The "I made this!" thread - Beginners achievements with pride. - Page 1
Forum section: electronics / beginners

author: paulca
author_rank: Super Contributor
timestamp: February 23, 2018, 03:13:52 pm
content: This thread is for beginners to post their achievements with pride.So you got an LED to blink for the first time, your wife thinks you're nuts and isn't interested. Then post it on here.Got your first op amp working? Don't want to make a new thread, post it here.Managed to figure out that tricky transistor circuit that's been bugging you for days? Post it here.Got your first Aduino sketch working, you're super happy, let us know below!So...What wasyourbig achievement today?Some rules:* Post one liners or guides with pictures, anything goes.* Feel free to discuss and advise but !!!KEEP IT POSITIVE!!!-Don't do that.You might want to try this instead.-You are doing wrong.A better way to achieve this would be...* Purely discouraging posts may be removed.* Be as trigger happy with the "Thanks" button as you can be.* Longer technical discussions, please start a new thread.* Remember the first time someone achieves a blinking LED or first Arduino sketch is still an achievement they can be proud of, remember when it was your first time?

author: paulca
author_rank: Super Contributor
timestamp: February 23, 2018, 03:17:58 pm
content: To kick off...I got an STM32 Arduino "Blue Pill" board to work. Blinky! Blinky! Neat little device. Also tested out PWM and verified it with my oscilloscope. PWM does not work on the built in LED pin though, it does bizarre stuff as apparently it's not a timer enabled port.

author: Cerebus
author_rank: Super Contributor
timestamp: February 23, 2018, 03:53:08 pm
content: Well done.For your reference, here's the "blue pill" board pinout with the PWM capable pins marked:

author: BrianHG
author_rank: Super Contributor
timestamp: February 23, 2018, 04:50:47 pm
content: Here I go:This was my first project using AdvancePCB/Schematic, which became Protel98/99se, and now is Altium, back in 1997.It is a sub-woofer enhancement processor I called Subwoff. It takes line level in, allows you to boost 25/20/15hz and below to ridiculous gains with an inaudible soft smooth rounding clip function allowing you to boost your speakers/amp subsonic rumble for movies. Yes, the filter is so perfectly tuned that no bass will be added to the voice or music, just the rumbling effect. It is stereo and allows you the feature to turn off the main audio so you can also use it as a active sub-sonic filter for a dedicated subwoffer instead. Documentation and full schematic is in the .pdfs.---------------------------------------------------------------------------------------------------------------------------------------------------I've included schematics & CAD CAM GERBER files with BOM. It is a 2 layer board under 10cm X 10cm allowing for cheap 5$ prototypes for anyone who wants to build it. The .pdf files have hi-res versions of the full schematic and PCB. It requires a 9vac or 12vac output wallwart to opperate,notDC. All the 10uf and 1uf caps should be non-polarized.---------------------------------------------------------------------------------------------------------------------------------------------------Full Gerbers/CAD cam files, bom and source files and forum topic for questions is located here:https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/msg1434525/#msg1434525

author: Peabody
author_rank: Super Contributor
timestamp: February 23, 2018, 05:32:41 pm
content: Here's one I just finished that any beginner could do. It started with building the DSO150 "Shell" kit oscilloscope, which is powered by an external 9VDC power supply (not included). You could use a 9V alkaline battery, but the scope draws 120 mA, so you would go through batteries pretty fast. So most buy a 9V wall wart to power the scope, and using that is not exactly convenient.But then I saw on the JYETech forum that guys were modding their scopes to be battery powered with a single cell LIPO such as one found in a phone or a quadcopter. The project requires a battery, a charging module, and a stepup boost converter to take the 3.7V LIPO output up to around 8.2V. It turns out there's room for all that inside the case. Everyone who does this does it a bit differently, but the pics below show where I put things, and how I connected them.The kit is about $21 at Banggood (a known source of genuine kits, and you have to be very careful about that because fakes are not supported), plus about $6 for a real scope probe (alligator clips come with the kit - not good). Then all the mod stuff totalled about $8.50, which is close to what a wall wart costs. And you need some resistors and wire, and a hot glue gun.Anyone considering doing this mod should install the kit's rotary encoder and the DPDT SW5 switch differently than described in the manual. Most of the work required for the mod was in undoing and redoing differently those two parts. Better to do them right in the first place. I'll post more on that if anyone is interested. Or just go to the JYETech forum, in the DSO150 group, and look for the long Lipo Mod thread.So in the end you get a battery-powered, single-channel, pretty slow oscilloscope, which it turns out is useful for checking all kinds of things, and for learning how to use a scope.

