Analog webserver response meter

If you are running webserver you probably know that one of important performance parameters is response time. In order to keep an eye on server status, Jacob have built a webserver response meter which uses servo driven analog arrow to indicate how fast requests are served. Also there are couple 7 segment led displays where time is indicated in milliseconds and current number of requests. A small 8×8 LED matrix display is used to show graphical info like happy face is everything is all right. Code runs on Arduino which accepts server data via USB interface. Host runs NodeJS application which requests data from API. Then according to response time servo is controlled to display speed gauge. Continue reading

Webserver down alarm on Tessel board

If you are running website on a server you know that many things can happen. It can go down due several reasons and you may notice this only when try to connect or load webpage. In order to avoid long downtimes you need to set up alarm which would ring bells and whistles once it goes down. Kelsey shared a website down alarm project based on Tessel board. Tessel board simply pings website every second and once trouble is detected it starts alarm which is a large red alarm light. Lamp was modified to be controlled from relay module which plugs directly to Tessel board. Speaking of Tessel boar it is an ARM processor based development board which runs entirely on Node.js. It already has built in WiFi module what makes it great tool for Internet of Things (IoT). Continue reading

Building complete webserver with Arduino, SD card and ENC28J60

Luca has been working with ENC28J60 shield. He was able to send big files including images and html pages. So no he pushed things further and built a webserver with Arduino, SD card and ENC28J60. He connected SD card module and ENC28J60 to Arduino via SPI interface. He wrote sketch that handles static data that are fetched from SD card and dynamic resources like AJAX that are handled by sketch. Files in SD card are stored by using tinyFAT library that require less RAM to work. Static resources are sent from webserver with GET method. Different approach is with dynamic content. It is rendered within Arduino sketch. In his example AJAX call is triggered every 30 seconds to update uptime on webpage. All resources are open and accessible on GitHub. Continue reading

DIY Your Very Own Home Power Monitoring System

You always want to cut off the monthly household electricity bills, but it remains a thought in your head, as you didn’t seem to make it becomes a reality! Instead of leaving the great idea sitting in your brain, why don’t you take some time and DIY a Home Power Monitoring System? For your information, this project is involving the use of current transducers, an Arduino and some custom software to monitor power consumption for your house. Normally, all the power measurements are being collected, graphed and made public on a webserver. Based on the above figure, you can see that the graph is measured in two forms: Approximate power usage and single phase. By using this system, you can measure the use of household appliances, such as lights, computer, air-conditioner, heating system, refrigerator and much more. You can also learn about how water heater warranty works. Frankly, it’s a very affordable project, as it cost less than $100. You can further save more if you’re adding a serial port to a router running OpenWrt or using a dedicated computer… Continue reading

The Digital Paperless Receipt System Will Make Your Life Easy!

If you have a job, where you’re needed to keep track of paper receipts, then it would be a disaster, if you discovered that a few of the paper receipts were missing here and there! You might be in deep trouble, especially when you’re being accused or blamed for missing the important paper receipts of company. In order to get yourself out from this mistake, you might want to develop digital paperless receipt system. By using this digital paperless receipt system, all your receipts can now be stored automatically in one central location. Well, the main purpose of this project is when a customer tries to make a purchase with a credit or ATM card; the transaction information will be automatically packaged and sent to a webserver. If the customer wants to view their transactions online, they have to log into a web interface to check on their previous transactions! The cashier uses the keypad to enter an amount to be charged. Then, it displays the amount on the LCD display. The keypad is matrix encoded, thus it can only… Continue reading