Can the USB spare connector be used for MEGA Programming?

[Steve S]

Hey Rob,

All boards have been positioned in my case and the R-T tested, so today's the big day to start my cuts... you know, measure two - to three hundred times, cut ONCE...
I had been planning on running a C2G extension cable from the Mega to the outside of the case so I don't have to crack the case every time I want to load an update. As I am marking the template for the connector board, I remembered you have a spare USB female type B at position X12. The traces seem to go to the four pins at JP11 and that's just all, nowhere else. Since I have to cut the case for this connector so the PCB will mount flush to the case, why not use it rather than cutting another hole for the extension?? I thought I asked you this earlier, and got a NO reply, so I'm just checking to see if, maybe I asked the question wrong, or maybe I've just gone batty! If so, could I just run yo-yo jumper wires to a male type B USB connector? if so, that would be a real clean way to update the Mega and you should mention it in the manual (if you haven't already done so and I missed it).

This is a standard for wiring the type B I found online 

                                  

Do you know if this will work???  Do I even need pins 1 and 4 as the Mega gets it's power from the connector PCB?

Thanks

Steve

[Rob F]

Hi Steve, yup measure and measure and cut slow. ;) Sorry I missed your question, with our page long emails its hard to catch everything. On the board you have you can use the USB-B jack for programming, the boards now have that jack hardwired for the expansion hub. It sounds like you have the hub connected directly to the board so you won't need the jack for that. If you use jumpers from the arduino to the connector board it'll work, make sure you don't cross any pins otherwise the mega could be damaged. If you keep pin 1 to pin 1 etc... it'll be ok. I agree you shouldn't need to run power wires as you won't be powering the arduino via the USB.

[Steve S]

Now I remember!
Sorry. I wasn't clear on my communication just now. Rob, you didn't miss the question as in NO reply, your reply was NO!!!  It's been a while back that I asked about the USB-B connector and you told me "NO" it was reserved for the expansion board. I think when you previously answered, you may not have remembered that I had an early version of the connector board and not the current version that uses the USB-B for the expansion board.

Your build designs of the PCBs are oriented towards modular or separate components. I would normally go that route as I feel they can be far more flexible, however I am creating an all-in-one cabinet (to replace my existing plastic shoe box hardwired mess for my previous Arduino). One cabinet houses all the boards AND the power supply for my LED lights. I am making as many internal wiring connections as possible. I find that I am having to make some modifications, like in retrospect, I would have had you install straight headers for internal connections rather than the 90 degree headers for the EXTERNAL pwm outputs. Needle nose pliers and a steady hand took care of that one!

I have not yet purchased the expansion unit as it wasn't even in the planning stages when I bought an early R-T kit. So when I DO add the expansion board, WHERE does it get hardwired to the connector board?  Also, I am using a single DB-25 straight cable to create a harness for connecting to the lights, fans and temp. I will be utilizing the spare wires for power to the fans and a couple of DS18B20 to monitor light and hood temps for fan control. Since the cable connects to a female DB-25 connector in the case, I will want to connect internally to the PCB and bypass the external RJ-14s. I plan on soldering directly to the PCB behind the RJ-14 connectors. 

Will that work? Any thoughts, Rob??

[Rob F]

Ah, sorry I'm all mixed up, I thought you already had the hub. If you want to use the USB-B on the board for programming its ok, if you get the hub its easy to connect directly to the board using jumpers soldered to the board, I'll send you images how to connect them.

You shouldn't have any problems running jumpers for the jacks on board to your DB-25, I would do it as you described. Technically you can do that to all the jacks and use whatever connectors you want, you could place the board in the box and not cut any holes for it, just run wires to from it to your DB style connectors.

[Steve S]

... not cut ANY holes!!!
What a great idea...

After I just spent all day using a Dremel to create and needle files to clean up the holes! 
And HOW MANY more needed for the expansion board??    ;-)

Maybe I'll keep them all internal for my next Robo-Tank ver 2.0 project!

Thanks for the info.
Now back to the FUN part of the build.

[Rob F]

Lol, yeah no holes, I thought you might like that. Another way it could be done easily if you didn't need access to the plug, place the boards in a larger box and drill holes for the cable. Run the cable through the holes and either solder to board or add the connectors and plug them in. Lots to cut for the expansion hub, it has 17 plugs + programming port.