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1  Using Arduino / Networking, Protocols, and Devices / Re: Itead BlueTooth Master on Uno plus Samsung Galaxy 2 Tablet on: February 27, 2013, 05:59:52 am
FYI, this morning I was able to get the tablet paired with the BT shield, by placing the BT shield back into SLAVE mode, using the 'AT+ORGL' command.

I have not tried any communication between the two yet.
2  Using Arduino / Networking, Protocols, and Devices / Itead BlueTooth Master on Uno plus Samsung Galaxy 2 Tablet on: February 26, 2013, 07:02:40 pm
I read over this post, but it was not exactly about my issue:,97971.0.html

I would like to know if anyone is using the ITEAD BT Shield V2.2 in Master mode. I'm trying to pair that device with my tablet.

With the BT shield on the Uno, and the jumpers set properly, I can talk to the BT shield via 'AT' commands at 38400 baud. Using the 'AT+INQ' command, it does show my tablet's BT address, but I cannot get the two to pair via 'AT+PAIR' or 'AT+LINK'. If I use 'AT+STATE?', it shows 'INQUIRING', but never gets beyond that state.

Anyone trying to use the BT shield in Master mode? I would appreciate any help. Thanks!!
3  Using Arduino / Project Guidance / Re: Your Wish List on: January 29, 2013, 07:59:27 am
Sorry for the slow reply; I haven't checked the email for this account in a while. I think I'm going to switch which email is used.

Anyhow, have you solved your problem yet? If not, what are you really trying to accomplish? Why won't the 7-band EQ work for you? Have you looked at other EQ chips that may have more bands?

What do you mean by "hundreds"? Do you have a budget of price/unit? In other words, how worthwhile is it for someone to attempt to create this device for you?

4  Using Arduino / Microcontrollers / Re: Blinking LED 13 on: September 12, 2012, 08:45:12 pm
One thing that I've run across in several circumstances, that has not been mentioned here, is HEAT. Sometimes a board can appear to work fine for a while, then suddenly stop working or behave strangely, because the chips reach a certain temperature. Since that temperature may vary from location to location, it might work for you when it does not work for the client. Swapping boards can help, but it does not necessarily rule out this scenario, because the two boards may have been produced with specific parts (e.g., resistors or capacitors) from different manufacturers, with different tolerances or heat ranges. I don't know if this is your issue, but I just wanted you to consider the possibility.
5  Using Arduino / LEDs and Multiplexing / Re: 3x3 LED mulitplexing question on: September 09, 2012, 09:56:49 am
I don't know how familiar you are with using macros in C/C++, but they can make the task of storing constant bits in packed bytes a lot easier. Also, if you use the "const" keyword for arrays which should be constant, they should be stored in Flash area, not in SRAM, saving the precious SRAM space. Here is a small example of defining a graphic character using macros. This 8x8 pixel character (including space) uses only 8 bytes of constant Flash memory. Please note that I coded this on-the-fly and have not compiled it, so...

#define ROW(b7,b6,b5,b4,b3,b2,b1,b0) \
static const byte Graphic[] =
6  Using Arduino / Project Guidance / Re: 4 pushbutton lock coding on: September 09, 2012, 07:35:06 am
One thing I forgot to mention... the blue lines represent moving to the next state when the proper button is pressed. The red lines represent moving to the next state when the wrong button is pressed (blue-to-red state transition) or when ANY button is pressed (red-to-red state transition).
7  Using Arduino / Project Guidance / Re: 4 pushbutton lock coding on: September 09, 2012, 07:32:17 am
I agree that clarifying the state machine will help to solve this problem pretty quickly, so I have attached a sample state diagram. You must be logged in to see the attached GIF image. The boxes are states. The lines are transitions between states, caused by button press events. One thing that came to my mind while reading this forum thread is that you were not accounting for the fact that you do not want to show the person whether the entire set of 4 button presses is correct or incorrect until after all 4 buttons have been pressed. This is a standard way of preventing the person from learning the passcode just by pressing random buttons. So, you should not light any LEDs until all 4 buttons are pressed, represented by the "Correct" and "Incorrect" states in the diagram.

