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1  Forum 2005-2010 (read only) / Troubleshooting / Re: Arduino 0007, Windows Millennium slowness on: February 07, 2007, 07:00:56 pm
This is strange. I have successfully used Arduino on an old 400MHz PC running WinXP (now THAT's slow!) without problems.

> judging by all the DOS windows which pop up - 15 to 20 of them

Something's wrong here. That didn't happen on that old, slow computer. Something else seems to be broken.
2  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: serial input from chip on: November 27, 2006, 03:10:38 am
Software serial (serial on pins besides 0 and 1)
3  Forum 2005-2010 (read only) / Interfacing / Re: Arduino and 1-wire on: October 25, 2006, 01:39:02 pm
On this site you can find a nice and fully documented project using 16 1 wire temp sensors with a bunch of Atmegas:


How to connect several 1 wire buses to an Atmega8:

Edit: Google translator is acting up, maybe these links will work?
4  Forum 2005-2010 (read only) / Interfacing / Re: fast serial sendin on: February 09, 2007, 06:03:16 am
Could you try to set the serial speed to a LOWER setting and measure the time again?

According to an article published in Elektor (European electronics magazine):

The often considerably slower data transfer rate of a virtual
RS232 interface connected via USB compared to a
'genuine' RS232 interface deserves some explanation.
Since USB is considerably faster than RS232, it should
be possible to emulate an RS232 interface running at a
speed of say 115,200 bit/s without difficulty: by comparison,
even low-speed USB devices like keyboards and
mice can operate at rates of 1.5 Mbit/s. On the USB
side, the USB-to-RS232 adaptors from [manufacturer1] and
from [manufacturer2] both operate in USB version 1.1 full speed
mode, with a data transfer rate of 12 Mbit/s. One would
think that this would be more than enough to emulate the
fastest RS232 port, but unfortunately there is a snag. Serial
data is transferred over USB in data packets. The data
packets are sent out at one millisecond intervals. The
receiver must check that a complete and correct data
packet has been received and send back acknowledgement
data. The shortest possible turn-around time for
sending a single byte over USB is three milliseconds. As
long as the data packets are sufficiently long, continuous
communication at a speed of 9600 bit/s is feasible over
the virtual RS232 port. This in any case presupposes that
large amounts of data are to be transmitted, for example
for driving a printer or modem. (...) Comparing
the speeds of virtual and real RS232 ports shows that the
USB-to-RS232 adaptor can guarantee to match the speed
of the real port up to about 9600 bit/s. At higher communication
speeds it starts to fall behind, since each byte
must be sent individually on the one millisecond timebase.
The transfer in this case will thus take exactly
60 ms for the 60 bytes.
The behaviour described above was observed under
Windows XP for both the adaptors tested. In comparison,
a genuine RS232 interface running at 115200 bit/s will
transfer 60 bytes in approximately 5 ms; the USB-to-
RS232 adaptor takes twelve times as long!
Things take even longer when relatively small quantities of
data need to be transferred back and forth alternately. For
example, in a microcontroller system a series of command
bytes may need to be transmitted and the microcontroller
may need to reply to each byte received: the USB protocol
will now bring the system grinding practically to a
halt. Irrespective of the direction of transfer, each byte will
take three milliseconds to send and hence the effective
data transfer rate will be just 167 bytes per second.
This example also shows that the data transfer rate will
increase if it is not sent one byte at a time, but rather in
groups of bytes.

From: USB-to-RS232 Hurdle Race
adaptor problems and tuning tips
elektor electronics - 9/2005 - page 38
5  Forum 2005-2010 (read only) / Development / Re: radio frequency broadcasting on: January 10, 2007, 04:53:08 pm
"I'll bet I can get an Atmega8 to serve as a cheap, precise arbitrary square wave generator."

