To be added soon :-
Hardware & embedded...
Driving DC motor using AVR & 8051
Stepper motor interfacing using AVR & 8051
Interfacing ADC , DAC (8051)
Use of inbuilt ADC of AVR
Serial communication using 8051
Serial communication using AVR
Using AVR as DTMF receiver
Interfacing external DTMF reciever with 8051
Parallel processing using AVR / 8051
Triple modular redundancy using AVR / 8051
VLSI
wanna know the effect of shrinking length of MOS transistors...effects on ...Ballistic mosfet ...
MATLAB :: language of Technical computing..
implementation of various theorems & mathematical formulae for the beginners
sound processing & similar applications
image processing & similar applications
interfacing to external hardware using MATLAB
serial communication between 2 PC using MATLAB
MATLAB GUI implementation of various kinds...
LINUX (on http://learncomputersecrets.blogspot.com )
GUI desktop application implementation in linux
IEEE Std 1003.1-1990 POSIX -( portable operating system interface for unix ) -- implementation in linux GCC compiler...for serial communication using LINUX (detailed description)
GRUB details & bootloader options
Playing with GRUB
Visual C++ (on http://learncomputersecrets.blogspot.com)
Parallel port programming
( Without using any DEVICE Drivers access Parallel port in windows XP)
Serial port programming
Image capture from any external WDM device installed on PC
How to start image capture on getting any interrupt
from external device through serial port or parallel port (ie. integrating 1 & 2 & 3 )
Visual C++ object model...for implementation of various constructs used to make multiple dialog application ( using different methods)
Database connectivity by various methods..to different servers..
JAVE Netbeans (on http://learncomputersecrets.blogspot.com)
How to create multiple dialog application with minimum efforts...
How to connect to database to retrieve & store data ( using MS ACCESS , SQL server , ORACLE ,other database softwares)
General knowledge concepts for embedded & computer beginners..
How to learn any computer language in some days with best implementation constructs.
Thursday, May 8, 2008
Whats next......(to be added soon)
USB POWER for circuits.....
Using old conventional methods to get the power for
5V circuits requiring pc interface
or
even if PC is available...
USE USB connector with wire to get 5V supply (regulated) for the circuits....
LDO (low dropout regulator) might be required...but it will give the minimum losses in terms of power..(least dropout)
USB connectors
Jack connector
Pinout description (for both mini usb & usb)
USB
| Pin one side | Signal | Description | Pin other side |
| 1 | USB Vcc (Vbus) | usually RED, wire should be 20-28 AWG | 1 |
| 2 | USB Data - | usually WHITE, wire should be 28 AWG | 2 |
| 3 | USB Data + | usually GREEN, wire should be 28 AWG | 3 |
| 4 | GND | usually BLACK, wire should be 20-28 AWG | 4 |
USB D+ and D- are twisted in cable. Outer shell is made of copper braid and aluminium shield.
MINI USB| Pin | Name | Cable color | Description |
|---|---|---|---|
| 1 | VCC | Red | +5 VDC |
| 2 | D- | White | Data - |
| 3 | D+ | Green | Data + |
| X | ID | May be N/C, GND or used as an attached device presence indicator (shorted to GND with resistor) | |
| 4 | GND | Black | Ground |
USB DETAILS
USB
The Universal Serial Bus is host controlled and there can be only one host per bus. An USB system consist of a host controller and multiple devices connected in a tree-like fashion using special hub devices. Hubs may be cascaded, up to 5 levels. Up to 127 devices may be connected to a single host controller. USB interface aimed to remove the need for adding expansion cards into the computer's PCI or PCI-E bus, and improve plug-and-play capabilities by allowing devices to be hot swapped or added to the system without rebooting the computer. When the new device first plugs in, the host enumerates it and loads the device driver necessary to run it. The loading of the appropriate driver is done using a PID/VID (Product ID/Vendor ID) combination supplied by attached hardware. The USB host controllers has their own specifications: UHCI (Universal Host Controller Interface) and OHCI (Open Host Controller Interface) are used with USB 1.1, EHCI (Enhanced Host Controller Interface) is used with USB 2.0
| Pin | Name | Cable color | Description |
|---|---|---|---|
| 1 | VCC | Red | +5 VDC |
| 2 | D- | White | Data - |
| 3 | D+ | Green | Data + |
| 4 | GND | Black | Ground |
USB pinout signals
USB is a serial bus. It uses 4 shielded wires: two for power (+5v & GND) and two for differential data signals (labelled as D+ and D- in pinout). NRZI (Non Return to Zero Invert) encoding scheme used to send data with a sync field to synchronise the host and receiver clocks. In USB data cable Data+ and Data- signals are transmitted on a twisted pair. No termination needed. Half-duplex differential signaling helps to combat the effects of electromagnetic noise on longer lines. Contrary to popular belief, D+ and D- operate together; they are not separate simplex connections.
