**** BEGIN LOGGING AT Thu Feb 04 03:02:58 2021 Feb 04 03:03:05 I think the BELA Cape and Replicape may be handy for this project. Feb 04 04:26:55 acrylics or very stiff plastics make good acoustic devices. Acrylics aren't amenable to standard 3d printing and they have a very strong odour when curing. Feb 04 04:27:36 Nice! Feb 04 04:27:54 They might be usable as a resin plastic and UV layer curing. Again that would be complicated and too make it large enough would be somewhat challenging. Feb 04 04:28:19 are you familiar with how LCD's are produced? Feb 04 04:28:53 No sir, not at all. Feb 04 04:30:41 I will brb. Sorry. Call of the smiles. Feb 04 04:30:57 an LCD is a light valve, they have a material that when energizes polarizes and blocks light from passing through. Your typical 1920x1080 LCD is actually 5760 horizon valves by 1080 valves. Feb 04 04:34:18 Nice. Feb 04 04:34:28 Hmm. Feb 04 04:34:39 Filled w/ what? Feb 04 04:34:56 I remember those gas filled TVs. Feb 04 04:35:16 I think they call them Plasma or something. Feb 04 04:37:49 You know something... Feb 04 04:38:33 Thinking of kits here. Making a kit to turn boxes, metal and/or plastic, into an instrument sounds nifty. Feb 04 04:39:32 I should try on my older metal box. Like w/ BELA, I could do so much w/ addin' in pots and other ideas. Feb 04 04:39:58 Now, I am sure this exists already. What has not been done? Feb 04 04:42:47 Anyway GenTooMan, i know you are working on LCD stuff. SOrry to bore you. Feb 04 04:43:19 I just found a funny site and guess what it is called, i.e. yes and it is called GuitarKitWorld.com. ha. Feb 04 04:43:38 Big names, same dames. Feb 04 04:45:27 03:02 For anyone interested in 3D Printing and Violins: https://openfabpdx.com/product/modular-fiddle-printed-parts-kit/. I think the fellows at the BELA Cape may respect this project. Feb 04 04:45:28 03:03 I think the BELA Cape and Replicape may be handy for this project. Feb 04 04:45:28 i LOVE the Bela project. i'm very interested to hear more about your work. Feb 04 04:46:51 ullbeking: That is not me. That was some random person working on making his reality a reality. Feb 04 04:46:56 He seems good at it too! Feb 04 04:47:26 I am like a null pointer. Feb 04 04:47:28 I saw someone make a guitar out of old iPhones which, seemed kind of silly but hey. Feb 04 04:47:39 Right but can he jam? Feb 04 04:47:58 Actually I know a person whose last name is actually Null. which apparently caused him trouble when he went to school. Feb 04 04:48:09 Heh? Me? Feb 04 04:48:10 Ha. Feb 04 04:48:36 The school data base apparently wasn't Null sanitized properly and the system crashed with his name. Feb 04 04:49:09 la la la...Blah. Feb 04 04:49:11 Ha. Feb 04 04:49:29 THey called for me again and again globally. Feb 04 04:49:42 anyhow I could ask my brother about the web page. He is a guitarist (ex professional didn't pay enough). Feb 04 04:50:01 Right. You have to act real funny in that field to gain attention. Feb 04 04:50:16 Pro Guitarist! Nice. Feb 04 04:50:37 I am skillless if that was a word. Feb 04 04:50:48 You have to one be very lucky and two have the right people to help you. Otherwise you are just in some ambitious twits way. Feb 04 04:51:08 Right. I am ambitious still w/ a heart to break, too! Feb 04 04:51:10 Ha. Feb 04 04:51:11 Very vicious the music business. Feb 04 04:51:32 I bet. I know nothing about music and musicians' views. Feb 04 04:51:44 Hey! Feb 04 04:52:56 GenTooMan: W/out thinking of my next line, I would like to say this now. Feb 04 04:53:34 After reading a bunch, I found there is more to life than just digging deep from the US to China. Sometimes things are as shallow as can be in life. Feb 04 04:53:50 I mean no harm. Feb 04 04:54:20 But, I love fun. The BBB and you all have been more than fun, e.g. even though you may not like it. I have enjoyed my stay. Feb 04 04:54:54 Now! LCDs and the BBB? Feb 04 04:55:08 Where are you in your venture, sire? Feb 04 04:56:05 Oh and I maybe found a person that can print this violin! Feb 04 04:56:11 Neat, heh? Feb 04 04:57:03 My 3D Printer is only 6 cubed of a workspace. So, violins are out for me. Feb 04 04:58:27 * set_ is small time. Feb 04 05:07:58 depends on the material you wish to use