Main Site Documentation

Using SK Pang Arduino CAN-BUS with a EM-406a


#1

Hi everyone,

Has anyone had any success accessing an EM-406a GPS unit from the SK Pang CAN-BUS shield from NETMF on the Domino, or any of the FEZ range?

I know that the GPS unit is on Pin 5 and 6, and I can’t seem to work out how to access a Com Port on pins 5 and 6.

Any help would be greatly appreciated.

Cheers and thanks in advance…


#2

There are 4 serial ports on usbizi. Take a look at your board’s manual to see where they are located. You may have to do some wiring.


#3

Thanks for the info Gus.

By wiring, I am guessing you mean soldering wires?

I have no idea how to solder, and so I really need to try and achieve this through software alone if possible.

As suggested, I have looked at the Domino Brochure, and I note that it is possible to re-map COM4 from D17/D13 to something else. What I don’t understand is the following code:


Register PINSEL9 = new Register(0xE002C024);
PINSEL9.Write(0);// COM4 is now disconnected from P4.28 and P4.29
Register PINSEL1 = new Register(0xE002C004);
PINSEL1.SetBits(0xf << 18);// COM4 is now connected to An3 and An4

How are the numbers 0xE002C024 and 0xE002C004 calculated in order to specifically disconect from P4.28 and P4.29 and then reconnect to An3 and An4?

Sorry, I am very new to embedded programming; I normally deal with VLDBs.

Cheers and thanks in advance…


#4

The mapping is only possible for those pins and only as described in manual. Software UART implementation is horrible in my opinion, uses too much resources for very little benefits.

Why not try to solder some wires? I am sure many here will help with pointers… are you up for a challenge? :slight_smile:


#5

Well; looks like I really should take up the challenge :slight_smile:

Given that the CAN-BUS shield fits directly on top of the domino, I am guessing that I should probably have something between the two shields for the soldering to work.

Any recommendations on what I can use between the two shields - an extention board, or bread-board maybe?

Cheers and thanks for your help Gus,
Nik


#6

Nik, best bet is to use the “bend the pins” method.

If you don’t have stackable headers, then you can simply solder onto the top of the header pins on your shield.

Bend out the pins that stick out the bottom of the shield (a more permanent method is to snip them off).

Solder a jumper wire from the top of the pin you just cut off to the new pin that you want to use. Repeat for the other pin. Make sure you don’t swap RX and TX :slight_smile:

The alternative is, if you’re just using the GPS, to figure out a way to direct connect the GPS pins to your Domino


#7

Hi,

Looked at the schematic. Looks like you can route the GPS to D0/D1 by changing SJ1 and SJ2. They look like Soldered Jumpers…

Thanks,
Errol


#8

Hi Brett and Errol,

Thanks for the suggestions :slight_smile: I really appreciate everyone’s help on this one!

When I bought the unit, I ended up buying the breakout board for the EM-406a also, just in case…

Looking at your suggestions gave me some inspiration; that is, to try using the breakout board first as all I need to do is to add the header to the board and then plug that directly over the top of the CAN-BUS shield. Theoretically, I would just need to plug it in the right spot and all should be fine.

If that doesn’t work, I can still try either of the ‘Bend the pins’ method or re-routing through SJ1 and SJ2 which seem to me to be more advanced (for me) versions of the above, but also probably more likely to succeed than my thought… :slight_smile:

For completeness, I will report back relative success or failure of each of the techniques I have used so that this can become a case study for combining the CAN-BUS with GPS on a Domino.

Once again, thank you Gus, Brett and Errol for all your assistance!

Cheers and thanks
Nik