author: jerryk
author_rank: Regular Contributor
timestamp: February 23, 2018, 06:13:07 pm
content: I just took my first major leap from bread board to production of an interface to my mid 1980's security panel (main board and keypad interface) that allows remote security system monitoring via cell phone text plus control a lot of home automation stuff. The board itself is designed to have a 40 pin Raspberry Pi bolted to the bottom of the main board as the primary controller. It accepts 8 primary security system zone loops. All zones can be controlled individually and the key pad code can be set via cell phone or satellite communication device. Additionally it has 6 external relay inputs (for things like PIR motion sensors scattered around the property), 8 external relay outputs ( to open garage doors, turn on lights etc), 7 analog inputs ( house/freezer temp probes, ground water level, etc), 16 GPIO pin expander, and an onboard temp sensor. It's a single purpose board that I can't see the rest of the world having an interest in but is serves my goals quite well. I will be able to fire up my sauna while I'm out on a remote glacier skiing and have it nice and toasty so when I land back at home I can just hop in instead of waiting 45 minutes for it to heat up.

author: paulca
author_rank: Super Contributor
timestamp: February 23, 2018, 06:22:28 pm
content: "Harmful if swallowed",

author: BrianHG
author_rank: Super Contributor
timestamp: February 23, 2018, 06:28:14 pm
content: Quote from: paulca on February 23, 2018, 06:22:28 pmYup, nice too...

author: SirAlucard
author_rank: Regular Contributor
timestamp: February 23, 2018, 07:13:58 pm
content: So this didn't happen today, but I wanted to share my first adventure into chip writing, as for me it was a huge accomplishment.So story starts off like this. I had a project in mind that involved a teensy2.0 microcontroller. I was to use said microcontroller to interface with a Microsoft Sidewinder Force Feedback Joystick (the original one, not 2). This involved programming the MCU to interface with the Male DB15 connector of the Joystick. Well the programming part of things was already done by someone else on github and showed the wiring and parts needed to complete said project. I figured great! I'll just buy the parts I need an I'll be good to go. Well trying to save some money I went onto the fleabay and purchased everything I needed including a Teensy2.0++, I figured I'd get the ++ version so I'd have extra ports if I wanted to expand the project even further.Everything came in no problem, connected up the chinese Teensy and loaded some blinky examples that where available from the Teensy website. They Worked! I had been familiar with arduino coding and so since I was able to load up teensyduino I could program straight from there just to mess around with the Teensy a bit first. After playing around with the blinky program a few times changing the speed and what have you I noticed it stopped wanting to accept new code. No idea what happened I thought all was lost. I mean afterall it was a chinese knockoff so I figured I got hosed. Well several weeks have passed and I've done research over and over again to try to figure out how I can remedy my situation. The chip still worked as it would turn on and blink, it even showed up as being connected to the programmer. However no matter how many times I tried sending it code and it told me it completed successfully, the chip just kept blinking at the same rate even when I changed the speed. So I was at a loss of what had happened.So I decided that I'd try programming the chip directly. I researched how to do so and found out I could use my Arduino as an ISP to program the at90USB1286 I just needed a 16hz crystal connected to it and everything wired up correctly to do so. So I went through the process of getting what I needed. Because I didn't have any crystals on hand I decided to get some off fleabay because the ones on amazon were fairly expensive compared to the same kit on ebay. I didn't mind waiting the chinese shipping time. However weeks had passed since I ordered those crystals and I haven't seen them. I tried contacting the seller and got no response back. The item showed up as shipped however they never ended up showing up at my door. Eventually I had to put a dispute with ebay to get my money back. So I tried ordering elsewhere and finally got the package of crystals in.Two months have passed since I started trying to do this, so now I was finally able to connect everything! So I went and looked up how to use the Arduino as an ISP. As this was my first time attempting to do such a thing. Spent the time connecting my pins correctly connecting up the crystal and trying to re-program the teensy2pp clone. Well I had to program the bootloader, so I tried doing it. However it kept failing. I tried to set the correct fuses however the fuses never showed the correct thing. I kept getting error after error, trying different things over and over again. Looking up the diagram on how to connect everything and I just knew it had to be something stupid. But aha! I somehow missed that I needed to power the teensy with a 5v line, and I thought it was being powered, even tho no lights ever turned on. Rechecked my wiring and sure enough I had wires put in wrong. However there was another thing I discovered. I didn't need crystals, at all, because the teensy has one built in already on the pcb. DOPE!Connected everything back up and wrote in a command to check the current fuse settings. SUCCESS! It was reading the correct values! So I wrote in the command to change the fuses to the bootloader that I was going to load up to it. (HID Device) Success! Connected it up and it worked!Then the next part was figuring out the code. Originally it was meant for the Teensy2.0 not the ++ I've never really compiled something before so that was a whole journey in of itself. However it wasn't to bad. Figured out that everything was already set up in the code to allow for the ++ I just had to change a few lines of code and I was able to compile it no problem! I connected up the USB, used a different program to program the Teensy through HID, and as far as I knew it said it succeeded. Fantastic! I was ecstatic. Soldered up the DB15 connector to it correctly connected up the Joystick and I'll be damned the thing worked flawlessly! For something that no longer has any support or drivers for Windows 10, my force feedback joystick now worked perfectly with force feedback effects! I was so glad that I didn't waste my time or money on a teensy that I thought didn't work. For me this was a HUGE success as I had never programmed a chip directly before, never had to compile code before, and have done very little reverse engineering to figure out how things worked so I could get it working again.There is tons of this story that is missing, as I assure you a lot more happened than I wrote, including figuring out how to get the arduino as an ISP correctly, and seeing the LEDs have a heartbeat when correctly connected, which was cool for me to see alone, and a success. However I wanted to share my success story on making a usb interface for a Joystick that was over 20 years old, and to this day hasn't really been matched.

