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I bought a cheap "Make" kit at RadioShack, which includes some sort of proprietary Arduino Uno compatible motor/sensor shield. Naturally, the documentation is pretty bad. The documentation and Arduino code for the kit is here:

https://github.com/RadioShackCorp/2770168-MakeItRobotics-Starter-Kit

It includes a circuit schematic (2770168-CorePCB_schematic.pdf), but I'm still having trouble mapping the pins to the Arduino's pins. Can anyone help me make sense of this?

What I've made out so far is the shield's screw terminals appear to be connected to quadruple h-bridges. However, there are several other pin headers that I can't quite make out. I think it also directly exposes 4 of the Uno's ADC pins and 4 DIO pins. There are four pins for dual IR line sensors, but there's a lot of circuitry between these and any Arduino pins. Almost everything feeds into a DC6688F2SCN chip, but I can't find a datasheet anywhere, so I have no idea what it does.

The manual says jumpers on J16 need to be removed in order to connect to the Uno over USB, so it looks like I can't use the shield with the board and debug via USB at the same time. Is this board worth investigating or should I trash it?

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  • dragonchip.com/TechDoc/DC6688.htm
    – Ignacio Vazquez-Abrams
    Oct 21, 2014 at 1:06
  • @IgnacioVazquez-Abrams, Yeah, I found that too. It contains no documentation...unless you count a Windows exe as "documentation". When did people stop publishing datasheets as PDFs? Either way, that doesn't help me on my Linux box...
    – Cerin
    Oct 21, 2014 at 6:10
  • That seems to be a PDF in an encrypted SFX zip, but I haven't actually tried running it yet.
    – Ignacio Vazquez-Abrams
    Oct 21, 2014 at 6:24
  • The DC6688F2SCN is clearly a microcontroller, so what matters is not really its data sheet, but rather its custom firmware. The schematic appears to show it connected to Arduino Digital Pins 3 and 4, so you'd need a software serial on those to exchange commands with it, once you figure out its baudrate and language. In the version of the schematic provided, there doesn't seem to be any cross connection to digital pins 1 and 2, but if there were that would interfere with the USB-serial (while allowing use of the ATMega's hardware serial to talk to the DC6688F2SCN).
    – Chris Stratton
    Oct 21, 2014 at 18:44
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    I'm voting to close this question as off-topic because link rot. The schematic linked by the OP doesn't longer exists and the question is now unsolvable.
    – user31481
    Nov 24, 2017 at 9:12

2 Answers 2

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There is a bit of info on the DC6688F2SCN here: Chip Selection Guide, but Chris is 100%. Without the firmware, all you can do is look at the source code for the Arduino side.

If you look closely at the top of the board, you can see that one side of J16 goes to pins 2 & 3 and the other to 0 & 1. On the schematic, there are some other components hooked in there as well. The serial is definitely going using 0 & 1. I'm not sure why they have them wired to 2 & 3. It's probably a good idea not to put anything on any of these four pins.

That's pretty good though. Compare it to the SainSmart L293D shield, which is significantly cheaper but eats up eight digital pins when driving four motors. Also, the L293Ds can only put out 600 mA per channel while the Bs can do a full Amp.

The documentation isn't very good and the supporting code also has some issues; but, overall, this is a pretty decent package. It comes with the erector set pieces as well. You also get three IR sensor channels.

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A google search for DC6688F2SC returns spec sheet under Dragonchip (here). It's actually a rather nice chip when you look up the specs on it.

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    Unfortunately, this does not add much over the comments already made. Please see Ignacio's comment from last year. If you could expand your answer, then that would be great.
    – Greenonline
    Sep 25, 2015 at 9:16
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    @Greenonline please see meta.stackexchange.com/questions/117251/…. "Answer stealing" from a comment is considered okay on Stack Exchange
    – Anonymous Penguin
    Sep 25, 2015 at 21:41
  • @AnnonomusPenguin - Granted, but I was just trying to encourage thomas to expanded the answer somewhat, if at all possible. :-)
    – Greenonline
    Sep 25, 2015 at 21:59
  • @Greenonline yes, the OP should expand the content of their post.
    – Anonymous Penguin
    Sep 27, 2015 at 17:51

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