If you implement this diagram using a single variable to hold the state identifier, and always check for a button press in the loop, based on the current state, then there is no need to wait for anything. The delays are inherent. The only time a delay is needed is when lighting the LED for an amount of time, and of course, you can use the state variable and a clock time variable to know when to turn off the LED, so your code does not need any delay statements at all.

Hope that helps.  smiley
8  Using Arduino / Project Guidance / Re: Your Wish List (TANKS) on: September 09, 2012, 07:08:30 am
I did just a couple of minutes of research on the chemical sensor thing, and quickly discovered that the idea of designing new sensors is probably outside my scope, not being a chemist. Given an existing sensor and its datasheet, I could probably figure out how to control it, but creating a new sensor from scratch is not something that I have the time or resources to do. So I think someone else will need to investigate that idea.

Has anyone done any research to see if less expensive sensors exist?
9  Using Arduino / Project Guidance / Re: Your Wish List (CAM) on: September 09, 2012, 07:05:34 am
Attached are the latest copies of the source files for accessing the SRAM for the camera. I did a basic desk run (i.e., on paper) and found a few issues. I can't really do full debugging, since I have no hardware at this point. But I think this library code is a pretty good basis from which to build an application, assuming you have hardware to play with.
10  Using Arduino / Project Guidance / Re: Your Wish List on: September 07, 2012, 07:22:59 am
 smiley-cool Here is the VERY first cut of the source code to access the SRAM. Please note: I have no hardware. This code will compile, but has not been tested AT ALL. I have not even done a "desk run" yet, so it PROBABLY has bugs in it!! I'm attaching it here, just so you can peruse the code and notice and glaring errors. Thanks.
11  Using Arduino / Project Guidance / Re: Your Wish List on: September 06, 2012, 03:49:09 pm
Hey, sbright33: smiley-roll-sweat Whew! Good to know. I was starting to wonder if I was shooting in the dark. I had a strong feeling that you were just tied up. In any case, I just keep going, anticipating your reappearance. I sent you a Skype request, too, so if you want to chat about progress or questions, we can do so offline. I would like to do that, to talk about next steps, relative to a prototype.
12  Using Arduino / Project Guidance / Re: Your Wish List on: September 04, 2012, 05:20:12 am
Oops. While doing some coding, I realized that I made a couple of mistakes in my circuit drawing. First, the 8 data pins going to the SRAM chips must be tied together between the two CPUs; otherwise, each CPU cannot reach both banks of SRAM chips. I added the lighter green lines to make those connections.

Second, the SCK pins must all be tied together. This enables toggling a single output pin (PD3) to manipulate the SCK pin on all SRAM chips. Keep in mind that only 2 chips are enabled (NCS) at any given time. I tied together the light gray and light orange lines, and removed the use of PD2 (it is now free).

Additionally, I threw in some black connection indicators, to make things easier to see.

The resulting changes are in that attached GIF. Care to review? Thanks.  smiley-confuse
13  Using Arduino / Project Guidance / Re: Your Wish List on: September 02, 2012, 06:16:31 am
fyi, I'm working on an Arduino-style library (i.e., C++ code) to be used to access the SRAM on the CamRAM512 (rev 2) setup.  smiley-cool
14  Using Arduino / Project Guidance / Re: Your Wish List on: September 01, 2012, 07:14:38 pm
So here is revision 2 of the design for adding SRAM to the Uno(s). This picture supports sharing the SRAM between 2 Unos, and using a SPI (actually SQI) operation (without the SPI peripheral) to store/load 8 bits at a time (4 bits in each of 2 chips). There are 2 banks of 256KB each, totalling 512KB. I think it could work, but would require some careful programming on both CPUs (not a big deal, just have to get it right). See attached image. Again, login first!

And no ARM CPU involved. Long live the AVR!  smiley-roll
15  Using Arduino / Project Guidance / Re: Your Wish List on: August 31, 2012, 05:50:59 pm
I should have checked my GIF before responding. Turns out that the I2C pins are free (SDA & SCL), so we could use those for data between the 2 CPUs; however, it would still be better (faster) if we could omit that extra serial hop for every data bit!
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