At present time is USB interface very popular especially within end user.
This is due to the simplicity to the end users (Plug and Play, without
restart). For developers is implementation of USB into their devices
more complicated (with comparison to RS232 is USB more complex protocol).
In addition there is need of software support on PC side - device drivers.
Therefore more devices from small vendors are inclined to RS232 communication.
This interface is probably the oldest in PC history and has good operating
system support. But in latter years is RS232 removing from standard included
PC interfaces (new computers hasn't RS232). In this case help only add-on
PCI card with this interface.
Implementation of USB into external devices is at
present time solved in two choices:
- First is using microcontroller, which have hardware
implemented USB interface. Then is necessary to know how USB
works and according this write firmware into microcontroller. And in
addition is necessary to create driver on the computer side (while operating
system not includes it - e.g. standard USB classes). Disadvantage (and
this is the main disadvantage for small vendors and amateurs) is not
good availability of this microcontrollers (PIC, Cypress, Atmel, Intel,...
) and their high price (with comparison to simple "RS232"
- Second option is to use some universal converter
between USB and "another" interface. This "another"
interface depends on type of convertor: there are used especially RS232,
8-bit data bus, I2C bus. In this case is not need of special firmware
(actually we needn't to know how USB works) and no need of driver writing
(vendor of converter offer free drivers). Disadvantage is higher price
of the complete device and greater dimensions of product (need of one
This device allow:
- It works with the USB-interface for controlling the PC with a standard
- It can work with Girder
- It is connected to the USB-port with a standard USB A cable (1~1.2m).
- No requires additional power supply.
- Receiving of infrared code (time diagram of received code) (it is
transmitted to serial line in real time too)
- Receiving of infrared code makes by AT90S2313-10 microprocessor without
PC cpu time usage - zero usage of PC CPU ( for the IgorPlug-Serial,
it use about 10-15% PC cpu time usage. )
- Control of 8-bit input-output data gate (every bit can be independently
input or output, there can be independently controlled pull-up resistors
on input pins)
- Reading and writing of internal 128 byte EEPROM (storing of data after
no power state - for users is accessible all memory)
- Transmitting or receiving char via serial line
(now only one non buffered char - but by firmware change is possible
to make internal buffer (for injury of infra buffer) : like FTDI chips)
- Change of baudrate of serial line in range cca 4800Baud to 700 000Baud
(after power on is 57600baud)
("Classical" baudrates are: 4800, 9600,19200,38400,57600.
Device DLL automatically detects invalid baudrates.)
- A small USB driver must be installed (available for download).
- Free or shareware programs under Windows 95, 98, NT4, 2000, XP operating
systems can be controlled with an I.R. remote control.
- Setting and reading of 8-bit data port (see schematic).
- Port bits flow control and back reading of state of this flow control.
- Control of pull-up resistors on data pins (pull-up enabled, or high
impedance input) and back reading of this state
- Reading data pins level state (refresh every 200ms).
- Setting LED diodes, which are connected to data pins through resistors
(cathode on GND, is necessary to set all bits as outputs).
- Reading data from all EEPROM.
- Writing data to all EEPROM.
- Writing - transmitting data to microprocessor serial line.
- Rreceiving char(s) from serial line (polling every 100ms).
- Changing serial line baudrate (invalid baudrate - baudrate with error
greater than 4% - is displayed as crossed number, unsuccessful set is
signaled by red color in baudrate box).
- Back reading of internal true baudrate (polling every 100ms).
- Receiving of oscilloscopic record of infrared code received into internal
microprocessor buffer (refresh every 50ms)
(received infrared code is displayed in graphical form as on oscilloscope
- its decoding must make another application)
(during infrared code receiving is this code transmitted to serial line
too - but "on the fly" - therefore is necessary to set high
baudrate of RS232 - therefore after power on is baudrate 57600 Baud).
|If you don't wish to construct IgorPlug-USB(AVR)
by yourself, we can offer you the ready made device.
The offer price for this device is US$38.00
per unit. ( This price include postage, license driver and license
fee for author Ing. Igor Cesko )
We will post the device to you by registered airmail once the order is
confirmed. It takes about 4 to16 working days ( worldwide airmail )
to reach you depending on the country you reside.
We accept payment via PayPal, Credit Card. and Moneybookers (if you can't pay via
please contact me by e-mail)
For order confirmation please click the below button.
US$38.00 BUY NOW Free Shipping (worldwide).