Feel free to disagree. Welcome to feedback.

I know it is very subtle and hard to tell if there’s a difference but it’s been a while since I tried changing it. I think I once read that it changes a resistor value but I can’t remember what it is supposed to do. maybe some buzzwords like making it more mellow or less harsh which might translate to changing the depth of the sweep and maybe we need younger ears because maybe the change is only in the upper frequencies. an oscilloscope comparison might be interesting.

i’ll have to look for that and check it out. I just recently watched him tear apart that Apple charger.

Hi Dustin, happy new year.

@@TheEmbeddedHobbyist Hi Thanks! You too of course!

it sounds to me like the waveform of the low frequency oscillator is not the same because the sweep seems different. I’m curious about studying the schematic and then tracing signals to see what it’s doing at some point.

when I need to replace those conductive pads I glue on one from a kit that is close to the same size Button pad repair kit: Amazon.ca: amzn.to/3VRAIYi Amazon US and others: amzn.to/4aAK6ni

I was using whatever the default wire library would do with the Adafruit ADC library and I think it was just single readings, I pulled up a sketch from years ago and just added extra channels to make sure I could get it going but it also looks like the library for it has changed over the versions, had to fight off compile errors. So I need to look into it all again and get up to date and try some more in-depth testing now that I know it’s a viable thing

@@gadgetsideload one of the reasons i stopped using the Arduino IDE. Libraries should be backwards compatible, if you change the methods you should leave the old one in place. but anybody can post a library and no one cares how well they are written. Plus i find they only contain the easy bits of the datasheet or the the one bit the writer wanted to use. Far easer to write your own, plus your learn a lot more about the chip in the process.

at some point along the way I started noting in the comments at the top of sketches, the version number of every library and every board file that I used at the time I was working on the project. and then eventually I also started making note of the Arduino IDE version because even that caused problems. there was something going on with ESP board files I can’t remember if it was affecting ESP 8266 or ESP 32 but certain things would not work unless I rolled back to version one something. I recall some problems with SD card libraries, I don’t know if that’s the same problem.

I think I first used these five years ago and back then I remember reading something about how even though they are called 16 bit there might only be 15 practical bits but I forget why. I have to dig into it all again. One thing I do need to look more into, I was running these at 5 V but later when I tried at 3.3 I was getting weird readings like suddenly whatever inputs had ground versus 3.3 V, I was seeing those readings show up on different channels in the serial monitor but they were working fine at 5 V so I don’t know if it’s because I was using the esp that was acting strange or a different library version, some debunking to do.

@@gadgetsideload I've been frustrated for years, trying to make an inexpensive measuring tool for multiple battery voltages. Dedicated chips seem to work better than MCUs ... but still, hard to get real stable, fast 3-digit accuracy.

good luck in measuring the characteristic of a 16bit ADC, been there and done that as part of design verification of an asic which was being designed for us. Takes a lot of expensive equipment and way too much time to want to do it for fun. I had to re-run after every change made don't know how many months (close to a year) I must have spent just checking the ADC. 😞

@@GnuReligion how fast to you need them to be, I've found batteries to be quite slow to do things. i'd go for dedicated chips every time.

I think it is some kind of hard rubber and that’s why it sort of melts over long periods of time and becomes goo but if it was just plastic it would probably become brittle and fracture as solid pieces of plastic

Are you in a 110V place with a tip on 220Volt ? You probably need to switch out the small heater-unit inside the iron. Just my guess...

I can’t remember exactly how things were hooked up but glancing at what I see on the table, that other breadboard does look like it has the 555 with a variable duty cycle possibly as an audio test source. The final audio output was that orange amplifier and I had a clip on microphone laying on the table to pick up the audio and record it on a zoom H1 which is sitting beside the orange amplifier. and the audio going to that orange amplifier is from the green cable with the black stripe and that’s going over to the breadboard with the echo circuit so it must be coming out of the actual Eco circuit directly. I can’t seem to follow the cables for the other circuit board to the left of the battery pack it looks like the 555 audio is going on the green cable into that White circuit board and then there’s two outputs I think it’s a splitter to buffer that, but it looks like one of those cables doesn’t go anywhere and the other one is probably going to that black mixer so maybe I was using the white board as a buffer or maybe I was trying something else and it didn’t work so the board just got left there because it wasn’t hurting anything. so overall it looks like maybe the 555 oscillator is going into the black mixer and so is the talking microphone and then the output of the mixer somehow gets connected to the input of the echo circuit and then it goes to the orange amplifier and gets recorded by a clip on microphone.

@gadgetsideload wow thanks for your reply. I'm trying to hook my output to a scarlett solo interface as we speak. Wish me luck!

Works a treat ☺️

Well, I think it is running on mains (so 220 Volt here). So both for the iron as for the hot-air part. I just don't know how it is calculating the temperature since there is no visible thermistor or such in the handle. So I guess it is somehow calculating the resistance in the heating-element and by a lookup-table or formula in the processor switching the heater on/of very fast.

Goertzel algorithm libraries might be able to decode the frequencies in the audio but I’ve never tried it and some people have found it to be inconsistent. Maybe if the chip is doing too many other things it could be even less reliable to the point where you need a separate chip anyway. www.hackster.io/MM_Shoaib/dtmf-decoder-using-only-arduino-872502

@@gadgetsideload I have successfully detected DTMF with Goertzel. However, for Call Progress, I still depend on CMX673, I would be very grateful if you could create a library to detect Call Progress Tone, especially to detect Bussy Tone, and Hello Voice :-)

@@gadgetsideload kzbin.info/www/bejne/pqqZpoewj5Vqn6Msi=AyFb04gPjdhGzUfz

if the main voltage supply rail is being dragged down dramatically when something is connected it sounds like a short circuit or bad component drawing excessive current.

If someone can tell if the RX dropping that low is to be expected while not transmitting, please let me know.

is that while applying 3.3 V to the Vin pin? and is that with a CH 340 chip? I think the module vin pin is intended to take higher than 3.3 V so the onboard regulator can bring it down to 3.3 but I’m not sure if the regulator on these modules just passes through 3.3 in to out without a drop out. having 2.6 on the Rx pin is definitely not normal and it’s around the bottom threshold for detecting logic high which I think is 2.65 V when running at 3.3 V so it definitely needs to be run differently to get that back to 3.3 V.

I think I started this channel 3 years ago and originally it was just a parking spot for extra long schematic or software discussion that would not really fit in a regular video but now I’m not even sure if I should actually put proper content of certain project categories on here as well so I’m letting it evolve on its own.

The project is shared on PCBway www.pcbway.com/project/shareproject/Phone_Line_Simulator_POTS_Land_Line_1d34078f.html The one component they seem to have trouble sourcing is the 600 ohm transformer because I just buy them on eBay or AliExpress so when people buy the assembled project there, I think they have to just tell them don’t put the transformer and people solder one in themselves.

@@gadgetsideload Thanks I submitted an order for 5 units to your link. It is being reviewed for assembly now. I made note of omitting the 600 ohm transformer if it was not stocked. I will let you know how it goes.

I am also currently working on another accessory board where if it works, several of these can be plugged into it so that calls can be made between multiple boards at the same time or even party line multiple notes together. if that goes well I could be making a video within the next two months for it.