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571  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: ATmega8U2 on: November 15, 2010, 01:27:42 am
this is a good question, the ATmega8U2 could be connected to the SPI bus of the ATmega328P, and just left floating until the right command comes along. This wouldn't interfere with backward compatibility or any devices at all.
572  Forum 2005-2010 (read only) / Interfacing / Re: Decoding Radio Control signal pulses on: March 11, 2009, 10:50:39 am
oh i totally agree that it's overkill, the RC radio would need a 16 bit ADC for the joystick if it wants to make the accuracy worthwhile, i'm not dividing my timer so i'm getting 0.05 microsecond resolution if i run my chip at 20 MHz
573  Forum 2005-2010 (read only) / Interfacing / Re: Decoding Radio Control signal pulses on: March 11, 2009, 10:06:40 am
Hi, I have a suggestion for the code, instead of using "TCNT1 = 0;", why not remember the previous value of ICR1 and keep track of overflows, this way you can get an unlimited value for the pulse width, also it's more accurate since it takes a few clock cycles to clear TCNT1

The only thing that can go wrong is if the capture event happens when TCNT1 is 0 and the capture interrupt executes before the overflow interrupt
574  Forum 2005-2010 (read only) / Interfacing / Re: Load sketch code from SD Card on: December 18, 2009, 12:37:19 pm
I think we are all interested in seeing your work
Are you using any of the popular FAT libraries?
Does it handle verification? How does it handle verification (page by page or all at once at the end)? What does it do when there is a mismatch?
575  Forum 2005-2010 (read only) / Interfacing / Programming by IR with Vishay TFDT4500 on: November 15, 2007, 12:58:53 am
The Vishay TFDT4500 is specially designed for infrared serial communication up to 115200 baud, does anybody have any experience using such a device? Are there going to be any problems regarding reflections?

Found here
576  Forum 2005-2010 (read only) / Interfacing / Software Serial Outputting Null Character on: September 30, 2007, 03:09:39 pm
The baud rate is 9600, I am using the Arduino's debug terminal to read what the Arduino outputs, all I see is a bunch of boxes.
I am reading over the library files, I don't think there is a stop bit, should I add that? Should I fine tune the delay and how?
577  Forum 2005-2010 (read only) / Interfacing / 115200 baud rate on: September 11, 2007, 03:28:44 pm
the atmega168 datasheet says with a 16mhz xtal, there is -3.5% error for 115200 baud rate. I need to interface with a AVRcam, which only uses 115200 baud and uses a atmega8 with a 17.7mhz clock. Will it work?
578  Forum 2005-2010 (read only) / Exhibition / Image Data From ADNS2610 Optical Mouse Sensor Via on: November 27, 2010, 04:51:16 pm
Demo Video:

I check SparkFun's new products pretty often and spotted the ADNS2610 optical mouse sensor. The datasheet shows that it's easy to use, just read the delta-X and delta-Y movements, and it can also provide a 18x18 pixel greyscale image.

It involves using V-USB on the USnooBie to provide the AVR microcontroller with USB capability, some example code from SparkFun to read data from the ADNS2610 sensor, and a C# Windows application using LibUsbDotNet to read data from USnooBie to display the picture provided by the optical sensor.

Project file downloads, relevant links and resources are found here:
579  Forum 2005-2010 (read only) / Exhibition / Re: USnooBie Kit - AVR USB Device Dev Kit on: November 26, 2010, 08:40:00 pm
I like your initiative to abstract USB keyboard functionality (and others) into a C++ library/class. It's also great to read some of your Python examples (even though I don't know it).

I just tried to write a core with V-USB, and it seemed like there would be no good way to make each project independently configurable. This is mainly because of Arduino's build steps, which do not allow any part of the core to depend on a part of a sketch.

V-USB and Arduino's IDE just don't mix well.
580  Forum 2005-2010 (read only) / Exhibition / Re: USnooBie Kit - AVR USB Device Dev Kit on: November 16, 2010, 02:41:54 pm
Frank I did not mean to detract from your achievement.

I didn't take it as such, I was just explaining.

USB is not complicated once you take some time to understand. What I think USB is great for is when you need to give meaning to your data. HID reports are organized into "usages" and requests have a header that contains parameters such as "request type", "index", and "value". This makes code easier to write, maintain, and understand. is a great resource

It is also possible to program the USnooBie itself to become a serial port device but according to what I've read, this may not work on all platforms and will take up a lot of CPU time on the ATmega.
581  Forum 2005-2010 (read only) / Exhibition / Re: USnooBie Kit - AVR USB Device Dev Kit on: November 15, 2010, 12:17:15 pm
It was never originally designed for Arduino users. I hoped to create something that lets people experiment with real USB devices before taking their design from a development platform to a standalone device.

I don't even think it's practical to compile V-USB with Arduino. I'm hoping some brave Arduino users will get bored with just reporting data back from the serial port and switch to a good development environment instead and try out V-USB. I have a few videos showing you how to work with V-USB and also writing computer side drivers.

If you really need the serial port, just buy the FTDI cable and connect it to the TX and RX of the ATmega, just like how most Arduino derivatives requires you to anyways.
582  Forum 2005-2010 (read only) / Exhibition / Re: USnooBie Kit - AVR USB Device Dev Kit on: November 14, 2010, 01:29:08 pm
Carl, I think I worded my last post wrong, what I meant was

The timer overflow interrupts used by the Arduino core to keep track of millis may cause higher interrupt latency for the INT0 external interrupt. Also there are Arduino core functions which disable interrupts globally such as the microsecond delay functions.

V-USB requires low interrupt latency and also for the interrupts to be enabled all the time. Hence I think I need to modify the Arduino core so that it is friendly with V-USB


trialex, you can't use the serial monitor without connecting a serial port or a serial port to USB converter.

I hope all Arduino users understand that the serial port functionality usually comes from a built-in FT232 chip, a FT232 cable or similar, or the ATmega8U2 (on the Uno board) which does the exact same thing as a FT232.

I did not include this FT232 because it would add to the cost and size significantly, and many Arduino derivatives do not include this chip or cable.

You are free to purchase an FT232 cable separately in order to use the serial port monitor, but unlike Arduino, it is not a requirement for USnooBie to be programmed.
583  Forum 2005-2010 (read only) / Exhibition / Re: USnooBie Kit - AVR USB Device Dev Kit on: November 13, 2010, 12:36:23 am
If you use the Arduino IDE then you can't use V-USB though, I'm going to see about writing a core that works with V-USB. The problems will arise from whether or not Arduino is smart enough to compile .S files, the timer interrupts, and also functions which disable interrupts.
584  Forum 2005-2010 (read only) / Exhibition / Re: USnooBie Kit - AVR USB Device Dev Kit on: November 12, 2010, 09:20:47 pm
I just wrote a page detailing how this can be used with the Arduino
585  Forum 2005-2010 (read only) / Exhibition / Re: USnooBie Kit - AVR USB Device Dev Kit on: October 27, 2010, 11:53:42 pm
The 2nd push button is used to activate the bootloader, please see the usage guide to learn how it works

There is no good way to make a auto-reset function because I am not using a USB-RS232 converter. A timed bootloader is also annoying. The button occupies one of the USB data lines being reserved so it causes minimal loss of available pins.
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