Cutdown IOx - minimum features.

If you have ideas for a new board, for new features for existing boards, or want to suggest new applications for the I/O Extender, this is the place to post.

Cutdown IOx - minimum features.

Postby Rod S » Wed Mar 30, 2011 1:16 pm

As per my post in the IOx section of the forum regarding the 14point7 modules, I would like a much smaller board that will deal with the inputs (I*x) and not too many of the the outputs (*Ox) :D

The best part of the IOx as I see it is the CanBus link to MS2/3 so accessing all the virtual ports, and the fact it accepts I2C inputs and the fact it can take Innovate's serial data if you add a RS232 chip.

I would like to access all those virtual ports by I2C (which I can with the current IOx), also USB (Jean's other proposed interface), have the RS232 option on the board, and leave the other hardware to myself to put on a custom PCB or veroboard.

ie, just the input functionality of the IOx board but in a much smaller size.

I hope that makes sense and would anyone else like to comment ???
Rod S
 
Posts: 301
Joined: Mon Sep 06, 2010 4:03 am
Location: Rural Suffolk, England, UK

Re: Cutdown IOx - minimum features.

Postby jbelanger » Wed Mar 30, 2011 1:21 pm

I have been thinking about it and what could be done is to basically have a CPU module that would include the CPU, 5V supply and CAN transceiver. It would have the same header configuration as the current IOx board so it could be used with the logger and SLC carrier boards as well as any custom board. I would also probably do a few other boards to make use if it.

That would not address Rod's requirement for USB and RS232 but those can be done rather easily on a custom board either by adding the circuits or by using readily available modules such as those from Sparkfun. The reason for not adding those to my proposed board is that I can see some cases where people would want 2 RS232 or none at all (direct TTL connection).

So that looks like the best alternative I can think of at this time that would allow all the flexibility and the smallest footprint. It also has the advantage from my point of view of allowing the use of the currently available boards but in a different way. And using the same CPU and header configuration means that the exact same code can be used and avoid any confusion on this.

Jean
Image
jbelanger
 
Posts: 3545
Joined: Sat Oct 03, 2009 12:24 pm
Location: Quebec, Canada

Re: Cutdown IOx - minimum features.

Postby Rod S » Thu Mar 31, 2011 7:01 am

Jean,

Thanks for the reply.

I take your point about RS232 - unfortunately we don't have an equivilant to Sparkfun in the UK, but making an RS232 circuit on a bit of veroboard (or custom PCB) isn't hard as the key componets are still available as 0.1" pitch discretes - but USB isn't so easy as all the chips I can find are SMD.

Personally I think USB would be worth adding.

I know you have a USB/CAN convertor planned - any updates on availability ??? - and your logger board has it installed, I just think it would be a key component to a small IO board that just dealt with communications.

But I'm probably going to be the only one who thinks so.... :(

Rod.
Rod S
 
Posts: 301
Joined: Mon Sep 06, 2010 4:03 am
Location: Rural Suffolk, England, UK

Re: Cutdown IOx - minimum features.

Postby jbelanger » Thu Mar 31, 2011 9:20 am

Actually, the Sparfun products are available from distributors in Europe: http://www.sparkfun.com/distributors. And from a quick look at one UK distributor, the prices don't look too bad. So that is still an option.

And the USB-CAN is coming but I have to solve some bugs in the MS2/Extra CAN code before I can fully test the code on the USB-CAN board.

Jean
Image
jbelanger
 
Posts: 3545
Joined: Sat Oct 03, 2009 12:24 pm
Location: Quebec, Canada

Re: Cutdown IOx - minimum features.

Postby UnaClocker » Thu Mar 31, 2011 10:41 pm

I think this might be the right place to mention this.. Regarding a USB-CAN adapter.. There's an Atmel CPU, 90USB1286, it's a Native USB device, so it can talk to the PC at full USB 1.1 bandwidth, 1.1mbit (or is it 11? eh, it's faster than any serial connection). If you were to use that CPU, along with a CAN transceiver, you could potentially do what I've always wanted, which is to get more bandwidth between the MS and all it's CAN devices, and TunerStudio. I'm sure Phil would be open to making TunerStudio do whatever it needs to do to talk to the new interface.. I picture setting up the Atmel CPU to come up as a USB-ethernet adapter, and then just tell TS to connect to the correct IP #..
And that Atmel chip is cheap, Digikey has them in stock, and listed at just under $11 each.. If you wanted to buy one to play with, check out a board called the "Teensy++", it's $24 and breaks out all of the CPU pins.. I have one controlling a little toy robot I put together.
Anyways, Whatcha think Jean?
'84 Dodge Rampage - MS3
UnaClocker
 
Posts: 165
Joined: Mon Oct 12, 2009 12:10 pm

Re: Cutdown IOx - minimum features.

