CTS for your module, they are only used for hardware flow control. If you don't want hardware flow control I believe you can simply connect the RTS pin to the CTS pin to have the module operate without flow control. I know this is true for the module Kevin Watson posted.

Re: how to build a VEX programming module
 

ok thx fowlerm for the useful info again .

so now i will not use cts and rts , and i will ignore the rb0 and rj3 pins on the serial of the microcontroller .
one last thing remaining is the +5v pin on the serial of the microcontroller , shall i connect this pin to the voltage input pin of the bluetooth module ? or shall i connect external voltage source ( 5v ) to this pin ?

Re: how to build a VEX programming module
 

Has anyone figured out what the PIC on the programming module does? If it's in a socket, maybe someone can put it in a standalone programmer and find out if the code is read protected. If it's not read protected, then we should be able to figure out what it is very quickly.

Or maybe someone can put up a schematic of the module and we can make an educated guess about what it does.

I'd do it myself, but I don't have access to one. Actually...someone on our team was assigned to figure out how to program the thing, so maybe we do have one...

Re: how to build a VEX programming module
 

it's a wee little surface mount thingy so small that i needed a magnifying glass and had to hold it just so to the light in order to be able to tell that it was a pic at all. this puppy will never be socketed.

if one had enough serial ports one could watch what goes in and compare it to what goes out. i figure the button just causes the master controller on the vex to reset the user controller and kick it into a bootloader. can't imagine what goes on that would require another pic in the middle unless it's just a form of obfuscation to confuse things enough so radio shack can sell us programmers.

Re: how to build a VEX programming module
 

aaaaaaaaaa! I tried to order a prototype module, but 1, they don't have any for usb, and 2 they don't work with macs. I have a powerbook that i bought with the robot to hook up to control the robot. Now I feel like I wasted 300 bucks on a fancy modifiable remote controlled car. They should really consider the possibility of people wanting to control the robot with laptops or linux boards. This i think would produce an even greater market for radioshack. I thought it was a handy device that would take care of all the motor and sensor controls easily for me. Help me out. Is there a way i can get this to work without the programming module? Does anyone really have a working module that they made? And do you think it would work for mac osx?

Re: how to build a VEX programming module
 

you're really going to need a windows system, or a linux box running wine, because the compiler is windows only. i run linux most of the time, but have a windows partition on my laptop where i've installed mplab, mcc18 and the ifiloader. i run the programmer through a usb to serial converter that cost around 20 bucks. tried to build a programmer myself, but gave up and got the prototype from vexlabs. there's a little pic on the programmer in addition to the rs232 level converter you'd expect. like i said, works great, except for the $99 hole in my wallet and that i have to boot windows to run the compiler.

Re: how to build a VEX programming module
 

Well i also have a desctop PC. Perhapse I can program the robot with the PC and control it with my powerbook later? I have a usb to serial converter that works for both PC and mac. I think that's what i'll end up doing. I have an m232 converter, so i think i could send signals to the serial port with the powerbook if I program the the controller to read from the serial port. Otherwise I was wondering if I could change the rx1 and 2 ports to read a serial signal instead of the PWM signal it is currently programmed to read. Anyone done anything with this or have any comments?

Re: how to build a VEX programming module
 

unless you want to bitbang it, forget using rx1 and rx2 as serial ports. the 18f8520 has two hardware usarts. one is the programming port and the other is available as the rx and tx pins at the top of the analog/digital section on the controller. note that these two pins cannot be used for analog input, but can be configured either for digital i/o or for serial i/o. to use either port to talk to a laptop you will need to convert the ttl signal levels to rs232.

Re: how to build a VEX programming module
 

allow me to correct myself... rx1 and rx2 are connected to the master 18f8520, so you don't have access to them at all. all the master does is listen on rx1 and rx2 and decode the incoming pwm then send the information via the spi bus to the user controller which is the one you can actually program. i think it probably also resets the user controller and kicks it into the serial bootloader when the program button on the programming module is pushed.

by the way, radio shack announced pricing on their programming module and it's the same $99 as the prototype from ifi but will include easyc, so if you can stand to wait a month or so...

in other news, my laptop decided to die yesterday for my 51st birthday so i'm now without a windows box to program my kit. guess it's time to knuckle done and learn to run wine.

Re: how to build a VEX programming module
 

For those of you wondering, the USB to serial driver for the Vex programming modules (which will work with both prototypes and the commercial version) comes with the install of the EasyC software. EasyC software will come with the commercial version of the Vex programming kit. I don't know if it will be available stand-alone.

BTW, the EasyC software's name really means it. A little over 12 hours ago I knew nothing about C, but in less than a few hours, I had been able to program a VEXbot with the Vex Ultrasonic sensor to navigate the room avoiding obstacles. :D

Re: how to build a VEX programming module
 

actually what i'm wondering is where you're getting this stuff. where are you getting this stuff?

Re: how to build a VEX programming module
 

Can't...reveal...sources... Top...secret...information...

