tag:blogger.com,1999:blog-8042569099194536366.post1136383633033890504..comments2024-03-15T10:26:25.870+00:00Comments on Captain Bodgit: Raspberry Pi GPIO: mixing voltage levelsSteveDeehttp://www.blogger.com/profile/10645378028590228663noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-8042569099194536366.post-82608914121862188582016-10-22T08:08:37.373+01:002016-10-22T08:08:37.373+01:00I agree. A silicon diode with a low current flowin...I agree. A silicon diode with a low current flowing through it often shows a volt drop of 800-900mV. So that fits with diode protection between gpio inputs and the 5V rail.<br />It is now over 3 years since I started "abusing" the Pi gpio, and I have not damaged any of my boards (I currently have 13).<br /><br />BTW I like your article on rebuilding a valve (vacuum tube) amp: http://www.stefanv.com/electronics/rebuilding-a-hammond-ao-29-amplifier-from-the-ground-up.html<br /><br />I need to push the rebuild of my 1950's Bush radio further up my job list!SteveDeehttps://www.blogger.com/profile/10645378028590228663noreply@blogger.comtag:blogger.com,1999:blog-8042569099194536366.post-82199278988835846582016-10-21T17:19:09.090+01:002016-10-21T17:19:09.090+01:00The sudden rise in current at about 5.8V suggests ...The sudden rise in current at about 5.8V suggests that there is an overvoltage protection diode, but that it is tied to 5V instead of 3.3V.StefanVhttps://www.blogger.com/profile/00283139131029494315noreply@blogger.comtag:blogger.com,1999:blog-8042569099194536366.post-4419581142568647272016-03-16T11:01:34.824+00:002016-03-16T11:01:34.824+00:00OK, this is a good analysis of what is probably go...OK, this is a good analysis of what is probably going on behind the Pi's GPIO pins. I've been interfacing microcontrollers to Pi's since the Pi has been on the market, and I've been using resistor voltage dividers to get 5V talking to 3.3V. I just believed the mantra like everyone else! <br />Things may change in my designs now that I've read your analysis. Thanks.<br />Steve. Stevehttps://www.blogger.com/profile/15129928208050867040noreply@blogger.com