**** BEGIN LOGGING AT Thu Jun 27 02:59:57 2019 Jun 27 03:21:38 set_: I added another version of the same schematic (to the same album) that is easier to understand, at the expense of not showing the actual physical pinout of the level shifter Jun 27 03:21:49 Okay. Jun 27 03:22:11 @zmatt: I made some oops and mistake notes on the google thing you posted. Jun 27 03:22:17 and please just use chat, not comments on the photos Jun 27 03:22:23 Got it. Jun 27 03:22:34 No issue at all. I will use just chat. Jun 27 03:23:13 and if you swapped vcc and vdd then you're lucky if you didn't destroy the bbblue or at the very least that pin of it Jun 27 03:24:13 I understand. Jun 27 03:25:09 I will have to see if that pin is still good after all this back and forth. Jun 27 03:25:54 you may want to verify whether the E4.4 pin still works by configuring it to gpio mode (as input) and confirming it reads back correctly when you pull it up (to 3.3V) vs down (to GND) with an external wire Jun 27 03:26:10 Okay. Jun 27 03:27:20 @zmatt: Why do I need so many pins from the CD40109B? Jun 27 03:27:40 If you have time, answer. If not and if it is too intricate to explain, I understand. Jun 27 03:27:40 because inputs shouldn't be left floating Jun 27 03:27:45 Oh. Jun 27 03:27:46 Nice. Jun 27 03:28:10 Is that a general rule? Jun 27 03:28:24 it doesn't really matter whether you connect the unused inputs (B, C, D, and their ENABLE pins) to GND or VCC, at long as you connect them to one or the other Jun 27 03:28:58 Okay. Jun 27 03:29:01 yes, unless you're sure the device is okay with leaving them unconnected (for example because it has internal pull-ups or pull-downs on the inputs, like the beaglebone does) Jun 27 03:30:17 Aw...so like w/ small devices like this CD40109B, there are no pull-up/down resistors in it and that is why it is smart to get them "situated." Jun 27 03:31:02 doesn't really have much to do with "small" or not Jun 27 03:31:20 Oh. Okay. I guess I have not come across this instance before. Jun 27 03:31:35 But...I can see why this is a good, general rule. Jun 27 03:31:35 I mean, you probably have but just ignored it Jun 27 03:31:48 Most likely. You are right. Jun 27 03:32:07 leaving digital inputs floating can cause excessive current and power consumption, and may damage the input in the long run Jun 27 03:32:50 Like wires in a house that keep feeding elect. to the ends when not in use (bare wires)...like this idea? Jun 27 03:33:00 ... no Jun 27 03:33:02 No? Jun 27 03:33:33 Okay. Jun 27 03:33:45 No issue if you do not want to explain. Jun 27 03:33:52 I don't even understand what you're trying to say... wires that "keep feeding electricity to the ends when not in use" don't consume power Jun 27 03:34:14 Oh. Jun 27 03:34:36 (or negligible power anyway) Jun 27 03:35:20 Hmm...I guess bare wires are just an issue in general b/c of their tendency to arc. Jun 27 03:35:27 Like that? Jun 27 03:36:02 I'm done for today with trying to understand what you're saying Jun 27 03:36:08 Hahhaha. Okay. Jun 27 03:36:18 No issue. I should have been in bed about two days ago. Jun 27 03:37:12 For what it is worth, thank you for your input and the diagram(s) on the CD40109B. Jun 27 03:37:38 I can really use this idea and those diagrams to test things for making BBBlue a flight case. Jun 27 03:37:48 Peace! Jun 27 10:17:37 I've done this with a raspberry : https://github.com/JamesP6000/WsprryPi can it be done with a beaglebone also ?? Jun 27 10:31:12 do you expect people to first study some random project in order to determine what it does exactly and therefore what your actual question is? Jun 27 10:37:54 it sounds like their specific implementation is highly specific to the hardware used (i.e. the rpi), but the am335x also has all sorts of features that could be (ab)used to generate all sorts of signals (e.g. pru, optionally with pruss clocked by the display PLL to be able to fine-tune its frequency) Jun 27 10:38:19 the specifics obviously depend greatly on the exact signal to be produced Jun 27 11:09:13 * tbr wouldn't want to operate such a thing without a very good band-pass filter Jun 27 11:09:33 yeah it sounds gross as hell Jun 27 11:14:23 zmatt reminds me of someone using the output of there VGA card to modulate NTSC RF signals and video to their TV like 20 years ago. Jun 27 11:16:07 there are USB-3 attached RAMDACs nowadays, sold as USB-to-VGA converters :) Jun 27 11:16:24 same thing applies Jun 27 11:17:19 "please shoot the designer and put them out of our misery." Jun 27 11:39:02 sanjiv37: STOP sending me unsolicited private messages **** BEGIN LOGGING AT Thu Jun 27 11:54:12 2019 Jun 27 14:32:11 zmatt: of course not, but I know some people on this channel ;) It can recognize things at a glance ...... Jun 27 14:34:35 I mean there are few projects for rpi that can be copied directly into a BB , just to know if this one can be doable (or one can take time to modify and adapt it to BB) Jun 27 14:36:20 there's not really an "at a glance" possible here, it requires careful analysis of the desired waveform vs the capabilities of the am335x, and almost certainly will require some experimentation (e.g. to determine whether the display PLL can be modulated in the way required for this) Jun 27 14:40:23 ok. Jun 27 14:40:39 also keep in mind that, as the README points out, you'll need an external filter and a HAM radio license Jun 27 14:53:32 having both ;-)) Jun 27 14:53:40 ok, good :) **** ENDING LOGGING AT Fri Jun 28 02:59:57 2019