Just kidding. ;)

Actually, I'm at the WPI summer Frontiers Program in their robotics course. WPI has helped beta-test the Vex line, and we are using these parts in a mini-Vex competition. Word on the streets is that FIRST may be paying attention to our mini-competition, as they would like to see how to incorperate certain details into future Vex Competions. :cool:

Re: how to build a VEX programming module
 

So has anyone managed to figure out how to make a bootleg programmer yet? I'm not really interested in building one myself, just curious.

Re: how to build a VEX programming module
 

i need that easyC to program the microcontroller plzzzzzzzzzzzzzzzzzzzzz
i got the prototype programming module but i dont' understand C so that's a major problem and untill now i cannot program the microcontroller .
i got a bluetooth module and connected it via serial to the microcontroller so i could control it through my pc , and the bluetooth works fine with the microcontroller except that i need to program the microcontrollerrrrrrrrrrr.
HELPPPPPPPPP !!!!!!!!!!

Re: how to build a VEX programming module
 

Sorry, but your only options are to buy the Vex Programming Module or learn C programming. As stated in the ChiefDelphi Rules, using these forums to try to obtain pirated software is illegal. Anyway, learning at least simple C programming is helpful when using EasyC, as it will allow you to use the software to its full potential.

I would reccomend purchasing the Vex Programming Module to get EasyC. Using EasyC is a great program used to learn C programming. You can drag-and-drop tha commands, or you can insert 'Custom Code' blocks, in which you can write your C code by hand. Also, the EasyC interface allows you to see the graphical code blocks and the actual C code at the same time, which would also help one learn C programming better.

Re: how to build a VEX programming module
 

EasyC is out...you can now get it at your local Radioshack or online!!


http://www.radioshack.com/product.as...Fid=276%2D2152

Re: how to build a VEX programming module
 

i got a bluetooth module and connect it to the serial input of the microcontroller , but i have a software that can program the microcontroller but not through serial input ,
so is it possible to connect the bluetooth module to the serial input of ??

Re: how to build a VEX programming module
 

I'm interested in programming my VEX microcontroller, but I don't want to pay the high price of $100. Does anyone have a circuit diagram they could give me to build the cable? Also, is there anywhere (other than through the $100 VEX programming kit) I could purchase the software components needed to program the microcontroller?

Thanks,

Jason

Re: how to build a VEX programming module
 

As much as you would probably like to try to build your own VEX Programming Module, it is illegal to share proprietary information - such as the circuit diagram of the module - or the actual signal signal coming out of the transmitter.

If you really want, you can make your own, but you would have to find another way to do it. If you really want to try to build a wireless (or Bluetooth or something entirely different) programming module, go right ahead. But remember, people protect their ideas with patents for a reason, so posting proprietary information is illegal.

My adivce is that you might as well buy the $99 programming module. That way, you will get the software you need to program the Vex Controller with it too. I have bought two Vex Programming Modules, one for my desktop computer, and a second one for my new laptop, so that I legally own two licenses.

Re: how to build a VEX programming module
 

How do I place the Vex controller into program mode?

I have already tried shorting RB0 and RJ3 to GND, with no results on the Program LED.

Someone with a working programmer: When does the Program LED turn on? Does it turn on as soon as you press the Program button?

Thanks!

Eldarion

Re: how to build a VEX programming module
 

Just so you guys know you can buy easyC V2 from shop.intelitek.com. You don't need to purchase the programmer.

Re: how to build a VEX programming module
 

If I remember correctly, you have to send it the right pulse train. That's not easy to do without some sort of active device. A high-quality voltage level-shifter can preserve the pattern produced by a computer's serial port and send the right info to the microcontroller; but computers' USB outputs and USB-to-Serial convertors are a crap shoot. Hence the valuable little circuits inside that Vex box that converts USB into TTL-level serial.

Blake
PS: Using a computer's serial port to drive only a level shifter (not using the computer's USB port) let's you download code much faster (around 2X?) than going the USB route. However, some modern PC's don't even have serial output ports...

Re: how to build a VEX programming module
 

I finally got it into programming mode by connecting the RTS/CTS signals to the serial port through a MAX232 converter. When I run a "Controller Verification" in the IFI loader, it thinks it is talking to an FRC controller ("Controller Verification Complete..." and "FRC" a little further to the right.)

However, when I try to actually download code, it goes through the CTS/RTS handshake, starts the Program LED blinking, and asks me to hit the (nonexistent) "Program" button on the FRC controller. An analysis with PortMon reveals that the IFI loader is sending six periods to the Vex controller, and expecting some kind of response. The Vex does not send any response, and the download fails.

Does anyone have any ideas on this? I am sooo close... :D

If I can get it working, I will be posting some kind of schematic and/or tutorial on how to build one of these things!

Thanks,

Eldarion

Re: how to build a VEX programming module
 

One idea that i have come across while at work at Microchip is the idea of trying to use a Microchip PicKit2 Programing module, heres the link to it PICKIT2

.. njust an idea

Re: how to build a VEX programming module
 

You can use an in-circuit debugger to program both the master and user processors. You have to open the case to access the connector.