"An extremely simple and low cost Sine/Square wave generator based on the Analog Devices AD9835 Direct Digital Synthesis (DDS) Generator chip. The frequency can be set for any frequency from 1Hz to 10MHz in 1Hz resolution steps."
6  Forum 2005-2010 (read only) / Development / Re: ardiono & speakjet? on: March 11, 2007, 03:31:49 am
7  Forum 2005-2010 (read only) / Development / AVR-USB firmware on: December 29, 2006, 03:25:42 am
A Firmware-Only USB Driver for Atmel AVR Microcontrollers

A USB device without dedicated USB hardware

AVR-USB is a firmware-only implementation of a USB 1.1 compliant low-speed device for Atmel's AVR microcontrollers. It runs on any AVR microcontroller which has at least 2 kB of Flash memory, 128 bytes RAM and can be clocked at 12 MHz. No UART, timer, input capture unit or other special hardware is required (except one edge triggered interrupt).

AVR-USB can be licensed freely under an Open Source compliant license or alternatively under a commercial license.

    * Fully USB 1.1 compliant low-speed device, except handling of communication errors.
    * Supports two endpoints: one control and one interrupt endpoint.
    * Transfer sizes up to 254 bytes.
    * Comes with freely usable USB identifiers (Vendor-ID and Product-ID pair).
    * Customizable sections are written in "C" and are well commented.
    * Delivered with fully functional example applications.
    * Only about 1400 to 1500 bytes code size for basic functionality.
    * You can choose the License: Open Source or commercial
8  Forum 2005-2010 (read only) / Troubleshooting / Re: 168 Bootloader Error on: February 28, 2007, 07:25:15 am
> I'm glad to help any way I can.  

Write it down in a way that every n00b can understand and post it on the playground.
9  Forum 2005-2010 (read only) / Troubleshooting / Re: 168 Bootloader Error on: February 20, 2007, 05:42:43 am
I probably shouldn't be posting here since I obviously have no clue, I guess I'll do it anyway...

You mentioned:

> ATmegaBOOT_168_CRUMB168_F20000000_050815.hex

The Crumb168 is a microcontroller module similar to the Arduino Mini

Are you sure this bootloader will work with the Arduino? Do they both use the same bootloader?

10  Forum 2005-2010 (read only) / Troubleshooting / Re: 168 Bootloader Error on: February 19, 2007, 12:50:57 pm
I am a bit confused due to the sometimes conflicting information.
Which ISP programmer will work and which one won't? Can I get away with using a quick and dirty parallel programmer? What about all those non-Atmel programmers which claim to be STK500 or AVR ISP compatible (but sometimes have additional features, like USB)? Don't want to spend lots of money on an Atmel serial programmer when I can get a compatible one with USB for a fraction of the money. And then it supposedly seems to depend on which OS and programming software you use... Too much input.

So what's the consensus for the most reliable and cheapest idiot-proof programmer out there? Can't hurt if it's available locally so it doesn't need to be ordered abroad which usually adds a lot of taxes and postage.
11  Forum 2005-2010 (read only) / Troubleshooting / Re: is that a Java tutorial? on: February 24, 2007, 08:18:22 am
ArduinoBT and cell phones:
12  Forum 2005-2010 (read only) / Troubleshooting / Re: Arduino NG to DB9 serial on: February 10, 2007, 07:54:06 am
The easiest way is probably getting an internal USB-PCI card for that computer.
13  Forum 2005-2010 (read only) / Troubleshooting / Re: ATmega168 in DIP28 format on: January 10, 2007, 04:45:54 pm
User bigfun is selling Atmega168 with the arduino bootloader. So it is possible. Check this thread:

can I then just write programs using the Arduino IDE and then upload the compiled .hex file without issues?

Yes, you can use Arduino sketches without the bootloader.

"If you have an external programmer you can burn sketches to the Arduino board without using the bootloader. This allows you to use the full program space (flash) of the chip on the Arduino board. It also avoid the bootloader delay when you power or reset your board."

14  Forum 2005-2010 (read only) / Troubleshooting / Re: ATmega168 in DIP28 format on: January 10, 2007, 01:17:11 pm
If you have an Arduino board you can use it as an ISP programmer for other boards or just the ATMega168 processors.
15  Forum 2005-2010 (read only) / Troubleshooting / Re: USB Connector from Farnell? on: January 10, 2007, 01:20:14 pm
The USB socket on the Arduino NG seems to have the same pinout, so it should work.
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