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46  Using Arduino / Sensors / Re: Issues with recently purchased LM35D on: May 19, 2014, 07:58:27 pm
You should be posting code and circuit diagrams to help us. Circuit is especially import in this case, especially if you have long wires to the sensor.

The sensor is very sensitive to the voltage calibration. I have a library that uses the internal voltage reference to calibrate the sensor voltage. See the link to the repository below, in the signature block.
47  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 17, 2014, 04:17:08 pm
Font can easily be rotated. Use Font builder for that.

The shift functions can be changed. There is a table in the source code that maps the request for a shift to an actual shift. Hardware remapping selects a different shift depending on the configuration. Have a go at that if your feel like it. At the moment I don't have time to go back to these libraries to make major changes.
48  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 16, 2014, 11:27:17 pm
DIn on the right side is good because the module on the right is module 0.

I am not clear what hardware you have selected in the scrolling video. Is it the generic module?

In the hardware test video, your columns are scanning from left to right (ie, col 0 is on the left), so that needs to be reversed with REV_COLS=1. Your rows are scanning from top to bottom, so the rows do not need to be reversed (REV_ROWS=0). I really can't see why that would not work...

49  Using Arduino / General Electronics / Re: decreasing keypad pins on: May 16, 2014, 11:04:11 pm
Lots of keys (100 or more) using 3 pins http://forum.arduino.cc/index.php?topic=235438.0

This is the probably same or similar as the 4017 mentioned above.
50  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 16, 2014, 03:18:16 pm
If understand you correctly the mapping you see , as-is
Code:
 D0 D1 D2 D3 D4 D5 D6 D7
G
F
E
D
C
B
A
DP


This is probably configured as HW_DIG_ROWS=0, HW_REV_COLS=1, HW_REV_ROWS=0. This looks like generic hardware config.

The modules upside down
Code:
 D7 D6 D5 D4 D3 D2 D1 D0
DP
A
B
C
D
E
F
G
This I think is HW_DIG_ROWS=0, HW_REV_COLS=0, HW_REV_ROWS=0.

Neither combination has been tested and probably won't work without some debugging.

Note: Late edit due to error in the explanation.
51  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 15, 2014, 06:32:39 am
Sure, and which LEDs are on when it says that? The point of the test program it to turn on the led and tell you which row/column you are looking at.
52  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 14, 2014, 09:43:10 pm
It is a test program in the MD_72xx examples.

There is a library that you do not have in the Parola test example. That is documented in the code file. You need to read these and not just load and compile.
53  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 14, 2014, 09:37:19 pm
What does the matrix testing demo show?
54  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 14, 2014, 09:01:59 pm
The USE_*_HW defines ultimately are controlling how the libraries behave on a L-R and Top-Bottom. The translation is done in the _lib.h header file. There is a hardware test example that allows you to see which way the matrix is wired so that you can set up the appropriate mapping in the software header file.
55  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 14, 2014, 03:29:04 pm
There are only 2 latest versions in the download sections. So installing those versions should be correct.

The libraries have changed in the latest versions. You need to read the documentation that comes with the libraries as this will be more up to date than the forum discussions.
56  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 13, 2014, 11:04:26 pm
Make sure that you are using a consistent set of libraries with the examples code. Download all the latest and then try again.
57  Using Arduino / Programming Questions / Re: NFC and keypad on: May 07, 2014, 10:21:01 pm
Posting your code and circuit would be a good start to getting help.
58  Using Arduino / General Electronics / Re: led matrix and arduino on: May 07, 2014, 04:59:56 pm
This thread is probably discussing the same type of hardware
http://forum.arduino.cc/index.php?topic=222334.0
59  Using Arduino / General Electronics / Re: led matrix and arduino on: May 06, 2014, 05:03:28 pm
That IC number seems to be the communications buffer. Are there other IC numbers on the display? It is likely that these will be 595 ICs.

The display also seems similar to this one http://www.dzsc.com/product/infomation/832165/2011102885513468.html. Most of the references that come up for the display are Chinese
60  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: May 05, 2014, 04:55:09 pm
Quote
It will be nice if some of us (Arduino rookies) can get the details of how to combine other hardware like the RTC and sensors with the LED modules we've built.

This is an interesting question and I think goes more to the way of thinking about hardware in the Arduino world than the hardware itself. Most of the simple modules used on these forums can be purchased cheaply and provide a few pins to interface to the Arduino hardware. By and large the interfaces are either Direct I/O or consist of ICs with bit-bashing serial interfaces (like the 595 or the MAX7219) or I2C or etc. The key here is that most newbies don't look at the datasheet for the hardware and jump right in, without too much understanding of what they are doing. Reading the datasheet (as difficult as some of them are!) at least gives a reason for why things are done as they are, and builds a knowledge of how to deal with classes of problems. An SPI interface to an IC is pretty much the same no matter what IC it is, so you just need to learn it once.

To take the example of the time and temperature displayed in the example video and sketch. The way I start these things is to build a knowledge of how the devices work (LED display, DS1307 Clock module, Temp sensor) individually. This requires some experimentation and code, independently of the final project device. This can be built up as part of general learning and experimentation (my preferred mode) or just specifically what is required for the project at hand. Google is a big friend here. In the software world this would be consistent with writing a function and a test harness to exercise the code to see 'what happens if ...'.

I use a 'sensor shield' arrangement and build small circuits for individual sensors on a 1"x1" prototype PCB. The sensor shield has standard Ground-Voltage-Signal (GVS) pins for each Arduino I/O and ready made 3-pin connectors can be bought in this configuration. This allows me to quickly combine the devices in different ways to test ideas. Many of the experimenter kits work in a similar fashion, but having to build the small test circuit forces me to read and understand the datasheet. I have described this arrangement much earlier in this thread, I think. [ Edit: Here it is http://forum.arduino.cc/index.php?topic=171056.30].

Once over this hurdle, integrating the devices comes down to what the project is about, which becomes quite specific to the application. The sensor shield once again allows me to mock up a large part of the functionality required before I build the final circuit. I will also, at this stage, usually breadboard some of the circuit that is not standard or too large to fit on the small protoboards.

Hope this helps. My background is in software but by breaking down the hardware into manageable 'subroutines' the ideas behind what is going on become quite manageable and easier to understand and integrate.
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