I’m not sure why it is but, electronic hobbyists like to make clocks. We seem to be thrust towards them like electrons to a phosphor coated screen in a cathode ray tube. Although, at a much lower velocity. Nevertheless, I somewhat recently decided it was time to make a clock for myself. I quickly came up with several ideas of the physical implementation e.g. alarm clock, ceiling projected display etc. but, as I found out that is the easy part. I was able to distill every clock design down to the need for an (acceptably [more on acceptable accuracy later]) accurate time base, most likely 1Hz and that is what this post “Part 1″ will focus on. I will attempt to offer rational explanations as to why I decided to do things the way I did because, in case you didn’t know, there are more ways to make a time base than there are numbers on a clock’s face. Here’s how I cut my teeth skinning this kitten.
Real Time Clock – [Link]
LiveGraph is a framework for real-time data visualisation, analysis and logging. LiveGraph was developed in the academic domain and is being used for research on daily basis. Being open source, LiveGraph is absolutely free. LiveGraph particularly useful for all applications that require live visualisation of large amounts of data in form of graphs and charts.
LiveGraph – [Link]
Simon Inns created a secure USB time stamp device: [via]
This project implements a USB device which provides a real-time clock for the purpose of time-stamping events in an non-networked embedded computer environment. For embedded applications where a periodic time-stamp is required (such as entry-system logs, configuration audit logs, etc.) it is necessary to have a fairly accurate real-time clock (better than that typically provided by a PC’s motherboard) to generate time-stamps in logging and audit trails. Furthermore, it is preferable to have a method of confirming that the log/audit files have not been tampered with in anyway. The secure USB time-stamp device solves many of these issues in a very small form factor using minimal components .
Secure usb time stamp – [Link]
A common challenge when working with embedded systems is keeping track of real time. Luckily, most microcontrollers have timers that can be used with a precision quartz crystal — already present for the CPU clock — to keep track of real time. In this video tutorial, we show how you can use the timer interrupts on an ATMega168 chip to make a simple timer. Building off of this, it is possible to make your own reasonably accurate alarm clock, create systems to perform timed automated tasks, or create a multitude of other projects.
Crystal Real Time Clock – [Link]
Atanua is a real-time logic simulator, designed to help in learning of basic boolean logic and electronics. It uses OpenGL hardware-accelerated rendering and a custom UI designed for a fast workflow and a very low learning curve, letting the students concentrate on learning the subject instead of spending time learning the tool.
See the interactive flash demo!
Atanua – Real-time logic simulator – [Link]
This a custom designed module for the DS1307 Real Time Clock. The module comes fully assembled and pre-programmed with the current time (ok, so it’s our current time – MST). The included Lithium coin cell battery (CR1225 41mAh) will run the module for a minimum of 9 years (17 years typical) without external 5V power. The DS1307 is accessed via the I2C protocol. We’ve written a test-bed to program the modules. This test-bed code should give you some insight on how to interface the module to any mircocontroller using our example software I2C and BCD routines.
Real Time Clock Module – [Link]