Postby jbelanger » Fri Apr 01, 2011 12:20 am

UnaClocker wrote:I think this might be the right place to mention this.. Regarding a USB-CAN adapter.. There's an Atmel CPU, 90USB1286, it's a Native USB device, so it can talk to the PC at full USB 1.1 bandwidth, 1.1mbit (or is it 11? eh, it's faster than any serial connection). If you were to use that CPU, along with a CAN transceiver, you could potentially do what I've always wanted, which is to get more bandwidth between the MS and all it's CAN devices, and TunerStudio. I'm sure Phil would be open to making TunerStudio do whatever it needs to do to talk to the new interface.. I picture setting up the Atmel CPU to come up as a USB-ethernet adapter, and then just tell TS to connect to the correct IP #..
And that Atmel chip is cheap, Digikey has them in stock, and listed at just under $11 each.. If you wanted to buy one to play with, check out a board called the "Teensy++", it's $24 and breaks out all of the CPU pins.. I have one controlling a little toy robot I put together.
Anyways, Whatcha think Jean?

The USB-CAN adapter I'm doing will already do 500kbps or even 1.5Mbps. In any case the MS CAN bus is limited to 500kbps. And I have already contacted Phil about supporting the higher rates. But until support for the higher rates is there it will be limited to 115200 baud. The advantage of using the FTDI chip is that drivers are easily available for the different OSs and are quite reliable. And they are supposed to be usable from java.

Jean
Image
jbelanger
 
Posts: 3545
Joined: Sat Oct 03, 2009 12:24 pm
Location: Quebec, Canada

Re: Cutdown IOx - minimum features.

Postby UnaClocker » Fri Apr 01, 2011 1:16 am

Ahh, ok.. So it'll be like 500,000 baud, serial? The MS3 uses the FTDI as well, could that one be cranked up to 500,000 as well?
'84 Dodge Rampage - MS3
UnaClocker
 
Posts: 165
Joined: Mon Oct 12, 2009 12:10 pm

Re: Cutdown IOx - minimum features.

Postby jbelanger » Fri Apr 01, 2011 9:03 am

It could. It's just a question of coding it.

But that would also mean an interrupt every 20 microsecond. That's a lot for communication and could have an impact on other more important things. Using a USB-CAN adapter, the hit is taken by the adapter which is only doing that and when using CAN you have fewer interrupts because every CAN packets carries up to 8 bytes. So you have even fewer interrupts than with serial comm at 115200 baud.

Jean
Image
jbelanger
 
Posts: 3545
Joined: Sat Oct 03, 2009 12:24 pm
Location: Quebec, Canada

Re: Cutdown IOx - minimum features.

Postby Rod S » Fri Apr 01, 2011 10:28 am

jbelanger wrote:Actually, the Sparfun products are available from distributors in Europe: http://www.sparkfun.com/distributors. And from a quick look at one UK distributor, the prices don't look too bad. So that is still an option.


This is quite a bit off topic but as it started here.......

I've found the UK distributors, only a couple stock the USB convertor but that's better than none :D

1 - Ive found Sparkfun make at least three (maybe more but I found three easily) using either an FT232RL, CP2012 or CP2013 chip. Is there any preference ???

2 - presumably this gets hooked to RXD1 and TXD1 on JP2 as the other serial port is now hooked to an RS232 chip for the Innovate link. Thought I'd better ask before I blow it up :D

Rod.
Rod S
 
Posts: 301
Joined: Mon Sep 06, 2010 4:03 am
Location: Rural Suffolk, England, UK

Re: Cutdown IOx - minimum features.

Postby jbelanger » Fri Apr 01, 2011 10:45 am

I use the FT232RL chip (and so does the MS3) and there are good drivers for all platforms. I don't know about the CP201x chips but the boards are significantly more expensive.

And yes you connect to RXD1 and TXD1 on JP2. And make sure the USB board you use is configured for 5V I/Os which is not the default for the FTDI board.

Jean
Image
jbelanger
 
Posts: 3545
Joined: Sat Oct 03, 2009 12:24 pm
Location: Quebec, Canada


Return to Wish List & Requests

Who is online

Users browsing this forum: No registered users and 1 guest

cron