basically. Feb 04 05:08:51 Yep. Feb 04 05:09:13 I was reading about heat treating specific plastics. Feb 04 05:09:17 The most likely method is to make a mould for the guitar body and then cast the thing. You can create a positive mould by building sections of the body and putting them together like blocks. Feb 04 05:09:51 The issue is that the connections rattle and send "resonance" via shimmering. Feb 04 05:10:21 Like a rusty, old toolbox w/ parts in it. Sounds a bit classical but rough nonetheless. Feb 04 05:10:28 guitar bodies are made a specific way for a reason. Feb 04 05:10:38 Oh. Feb 04 05:11:05 I always thought they were made in those particular manners for a comfortable setting. Feb 04 05:11:31 Sitting and picking has to be comfortable, right? Feb 04 05:12:50 * GenTooMan head tilts and whines like a dog. Feb 04 05:12:59 Argh and hoo! Feb 04 05:13:14 I know what you are asking yourself! Feb 04 05:13:30 Well, do ya? Feb 04 05:13:31 ha. Feb 04 05:14:05 Every time I chat w/ you, I cough. It is so odd. Feb 04 05:14:07 set_ maybe you should visualize the structure of a classic acoustic guitar first? Feb 04 05:14:30 Look, matey. I am onto violins. Plastic Violins at that! Feb 04 05:15:05 I may get someone to produce the singing wheeper for my own use. You know, for testing. Feb 04 05:15:55 Then, once the plastics are done, bam! I am going to add the BELA. Feb 04 05:16:02 w/ some pickups! Feb 04 05:17:17 I can cut plastics. I just need to have the body and neck done. I could repeat that line day, "body and neck!" Feb 04 05:17:40 putting a audio transducer on a violin is kind of tricky I've found. Feb 04 05:17:46 WHy? Feb 04 05:17:59 Why is putting an audio piece on the violin so tricky? Feb 04 05:18:08 for example if you put it on the body you get a different sound than if you aim it at the centroid of the body. Feb 04 05:18:33 Oh. Yea. It is going to be on the body from what I have seen, I think. Feb 04 05:18:59 Hmm. So, one would sound one way while the other addition would be sounding different. Feb 04 05:19:01 I've added audio transducers to a few violins (sarcasm). Feb 04 05:19:11 Do you mean many? Feb 04 05:19:16 So yeah... concerts are a pain. Feb 04 05:19:24 Ha! Feb 04 05:19:34 I was conversion. Boo! Feb 04 05:19:35 really a pain I mean you hurt after all the work. Feb 04 05:19:52 I used to get free concerts. That is about it. Feb 04 05:20:12 Well, that and pay. But pay, blah. it gets spent. Feb 04 05:20:16 so anyhow you have to point at the acoustic centre of the violin to get the best sound without touching the body. Not an easy trick. Feb 04 05:20:29 Wha? Feb 04 05:20:42 So, it needs to be floating? Feb 04 05:20:46 as I said I've done a few concerts with full orchestras. Feb 04 05:20:55 I do not understand obviously. Feb 04 05:20:56 Oh. Feb 04 05:21:22 What about the English Celtics women? Feb 04 05:21:51 Anyway, forget that question. Feb 04 05:22:11 how would I plant a "transducer" on the violin w/out it being on the body? Feb 04 05:22:33 Well anyhow you have seen the suspension microphones those work OK. Their are a number of things to know. However if you just want sound you could put the microphone in a dampened area in the body if you don't care how it looks. Basically the body transmits sound but you don't want that sound you want the sound it makes when moving the air around it not in the body. Feb 04 05:23:03 Ha. Okay. Feb 04 05:23:05 I got you. Feb 04 05:23:21 So, the sound is the reverberation/cries it makes. Feb 04 05:23:43 I need to harness the reverb and cries. Feb 04 05:24:43 But how would one do that easily? All I have seen is the screws attaching to the electric instruments and strings being around. Speaking of strings, literally. Feb 04 05:25:31 Outside of floating... Feb 04 05:25:41 or attached by... Feb 04 05:25:42 Oh! Feb 04 05:25:53 So, a box in a box? Feb 04 05:26:20 Perhaps you should look up "guitar pickups" and how they work first. That's one way to get sound from it. Feb 04 05:26:42 Right...pickups. That is where I am coming from in this idea. Feb 04 05:27:32 So, I should study transducer instead of pickups is the idea? Feb 04 05:29:01 mangnetic! Feb 04 05:32:28 piezoelectric for violins! Feb 04 05:32:47 That are the types of