There’s an old saying: Tell me and I forget, teach me and I may remember, involve me and I learn. I’m guilty of this in a big way — I was never much on classroom learning. But if I build something or write some code, I’m more likely to understand how it works and why.
Circuit simulation and software workbooks like Matlab and Jupyter are great for being able to build things without a lot of overhead. But these all have some learning curve and often use clever tricks, abstractions, or library calls to obscure what’s really happening. Sometimes it is easier to build something in a spreadsheet. In fact, I often do little circuit design spreadsheets or even digital design because it forces me to create a mathematical model which, in turn, helps me understand what’s really going on.
In this article I’m going to use Google Sheets — although you could do the same tricks in just about any spreadsheet — to generate some data and apply a finite impulse response (FIR) filter to it. Of course, if you had a spreadsheet of data from an instrument, this same technique would work, too.
Continue reading “DSP Spreadsheet: FIR Filtering”
As weird as it might sound, there’s a way to use Google documents as a web proxy. The image above is a screenshot of [Antonio] demonstrating how he can view text data from any site through the web giant’s cloud applications. Certain sites may be blocked from your location, but the big G can load whatever it wants. If all you need is the text, then so can you.
The hack takes advantage of the =IMPORTDATA() function of Google Spreadsheet. We guess the command is meant to make import of XML data possible, but hey, that’s pretty much what HTML data is too, right? But what good it the raw webpage code in a spreadsheet? This is where [Antonio] made a pretty brilliant leap in putting this one together. He authored a bookmarklet that provies a navigation interface, hides the raw code which is stored in the spreasheet, and renders it in the browser. This ties together a user supplied URL, reloading data on the hidden spreadsheet and refreshing the window as necessary. See for yourself in the clip after the break.
Continue reading “Using Google Documents As A Web Proxy”