author: paulca
author_rank: Super Contributor
timestamp: February 23, 2018, 07:48:39 pm
content: Blinky .... Wot no Arduino!This might seemfairlypointless, but I wanted to do it anyway, as a step to putting an ATMega into a PCB it seemed sensible to create a test a prototype.But it expanded to... do I need the Arduino IDE or libraries at all?Arduino with no Arduino, not even a bootloader, fuses burnt with a breadboard. Bare metal AVR ATMega 328p. Aka "My UNO".To fellow beginners, this is what AVR programming might look like without the Arduino eco system!The ugly bits!Blinky code... slightly more complex than it needs to be, but I wanted to do "Blinky with no delay" to practice some interrupts. It's a bit ugly but functions.Code:#include <avr/io.h>#include <util/delay.h>#include <stdbool.h>#include <avr/interrupt.h>int on_time = 100;int off_time = 1000;bool led_on = false;int counter = 0;ISR(TIMER0_COMPA_vect){cli(); // No re-entrancycounter++;TCNT0 = 0; // Reset Timer counter valueif( led_on ) {if( counter >= on_time ) {led_on = false;PORTB &= ~(1 << PB1);counter = 0;}} else {if( counter >= off_time ) {led_on=true;PORTB |= (1 << PB1);counter = 0;}}sei();}int main (void){DDRB |= (1 << PB1); //Data Direction Register B: writing a 1 to the bit enables output// Start with LED offPORTB &= ~(1<<PB1);// Set the Timer Mode to CTCTCCR0A |= (1 << WGM01);// Set the value that you want to count toOCR0A = off_time;TIMSK0 |= (1 << OCIE0A); //Set the ISR COMPA vectsei(); //enable interruptsTCCR0B |= ((1 << CS01) | (1<<CS00));TCCR0B &= ~(1<< CS02);// What I like to do on a Sundaywhile(1) {_delay_ms(500);}}build.shCode:avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o blink.o blink.cavr-gcc -mmcu=atmega328p blink.o -o blinkavr-objcopy -O ihex -R .eeprom blink blink.hexdeploy.shCode:avrdude -C/etc/avrdude.conf -F -V -c usbasp -p ATMEGA328P -U flash:w:blink.hex

author: llkiwi2006
author_rank: Regular Contributor
timestamp: February 23, 2018, 07:52:10 pm
content: First time designing a PCB. Finally received it after some shipping mishaps. First thing I noticed: I got the silkscreen labels GND and 3V3 the wrong way round ...I hope permanent markers work on solder mask.