USB transfer modes
Univeral serial bus supports Control, Interrupt, Bulk and Isochronous transfer modes.
USB transfer rates: Low Speed, Full Speed, Hi-speed.
USB supports three data rates: Low Speed (1.5 Mbit per second) that is mostly used for Human Input Devices (HID) such as keyboards, mice, joysticks and often the buttons on higher speed devices such as printers or scanners; Full Speed (12 Mbit per second) which is widely supported by USB hubs, assumes that devices divide the USB bandwidth between them in a first-come first-serve basis - it"s easy to run out of bandwidth with several devices; Hi-Speed (480 Mbit per second) was added in USB 2.0 specification. Not all USB 2.0 devices are Hi-Speed. A USB device must indicate its speed by pulling either the D+ or D- line high to 3.3 volts. These pull up resistors at the device end will also be used by the host or hub to detect the presence of a device connected to its port. Without a pull up resistor, USB assumes there is nothing connected to the bus.
In order to help user to identify maximum speed of device, USB device often specify it's speed on it's cover with one of USB special marketing logos.
USB Hi-speed devices
Hi-Speed devices should fall back to the slower data rate of Full Speed when plugged into a Full Speed hub. Hi-Speed hubs have a special function called the Transaction Translator that segregates Full Speed and Low Speed bus traffic from Hi-Speed traffic.
USB powered devices
The USB connector provides a single 5 volt wire from which connected USB devices may power themselves. A given segment of the bus is specified to deliver up to 500 mA. This is often enough to power several devices, although this budget must be shared among all devices downstream of an unpowered hub. A bus-powered device may use as much of that power as allowed by the port it is plugged into. Bus-powered hubs can continue to distribute the bus provided power to connected devices but the USB specification only allows for a single level of bus-powered devices from a bus-powered hub. This disallows connection of a bus-powered hub to another bus-powered hub. Many hubs include external power supplies which will power devices connected through them without taking power from the bus. Devices that need more than 500 mA or higher than 5 volts must provide their own power. When USB devices (including hubs) are first connected they are interrogated by the host controller, which enquires of each their maximum power requirements. However, seems that any load connected to USB port may be treated by operating system as device. The host operating system typically keeps track of the power requirements of the USB network and may warn the computer's operator when a given segment requires more power than is available and may shut down devices in order to keep power consumption within the available resource.
USB power usage:
Bus-powered hubs: Draw Max 100 mA at power up and 500 mA normally.
Self-powered hubs: Draw Max 100 mA, must supply 500 mA to each port.
Low power, bus-powered functions: Draw Max 100 mA.
High power, bus-powered functions: Self-powered hubs: Draw Max 100 mA, must supply 500 mA to each port.
Self-powered functions: Draw Max 100 mA.
Suspended device: Max 0.5 mA
USB voltage:
Supplied voltage by a host or a powered hub ports is between 4.75 V and 5.25 V. Maximum voltage drop for bus-powered hubs is 0.35 V from it's host or hub to the hubs output port. All hubs and functions must be able to send configuration data at 4.4 V, but only low-power functions need to be working at this voltage. Normal operational voltage for functions is minimum 4.75 V.
USB cable shielding:
Shield should only be connected to Ground at the host. No device should connect Shield to Ground.
