Five Ways to Improve Your Website

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Khoa Bui, On Friday 22 July 2011, 15:40 SGT

Have you ever visited a website and closed it within a few seconds? There are many reasons why people do this. A guest may want exit your website if it:

• Takes too long to load
• Doesn't look like it relates to what they're searching for
• Doesn't load correctly
• Is too cluttered
• Is too empty

As a small-business owner, why would you invest thousands of dollars in building a site if visitors just tune out?

Solving click-off is one of the biggest challenges I discovered while building thousands of websites for clients as a website designer. If a visitor comes to your website and leaves within eight seconds, you need to fix something. Here are five fast ways that I've used that dramatically minimize click-off by improving your website's performance, speed, search engine results and relevance for users.

1. Speed up your website.
When your site doesn't immediately grab visitors' attention and inspire them to take action, you're wasting leads who could have become long-term customers.

One culprit for visitors quickly leaving your site may be a slow-to-load home page, and one of the biggest contributors to a slow-loading website is large, high-resolution images. Large animated Flash files can also weigh down a site's loading time.

Related: Five Time-Saving Tips for Updating Web Content

To fix this issue, consider putting fewer images on your home page and no Flash at all. You can also ask your web designer or developer to optimize your current images by compressing them and lowering the resolution.
One easy way to test the speed of your website is to view it on a slow Internet connection. Don't have access to a slow connection? Search online for "website speed test" for free tools to test the speed of your site.

Another issue to consider is whether your web host is slowing you down. Before you pay for a host, research reputable companies known for fast, high-quality connections.

2. Bold keywords.
Search engines want to provide relevant results on websites with high-quality content. That makes it critical for you to provide the most relevant, high-quality information your target market will be searching for. One way to quickly connect visitors to that great information is to bold the most important keywords.

For example, if someone finds your site by searching "cycling in Perth," make sure your website has the keywords "cycling" and "Perth" in bold type. I'm not suggesting that you continually bold all your website keywords. Just bold one or two keywords close to the top of your web page.

3. Tag your graphics.
Another way to attract more traffic is to optimize your graphics so they become more visible to the search engines. Many entrepreneurs don't realize how much they can benefit from being listed in the Google Images database.

So how do people find you when they search for images? It's easy. When building your website, make sure your web designer includes the correct coding to hook your images with relevant keywords. Name your image files with relevant, descriptive words and include a title tag and an alt tag in your image code. These tags allow you to include more information and keywords related to your image. By including these elements, search engines will be able to understand the content of your images and it will make your site more accessible to visitors with visual disabilities.

Related: Making the Most of 'Contact Us' to Gather Leads

Make sure you don't keyword-stuff that code, though. Search engines will know you're trying to cheat the system, and you'll run the risk of becoming banned from their listings. Just describe the images in natural language without repeating words.

4. Update your website dates.
When your website has the current date, it's basically telling visitors that this website is up to date. It's fresh and current. Search engines know this and take it into consideration. After all, search engines want to provide the best possible results.

If you visit a website and scroll to the bottom and see "Copyright 2005," you might think that was the last time the site was updated. Outdated information makes the site look neglected and unprofessional.

5. Comply with online quality standards.
In a nutshell, W3C compliance is an online standard, or set of rules, that, when followed, ensures your website adheres to a strict quality standard. (W3C is short for the World Wide Web Consortium, the main international standards organization for the Web.) When you create your site according to these standards, it tells the world you care about quality and taking good care of your site.

Some of the coding differences can seem miniscule and tedious -- for example, remembering to include a slash at the end of a line of code -- but my own experience as a web designer showed me that when I make the extra effort to follow these standards, my site earns better rankings. If you are not building your own site, make sure that your web developer is applying W3C compliance to all of your website work.

Related: Five Things You Should Know About Web Analytics

 

This article originally posted on Entrepreneur.com

Tutorial - SPI interface

SPI Interface or Serial Peripheral Interface bus is as you might expect a serial interface meaning data is shifted out (and in) one bit at a time.


It is intended for transmission of data from a master device to/from one or more slave devices over short distances at high speeds (MHz).

It is simply based on an 8 bit shift register shifting data out on a single pin and shifting data in on another pin.

Note: some devices use more than 8 bits!



 
Its main use is to replace parallel interfaces so you don't have to route parallel buses around a pcb.  For example you can buy an SPI 12bit ADC and instead of 12 parallel wires to read the data you only need 4 SPI connections.  Actually you may only need three as you may not need to send data to the device!


 With the SPI interface you can communicate with a device transmitting and receiving 8 bits of data at the same time and it is suited to high speed streaming data transfers.

Note: The trade off between using a parallel interface and the SPI interface is speed e.g. if you read a parallel 12bit ADC at 200ksps then you could read the device at a 200kHz rate but if you want to get the same data rate using SPI then you need a serial speed of 200kHz x 12 = 2.4MHz.  So the actual trade off is speed and the consequential noise introduced into the circuit.


Unlike I²C there is no concept of transferring ownership of the bus i.e. changing bus master and there are no slave device addresses.  SPI is a much simpler protocol and because of this you can operate it at speeds greater than 10MHz (compared with the 3.4MHz maximum for I²C).

