Radio, Electronics and Computing Projects by Hans Summers
I make no claims for technical accuracy, good design, or necessarily even originality for the contents of these pages. Rather, I am a simple enthusiast attempting to convey my love and enjoyment of radio, electronics, and computing and perhaps to inspire YOU to build something too. The following pages document projects that I have built over a period of 30 years. Wherever applicable I have named sources and references. In each project I have attempted to provide as much information as time and resources allow, but no responsibility can be accepted for inaccuracies or omissions. Likewise, where some of the projects use mains or high voltages, no responsibility can be accepted for death or injury sustained if you attempt to replicate these projects. BE CAREFUL! If you have any comments or suggestions, please email me. Due to the popularity of these pages and the increasing expense of web hosting and bandwidth, it has been necessary to include advertising on some pages to cover my costs.
GSM/GPRS Data logger
Written by Hans Summers
Thursday, 29 December 2011 11:45
GSM/GPRS Data logger, which can measure analogue or digital inputs, cache them in memory and upload them via the GSM/GPRS network to an internet database, send via email or SMS, etc. Email me.
The Si570 is a relatively new device made by Silicon Labs. It's a very small device containing a crystal reference oscillator, digital Phase Locked Loop (PLL), and I2C interface so it can be programmed for any frequency between 10MHz and 945MHz (selected frequencies to 1.4GHz). Direct Digital Synthesis (DDS) chips such as those from the market leader Analog Devices have been around for longer. They are very different kinds of parts, even though they are both oscillators. Accordingly the best choice depends heavily on the application. These are my opinions about the relative advantages and disadvantages which may be important factors for your decision.
This page documents the beginnings of my work on a transmitter I'm going to name "Hellraiser". Ultimate idea: Feld-Hell on 20m. The valve is a massive TB4/1500 and I'm using a microwave oven transformer as a filament power supply.