pickups for violins, supposedly. Feb 04 05:33:38 magnetic transducers picks up fluctuations in a magnetic field a piezo transducer picks up fluctuations in force. Feb 04 05:33:56 My first 25 sentences state that piezoelectric magnitizing sensors are what the pickups...Oh. Feb 04 05:33:59 Force. Feb 04 05:34:01 Got it. Feb 04 05:34:13 Hmm. Feb 04 05:34:19 That makes sense. Feb 04 05:35:16 So, the stronger the bow presses against the string, violin stuff, the pickup (piezoelectric) handles it accordingly. Feb 04 05:35:34 Forcible Playing w/ piezos! Feb 04 05:35:42 um right anyhow Feb 04 05:35:46 Ha. Feb 04 05:36:01 Yes? Feb 04 05:37:16 anyhow piezo sensors come in 2 groups one generates a charge and the other is called peizo resistive which changes it's resistance. Most sensors used in MEMS are the latter. Feb 04 05:37:29 Oh. Feb 04 05:37:39 Okay. So, I will need a force transducer. Feb 04 05:37:47 the charge based ones are the type used in lighters that create a spark. Feb 04 05:38:24 Materials? Feb 04 05:38:41 I was thinking of wicks. Feb 04 05:38:51 well your typical tire pressure gauges are peizo resistive. Feb 04 05:38:58 Aw. Feb 04 05:39:02 That makes sense. Feb 04 05:39:12 I get that idea. Feb 04 05:39:16 Push and pull. Feb 04 05:44:42 . Feb 04 05:44:43 need to sleep myself. Feb 04 05:44:54 Okay. Later mate. Feb 04 13:53:05 Hello Guys, I have a case during abnormal boot. I am writing around 60 files into disk using node runtime and validating all the files are written without any issue and printing one of file details using stat command. I see all the files are written ok and I see file content for about 60 bytes. After doing all these, If I unplug the power and went Feb 04 13:53:06 back to check the file content I see zero even though access, create and modify timestamp are same. Can anyone please help on this to come out the situation? Feb 04 13:54:36 umm you didn't unmount the system or flush it did you? Feb 04 13:54:45 use fsync Feb 04 13:55:35 GenTooMan: unmounting the root filesystem? :P Feb 04 13:55:58 zmatt, LOL well yeah that could be interesting (hmm) Feb 04 13:56:43 Raj32: https://www.npmjs.com/package/crash-safe-write-file Feb 04 13:57:20 How can I unmount? I am using fs.writeFileSync library only because it is the standard library otherwise how can i access it? Feb 04 13:57:53 the "Sync" in writeFileSync refers to nodejs blocking instead of using a completion callback, it does not refer ot the use of fsync Feb 04 13:58:43 (generally speaking you should avoid this since it prevents other javascript code from being able to run at the same time) Feb 04 14:00:05 I tried writefile as well, and verified the same in the callback. Behaviour is same. Feb 04 14:00:28 the standard filesystem library has an fsync call but it acts on a file descriptor so it can't be used with the writeFile convenience wrapper... if you want a quick and simple solution, use an existing module like the one I linked to Feb 04 14:02:12 note btw that regardless of how you write files, power loss while writing to multi-level NAND flash (like that inside typical SD cards and typical eMMC) can result in filesystem corruption Feb 04 14:04:43 Thank you @gen Feb 04 14:05:50 Thank you GenTooMan and @zmatt . Let me try crash-safe-write-file and see how it goes. Feb 04 14:06:19 @zma Feb 04 14:09:07 zmatt my application verifies all the files are written correctly then only alerts successfully saved. so if it is not corrupted my file system then it is ok. Feb 04 14:09:28 filesystem corruption may prevent the system from even booting Feb 04 14:10:02 and you don't verify the file has been correctly written, you're just reading them from disk cache Feb 04 14:10:59 also, once the file has been written using crash-safe-write-file or any other method that uses fsync you can reasonably assume it has been written correctly; the concern is what happens if power is lost *during* this Feb 04 14:11:17 reading the file after writing it provides no useful validation Feb 04 14:12:34 zmatt so what is the solution for that;D ? Feb 04 14:12:53 I just told you Feb 04 14:13:08 15:10 <@zmatt> also, once the file has been written using crash-safe-write-file or any other method that uses fsync you can reasonably