The best feature of SPI is that you can do full duplex data transfers (data in both directions at the same time) which you can not do with I²C and you can do it fast.

Note: The maximum rate for a PIC Micro using a 20MHz clock is 5MHz.

SPI Interface : Signals

SPI Interface Signals
PIC name	Master	Slave
SCK	Serial clock output from master [SCK]	Input to slave [SCK]
SDO	Serial data output from master [MOSI]	Input to slave [MOSI}
SDI	Serial data input from slave [MISO]	Output from slave [MISO]
SS	Optional slave (chip) select [SS]	Slave select [SS]

[] denotes SPI naming convention

Here is the setup for a single SPI device connection:

SPI Interface - single device

Note: The chip select signal SS is optional for a single device system as you could tie the SS input at the slave low if the other lines are dedicated to SPI use.

There are two ways to implement multiple slave operation:

• Use a separate chip select for each slave device.
• Wire all the slaves together DataOut to DataIn (daisy chain).

SIP Interface : Using chip selects

SPI Interface using separate chip selects

With this scheme you control each slave device using its chip select line (usually active low- red arrows show control lines).  When disabled the Data output from the slave goes into a high impedance state so it does not interfere with the currently selected slave and the data input is ignored (check datasheet).

The advantage of this scheme is that you can consider each device separately when you compare it with the daisy chain method.

SPI Interface : Daisy chaining

With this scheme all data sent by the master is shifted into all devices and all data sent from each device is shifted out to the next (shown by red dotted arrow).  For this scheme to work  you have to make sure that each slave uses the clock in the same way (see clock and data) and you have to get the right number of bits - so there is more work to do in software.

Compared to I²C these are very inelegant slave selection mechanisms and look like kludges to get round the fact that SPI was designed really as a simple single master to single slave protocol.  Having said that the above methods will work but for daisy chaining you will have to be careful of clock polarity and clock use as this is not defined in the SPI standard.

SPI Interface : Clock and Data

How a device reacts to clock input is undefined!!!

Data can be sampled at the rising or falling edge and data can be generated after the rising or falling edge!

This is why you can set the clock output from a master mode device in multiple ways just look at the diagram below - the first four signals are the four options you have to select the output clock.

SPI Interface PIC signals (extract from DS39582B)

You match the output clock to the clock that your device requires.

Note: This is why daisy chaining may not be a good idea (or you have to think very carefully about it!).

Note: For Master or Slave mode when using PICs you need to set the TRIS direction of the SCK pin appropriately.

Problems with the SPI interface

• The clock scheme may not be the same between devices.
• The data length can vary from device to device.

Advantages of the SPI interface 

• Very fast > 10Mhz.
• Simple protocol (easy to program in software if you have no SPI hardware module).
• Simple interface (no bidirectional pins c.f. I²C).
• Supports full duplex data streaming.

 
 
 
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Pan Tilt (possibility)

Compact Gimbal Mirror Mounts

STOCK# CCGM-1 CCGM-2
Optics Diameter: Ø mm( Inch ) 25.0(1”) 50.0(2”)
Optics Thickness: Min mm( Inch ) 3.0(0.12) 3.0(0.12)
Adjustable Axis θx , θy
Travel Range ( θx , θy) ± 4゜
Dive type 100 Pitch screw
Weight (kg) 0.16 0.25
Material (Treatment) Aluminum ( Black anodized )

Motor Control - What is Four Quadrant Control?

What is Four Quadrant Control?

Hardware: Motion Control

 
Problem: What are the four quadrants of operation of a motor drive? How does this apply to my motion control system?


Solution: To answer this question, we must understand a little about the purpose of servo motors and their function as an electromechanical conversion device. Servo motors are differentiated from other types of electric motors by the fact that they are typically designed with an emphasis on smooth, accurate position and/or velocity control, rather than ultimate power output. Servo systems are often bi-directional (CW or CCW), whereas many common industrial motor drives for pumps and fans and similar equipment only operate in one direction. Accurate control of acceleration and deceleration of a motor is another characteristic of servo systems, which is not always found in simple motor control systems. Many motors rely on the friction alone to decelerate the load when power is removed.

If we consider both directions of operation (CW and CCW) and both modes (acceleration and deceleration), we arrive at four distinct areas, or quadrants, of operation. This can be visualized by plotting the velocity of the motor on the X axis of a graph and the direction of applied torque on the Y axis as shown below. Quadrants 1 and 3 represent the motor applying torque in the direction of motion, while quadrants 2 and 4 represent applying torque opposite the direction of the motion. In quadrants 1 and 3 the flow of energy is from electrical to mechanical. The servo motor is converting electrical power from the drive into motion in the system. In quadrants 2 and 4, the motor is actually acting as a generator. The motion of the system is being converted into electrical power, which is then absorbed by the drive.

Some motor drives are capable of operating in only quadrant 1, while others will work in quadrants 1 and 3, quadrants 1 and 4, etc. Since most servo drives are designed for accurate control in both directions, many will operate, at least transiently, in all for quadrants. To do this the drive must be able to both source and sink electrical power from the motor.





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iPhone Credit Card Reader