USB cable wires:
Shielded:
Data: 28 AWG twisted
Power: 28 AWG - 20 AWG non-twisted
Non-shielded:
Data: 28 AWG non-twisted
Power: 28 AWG - 20 AWG non-twisted
MINI USB
USB pinout signals
USB is a serial bus. It uses 4 shielded wires: two for power (+5v & GND) and two for differential data signals (labelled as D+ and D- in pinout). NRZI (Non Return to Zero Invert) encoding scheme used to send data with a sync field to synchronise the host and receiver clocks. In USB data cable Data+ and Data- signals are transmitted on a twisted pair. No termination needed. Half-duplex differential signaling helps to combat the effects of electromagnetic noise on longer lines. Contrary to popular belief, D+ and D- operate together; they are not separate simplex connections.
USB cable wires:
Shielded:
Data: 28AWG twisted
Power: 28AWG - 20AWG non-twisted
Non-shielded:
Data: 28AWG non-twisted
Power: 28AWG - 20AWG non-twisted
8051 Starter for embedded systems....
having problem Using 89C51 ...
low memory (ROM)...4k only 128byte RAM
Difficulty in burning the IC ...
More complex programmers....
So here is a solution.....
Start using 89S series...
eg. 89S52 (8kb ROM 256 byte of RAM space) will be sufficient for most of you...
all ISP using 4 wire interface as is available with AVR
that is... only 4 wires ... RESET,,,,MOSI,,,MISO,,,,& SCK
also it is available at more or less at the same cost...
(ATMEL knows what all wants..)
CIRCUIT 1:
- Designed for new ISP chips, 89S51, 89S52, and 89S53, 40-pin DIP,
- In System Programmable (ISP) through the 6-pin header and a jumper, (no need external programmer),
Printer PORT ---- 89S51 / 89S52 or similar
pin 6 SCK
pin 7 MOSI
pin 9 RST
pin 10 MISO
Pin 18 - 25 GND
(TESTED)
Make your own ISP cable for the circuit board
OR
connect directly to IC on a breadboard
OR
connect on your own made IC board on general Purpose PCB]
SOFTWARE to be used :: ISP-Flash Programmer Ver3.0a available at
http://www.kmitl.ac.th/%7Ekswichit%20/IspPgm30a/ISP-30a.zip
CIRCUIT 2 (TESTED)
Circuit using Buffer 74HC541 (similar to 74HC244) compatible to STK200
6 wire interface (5 wire & a GND pin)Parallel PORT pins to be used
PIN 5
PIN 6
PIN 7
PIN 9
PIN 10
PIN 18-25
Software used :: SAME ISP-Flash Programmer ver3.0
for extra details go to
Circuit 1:
http://www.kmitl.ac.th/~kswichit%20/tahan/boards51/Board%20S51.htm
Circuit 2:
http://www.kmitl.ac.th/%7Ekswichit%20/IspPgm30a/ISP-Pgm30a.html
else contact me...
*** NOTE :: connect + VCC & GND to 8051 .....
TESTED
Basics of AVR for embedded starters..
If you are having any problem with AVR microcontroller burner ....
Not able to get one....
If your PC have a parallel port...
then..
NO need to buy any STK500 or similar....
just....
make your own programmer.....
as simple as possible ....
a) Only 5 wire interface... ( 4 basic wires & one ground cable)
using BSD programmer.....
Just connect pin no..
Parallel Port --- AVR
7 --- RESET
8 --- SCK
9 --- MOSI
10 --- MISO
18-25 ---- GND
Software Used :: AVR dude windows based programmer
b) Use a buffer / driver for the programmer (STK 200 dongle)
(click on above link for the larger image of circuit)
only one IC 74HC244 required
the circuit can be made on a bread board... or on normal PCB
Software used :: PONYPROG on the same website www.lancos.com
* circuit of AVR STK200 dongle is also available on www.electronicsforu.com
or use google search for old Kanda or ISP circuit or STK200 dongle
Both the programmers have been made & tested.
for any help contact me