assume it has been written correctly Feb 04 14:13:30 zmatt I am thinking if anything after I confirm then it is fine. That is what I can do as of now until I find a better solution. Feb 04 14:15:04 if anything goes before that, meaning in between, it is known case, that can be communicated to the user. Feb 04 14:15:28 crash-safe-write-file ensures that 1. once it has completed, the file will have the new contents even if subsequent crash or power loss happens 2. if a crash of power loss happens while writing the file, the file will either have the old contents (if it already existed) or the new contents, it will never be partially written or otherwise damaged Feb 04 14:15:35 Hello Gentlemen, I am having an issue with an X-15 and wifi-usb dongle. When plugged in to the single port, it is not recognized by kernel time to time. When plugged into the dual USB port it is not recognized almost all the time. Based on what I have read, It might by a problem of the signal integrity.  Is there a way how to force the X15 to work Feb 04 14:15:35 in usb 2.0 mode all the time ? Or can you recomend any reliable wifi-dongle ? Feb 04 14:16:19 Thank you again zmatt. You guys are giving me a hope most of the times. Feb 04 14:16:51 zmatt ok for crash-safe-write-file update. Feb 04 14:16:58 Raj32: both of these guarantees however are still not completely true in case of power loss if the files are stored on eMMC or SD card Feb 04 14:17:32 (this is because powre loss while writing to MLC NAND can corrupt unrelated data that wasn't even being written) Feb 04 14:18:28 zmatt - ok(y) Feb 04 14:19:22 that's why nand based storage devices should have enough capacitors to complete whatever they're doing in case main power goes away Feb 04 14:19:57 mru: do they, in reality? Feb 04 14:20:05 some try, at least Feb 04 14:20:33 modern managed NAND may even keep stuff in write cache unless notified by the OS that power is going to go away (which it won't in case of power loss) Feb 04 14:21:55 magnetic hard drives also have ram cache Feb 04 14:22:59 sure... I should have phrased that better: I'm not sure how the NAND would even know it has to quickly finish writes in progress (and not start new ones!) when power loss is happening Feb 04 14:23:11 since it probably won't know unless it's already too late Feb 04 14:23:25 monitor supply voltage Feb 04 14:24:27 which is typically higher than the operating voltage of the actual chips Feb 04 14:24:54 if it starts dropping, assume you have a few milliseconds left and dump any unwritten data Feb 04 14:25:38 normal buffered writes are ok to simply discard Feb 04 14:26:36 I guess... dunno, I find it hard to estimate what kind of intelligence to expect, especially from cheap managed NAND... there's no way to tell what these things are doing internally; and at least for eMMC, there's an OTP setting for whether the integrity of unrelated data (i.e. that not being written to) is guaranteed if power loss happens during write, and this setting is disabled by default Feb 04 14:27:26 a friend of mine used to work at toshiba doing ssd controller software Feb 04 14:27:55 that sounds like it's a bit fancier than a low-cost eMMC though :P Feb 04 14:28:10 yes, emmc is probably less reliable Feb 04 14:28:20 sd cards less still Feb 04 14:28:25 I mean, you've got all sorts of eMMC and SD cards Feb 04 14:28:32 fancy eMMC will also have SMART status and such Feb 04 14:28:41 (the eMMC in the beaglebone most definitely does not) Feb 04 14:29:02 and you've got industrial SLC SD cards Feb 04 14:29:03 that's just a cheap kingston, right? Feb 04 14:29:05 yah Feb 04 14:29:25 the sancloud "enhanced" has micron emmc Feb 04 14:30:08 hmm, so does a very old bbb Feb 04 14:30:08 BBB originally had micron eMMC, it was sloooooow... but then again they were ancient eMMC chips Feb 04 14:32:04 I've also had a device with some better eMMC where aforementioned OTP setting is actually permanently enabled, i.e. it doesn't cut reliability corners to squeeze out more speed Feb 04 14:37:04 hmmm..... where would I ask a BME680 question on IRC? (thinking aloud) Feb 04 14:47:12 the bosch sensor or something else? Feb 04 15:04:30 m Feb 04 15:09:24 m 2 u **** ENDING LOGGING AT Fri Feb 05 02:59:57 2021