tag:blogger.com,1999:blog-28344720.post2301017592623996954..comments2024-02-21T06:47:29.430-07:00Comments on Chip Overclock<sup><small>®</small></sup>: DTMF Tones, Fourier Transforms, and Spectral AnalysisChip Overclockhttp://www.blogger.com/profile/11195242013008369733noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-28344720.post-90674538914886900392014-02-25T08:28:23.424-07:002014-02-25T08:28:23.424-07:00I miss the days when it was that simple. Now it se...I miss the days when it was that simple. Now it seems like you end up using an expensive digital signal processor with thousands of lines of code just to do tones. Of course, it can do lots of other stuff too (like tone detection). But for just generating DTMF down an analog channel, it's like using a "physics package" (just learned that term) to hunt rabbits.Chip Overclockhttps://www.blogger.com/profile/11195242013008369733noreply@blogger.comtag:blogger.com,1999:blog-28344720.post-73173647301748178752014-02-21T10:54:20.773-07:002014-02-21T10:54:20.773-07:00Very nice. You should check out the LM567. It is t...Very nice. You should check out the LM567. It is the original tone decoder chip. One chip per column/row. http://www.ti.com.cn/cn/lit/ds/symlink/lm567.pdf<br /><br />I built a set of touch free infrared through the glass buttons with these. Each button was tuned to a different frequency so they would not interfere with each other.<br />Cool little part.Doughttp://www.embeddedapprentice.com/noreply@blogger.comtag:blogger.com,1999:blog-28344720.post-15529428813216271342014-02-14T16:11:25.024-07:002014-02-14T16:11:25.024-07:00When Touch-Tone was first introduced, I dimly reca...When Touch-Tone was first introduced, I dimly recall that you had to pay extra to get it. That lasted until all the central offices were equipped with enough tone detector hardware that they could handle the maximum engineered simultaneous digit collection load. Then the phone company(s) changed to charging more for pulse dialing, because they wanted to eliminate the pulse digit collection Chip Overclockhttps://www.blogger.com/profile/11195242013008369733noreply@blogger.comtag:blogger.com,1999:blog-28344720.post-57945759632073739752014-02-14T15:11:46.207-07:002014-02-14T15:11:46.207-07:00This is wonderful. I've always enjoyed the his...This is wonderful. I've always enjoyed the history of telecom. We had a rotary phone when I was a kid - I liked it better than the push button one, and as an adult wish I'd kept it... <br /><br />As a side note, I wanted to name our cats Tip and Ring after I worked in a phone shop as a maintenance tech, but nooo.bookwenchhttps://www.blogger.com/profile/08791403451040847457noreply@blogger.comtag:blogger.com,1999:blog-28344720.post-53459479677443957832014-02-14T05:03:10.170-07:002014-02-14T05:03:10.170-07:00Great article. Maybe as I get more senior myself ...Great article. Maybe as I get more senior myself I appreciate history more. <br /><br />I've heard the terms tip and ring for many years, including when I managed a Network Services group for six years, but thought they were obscure references to telephony functions, not to the physical components of a patch cord. Even more useful will be understanding the 3.5mm plugs on my headsets and Paul Moormannoreply@blogger.com