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Multi question on Spider config (SD Card, Touch)


#1

Hello!

Still a newbie, but gaining experience - anyway, this may be obvious (I hope) to some of
you but to me, as I’m not a EE person, not so sure -

Anyway, I have a project where I will need a lot of i/o’s and am using several modules
(usb-serial, T35 display, dual power usb, etc).

  1. I currently use and extender module on socket 9 and then use pin 5 for AO and gnd.
    I want to also plug in the SD Card in the open socket on the extender board, so that I’m
    using the SD + pin 5 for a separate Analog out. I looked at the SD module in the catalog but am not sure if it wants to use pin 5 or not (How would I tell). Anyway, will this work ok?
    I am allowed to configure it in the software but haven’t tried to run yet (as I don’t have an sd card to put in yet).

  2. for something completely different, I also wonder can I use the T35 display w/o plugging into socket 10? I want to use the analog In on socket 10 and am thinking socket 10 only
    applies to the touch screen which I don’t need but still need the display to work so would
    plug the display into the other 3 sockets (12,13,14). Wanted to ask this w/o trying it cause don’t want to destroy anything…

thanks!


#2

I guess on question 2 about the display, I could just select the N7 display instead
of the touch screen (but I already have the T35 at my desk, so would be nice to know
if I can use it as described above…).


#3

@ dave001 -

  1. All available pins are consumed by the SD module

  2. Pins 3,4 and 5 are available to use as Analog (since the socket also has an A socket type) but you will need to initialize the display outside of gadgeteer designer:

Display_T35 disp = new Display_T35(12, 13, 14);


#4

ok James, thanks for your quick response -

David


#5

@ dave001 - some useful references:

sockets and pin usage: https://www.ghielectronics.com/docs/120/gadgeteering-hardware#1132

guide to looking up information: https://www.ghielectronics.com/docs/275/where-and-how-to-find-information-and-help


#6

Thanks Jeff,

I had seen some of that type of info before, but would I have been able to answer my question using that info?

For example, I was wondering which pins the actual SD module used.
I know you can plug it in a type Y module, but couldn’t tell if that SD module actually
used pin 5 or not and was hoping to use that pin for AO.

I guess I would need to click on a module from the catalog and then see which pins it uses
but don’t see that is possible.

Or - maybe I have to assume that any module plugged into a socket will by definition use
up all the pins?? (I was thinking to use some unused pins via the extender, etc…)

Maybe your links give that info somewhere - I confess I only glanced through them for now.

anyway, thanks for the links! -
I will go through those in more detail, but for now my question
was answered as James indicated the SD card uses all the i/o’s.


#7

Hello again, sorry to beat this dead horse, but I realized there is a mistake.

I kept saying the SD module for socket of Y type but that is wrong, it can only go
in an F type socket.

I was confused because from visual studio, if you pull an SD module from the toolbox,
it will let you connect to the extender, even though the extender is on socket 9 which
does not have F as one of its types.

So, you have no choice but to use the SD module on socket 5, so my original question
was a mute point.

There is apparently a bug in the software as it shows it is ok to connect a module via
the extender to the wrong socket type.

anyway, just posting this to correct wrong info in previous posts/questions…

David


#8

Fundamentally, the extender module is only meant to be used to extend the cable. It is NOT meant to be used to “steal” unused pins. In the latest releases of Gadgeteer there was the ability to have multiple modules “downstream” of other modules (more than DaisyLink modules, that used to be the only ones that were permitted to do that) and perhaps that has now permitted the Extender to be used in this way.

If I wanted to achieve the use of any unused pins, from the designer I would NOT put the extender in the diagram, I would connect the device directly to the mainboard (as expected) and when connecting things physically I’d insert the extender in the chain. To make sure the pins I wanted to use were available, I would always use three resources. First, I would use the socket definition page to verify the pin I wanted to use was a GPIO pin, not a dedicated function pin (in your case, looking at the F socket would show that the pins are all used for SD specific functions except pin 3). I’d then look at the schematics of the module in question, where you’d find that pin 3 is used as a card detect IO, so then I’d not need to go to the 3rd reference which is the Gadgeteer driver on codeplex, where I’d be looking at pin mapping to make sure that a pin, while electrically connected, was or was not reserved/used in the driver. If all those came up clean, then I would be comfortable I could use the Extender to extract the usable pin for another purpose.


#9

Ok, thanks Brett, I understand what you’re saying. I should have spent more time on
it before I posted but sometimes I’m trying to get things done quick…

This project was evolving, originally, I only used the extender to put some post for gnd and analog output. So was using that first by itself.

Then later (today), was thinking to put on an SD module, so I went to visual studio to just drag in an sd module and see where it could go. It showed I could either put it on the extender connected to socket 9 or on the socket 5.

So, the software was incorrectly showing it was ok to put the SD module on socket 9 via the extender. Of course this makes no sense but I just got started off on that track and then was building on this faulty idea. When I looked at the 2 sockets I made the wrong assumption that this SD module needed a Y type, so from this, was wondering which pins were used by SD module.

I understand now, all I should have done is see that it uses Ftype then can see in the schematic and should not be fooled by the configuration software.

Also, I think normally, I will never want to steal pins, in this case I was sort of desparately
looking around to see how to scrounge up additional digital i/o’s.

I think now thanks to all you guys help, I can come up with about 26 dig i/o’s which is probably ok for my project.

If not enough, then I will just not use a display which will free up another 14.


#10

I also wanted to note - I didn’t think this was really something you did “wrong”, just more that the “system” allowed you to go deeper than you probably needed to !

Yes, I agree that the “trap” does seem like it has the potential to catch others out, so it’s great we’ve recorded that for posterity. I wonder if this is something the Gadgeteer definition for the Extender needs to be tightened up to prevent this (or if this will always be a challenge). In fact, perhaps a more logical approach now that GHI have the Breakout module and the TB10 module is to remove the extender as an actual module in the designer, since people can achieve the same thing by dragging the TB10 or Breakout onto the design surface (kind of like the micro SD card, just using the SD card module from the toolbox).

Sounds like you’ve got an interesting and evolving project, I love it how the scope always creeps :slight_smile: My own do that too so you’re in company (I won’t say good :slight_smile: ) :wink:

And if you really need more IOs, and you want to keep some kind of display, you can always move to the N18 display, as it uses an S port.