Using the pin designators on the silkscreen of the pc board, here is the pinout:

J1-17 PGD on the Master Processor
J1-18 MCLR on the Master Processor
J1-19 +5v
J1-20 no connect
J1-21 Port B7 and PGD on the User Processor
J1-22 MCLR on the User Processor
J1-23 RX2 on the Master Processor
J1-24 GND
J2-9 PGC on the Master Processor
J2-10 GND
J2-11 Port B6 and PGC on the User processor
J2-12 TX2 on the Master Processor

Re: how to build a VEX programming module
 

After following the directions posted previously in this thread, I managed to build a working programming cable. When using a usb-to-serial converter cable, they somehow mess up the handshaking that is going on to put the Vex microcontroller into programming mode. So to fix that, I had to use a microcontroller to generate the correct signal. So my home made programming module has a microcontroller in addition the the RS232 level shifter. You can take a look at the cable and a video of how it works on my site: www.CrestOak.com. Enjoy!

Re: how to build a VEX programming module
 

Please can anyone share their working circuit diagram on how to interface the max232.

One thing that really puzzles me is where and how to connect the program button.

Thanks.

You can also email me at n0rad2002@yahoo.com.sg

Cheers

Re: how to build a VEX programming module
 

Do you plan on sharing the schematic and source for your cable?

Re: how to build a VEX programming module
 

Unfortunately, at this time I don't plan on releasing the schematic and source. Right now I'm hoping to use up some of the extra parts I have in making complete cables. However, after that, I might spend the time to create a readable schematic and release the code.

Re: how to build a VEX programming module
 

Does the module put the controller into programming mode using the control lines?

Re: how to build a VEX programming module
 

Apparently so, but I'm not sure exactly how yet. Can someone explain what the handshake combination is?

I bought my son a VEX kit over the holidays, and wrote a VEX loader for *nix shortly afterward.

I made a serendipitous discovery that Mac OS X and Linux trigger programming mode by accident when the port is closed. (FreeBSD does not.) This happens reliably with both the USB/serial adapter and with a direct connection to the serial port on Linux. I'm using the orange programming module that came with the EasyC kit.

I can prevent it from happening by dropping RTS using an ioctl() call before the port is closed. Apparently OS X and Linux drop RTS when the port is closed, and this is *part* of the handshake to trigger programming mode. I have tried various combinations of dropping and raising RTS and other control lines, with no success turning on programming mode.

Thanks,

Jason

Re: how to build a VEX programming module
 

You just need to plug the RTS and CTS into a serial cable that plugs into the computer to successfully complete the handshake.

PIN_LAYOUT

Re: how to build a VEX programming module
 

Now if I have a rs232 to TTL converter that has the following pinouts:

GND
RX->
TX<-
VCC 3-5v

and I'm using a real RS232 pc port. Where do I Connect pins 4-CTS & 6-RTS from the vex programming port? The TTL converter does not have these...

Do I connect them directly to the serial port ? Does the TTL converter only need the TX/RX ports to go through it?

I dont use a USB to RS232.

thanks

Re: how to build a VEX programming module
 

What a useless and deceptive thread in regards to this programing button & cable. Funny thing is there is already a poster above selling this so called "Proprietary" cable for profit.. Way to go protecting the cable secret bs!

Re: how to build a VEX programming module
 

Normally, I try to avoid this sort of post, but this one kind of set me off:

1) The thread includes the information you would need to make your own VEX programming cable. I don't think anyone is trying to be deceptive.

2) What cable secret? If you want to buy a factory-made and -supported part you can do so from IFI, and if you want to make your own, you can follow the information here.

There are better ways to communicate than through invective and imprecision. Perhaps you can more fully explain what you are trying to say?

Re: how to build a VEX programming module
 

ya i know bringing back a dead thread
but can someone post some detail easy to understand pictures of how to make the VEX programming module please.
i will use USB to Serial Cable, RJ14 6-pin cable

Re: how to build a VEX programming module
 

Based on what has been written earlier in this thread, the answer is almost certainly "No".

PS: It's not a dead thread - Don't let bullies convince you that tapping into existing information instead of splattering the net with constant ill-informed chatter is a bad thing. "Those who don't know history are destined to repeat it."

Re: how to build a VEX programming module
 

ya i know that but we cant afford the vex kit and we are going to nationals soon

Re: how to build a VEX programming module
 

Vex Nationals is in about 10 months.

Re: how to build a VEX programming module
 

Wherever you are going and whenever you are going there, building one of these isn't something you just sit down and do overnight.

Borrow one from someone/somewhere, or buy an inexpensive used one from eBay. Either of those will be far easier than building one from scratch.

Blake
PS: Which national competition are you headed to? TSA, BEST, The Create Foundation's tournament? something for PLTW? something else?

Re: how to build a VEX programming module
 

Hi Guys,

I have an extremely cheap VEX robotics kit for sale. It includes the programming device. I am going off to school and don't need the kit anymore, and I know that maybe one you guys may need some parts for the competition.
Here's the link:

http://cgi.ebay.com/Vex-Robotics-Dua...#ht_500wt_1156

Thank you and enjoy!