author: newbrain
author_rank: Super Contributor
timestamp: February 23, 2018, 08:15:20 pm
content: Quote from: paulca on February 23, 2018, 07:48:39 pmNeat idea. I always found the Arduino HW horribly overpriced. And the SW underwhelming (libraries and IDE).So I did the same as you (about one year ago).WRT yours, I've got headers and an user LED and button, plus Zener diodes and resistors for V-USB (with jumpers to free the pins).And my naughty bits are nicer than yours

author: paulca
author_rank: Super Contributor
timestamp: February 23, 2018, 10:42:21 pm
content: Quote from: newbrain on February 23, 2018, 08:15:20 pmLet's be fair the Arduino is not overpriced for what it is. It provides an amazing access point into digital electronics without which the digital 'gadget' space or maker space would probably not be anything like what it is today.It allows people to actually do constructive things without learning the datasheet version of the micro-controller. It makes it a tool and a powerful one. The odd thing is when you look at Arduino tutorials, they are all solving a problem and are practicals, in that sense they tell you "what" to do to achieve something. The datasheet only tells you what you 'can' do and nothing of how you solve any problem.That's worth a fiver!Our experiments have been to explore just how much the Arduino actually does to help people "get stuff working" which is really all they... we care about.

author: chris_leyson
author_rank: Super Contributor
timestamp: February 23, 2018, 11:54:45 pm
content: @paulca Totally agree, for what you get I think the price is very fair, I recently gave up trying to write code for a PIC24 and found I could get things done tens times faster with a UNO and the Arduino compiler. A PIC24 processor was a bit of overkill whereas an ATMega328 did the job nicely. I haven't used an Atmel processor in a long time but going through the datasheets I now prefer them over PICs. The other advantage of AVR over PIC is that I get them in much smaller QFN packages if I'm really stuck for space.There are a lot of very good Arduino tutorials and libraries and adding on your own hardware is easy. To be honest I've been far too sceptical about the Arduino platform for far too long and now that I've been playing with them I really like them.

author: KL27x
author_rank: Super Contributor
timestamp: February 24, 2018, 05:28:56 am
content: QuoteThat is a fun project, for sure.I did something similar with a pocket scope. If you examine the PCB for awhile, maybe you can figure out where/what are the other power rails. Surely, most of the power drawn in this scope is either 3.3V or 5V. You could potentially increase your battery life by using dedicated boost for the 9V rail, and a second circuit connected directly to the main rail. For instance, on my particular pocket scope the 5V rail was achieved with a linear regulator, so that extra 4V would be a complete waste. I removed the 7805 from the board, entirely.Also, you might examine the input protection on the 9V input. There may be a diode drop you could bypass.I have to admit I have no use for a pocket scope, though. I have a hard enough time using a real scope with real controls. These pocket scope have to come along a bit further for me to be able to do anything with them.

author: Jwillis
author_rank: Super Contributor
timestamp: February 24, 2018, 08:00:13 am
content: Not as advanced as some of you folks but I have a couple that I'm proud of.The first is an adjustable attenuator.That thing on the end is a 50 ohm terminator.It tests within 1 ohm so far but I haven't tested the decibel attenuation just yet.The other is a picture of a coil winder I modified to handle longer coils.Yes its a Tesla coil.Just a few nuts and a piece of ready rod and a little sheet steel .Still has some bugs but its doing what I need it to.

author: Peabody
author_rank: Super Contributor
timestamp: February 24, 2018, 03:03:16 pm
content: Quote from: KL27x on February 24, 2018, 05:28:56 amThere is a diode on the 9V input, which I assume is for reverse polarity protection. Then the resulting 8.3V goes to a 3.3V linear regulator which powers the entire digital board - the processor, the display, etc. So that's quite a drop. But the 8.3V is also converted to -8.3V with an ICL7660, and then those go through a 78L05 and 79L05 to produce regulated +/- 5V for the analog board opamps. I assume the design priority here was low cost and reasonable performance, not low power consumption.

author: BrianHG
author_rank: Super Contributor
timestamp: February 24, 2018, 10:37:39 pm
content: I completely re-done my free-for-all Subwoff sub-woofer project just now. PCBWay.com quotes 5$us for 10 PCBs + shipping with 2-3 day delivery.For anyone who want's to build their own, the full project page with cad files is here:https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/

author: Hextejas
author_rank: Frequent Contributor
timestamp: February 25, 2018, 08:42:06 pm
content: If I want to build this beast, which files do I send to the MFG ?

author: Howardlong
author_rank: Super Contributor
timestamp: February 25, 2018, 09:14:35 pm
content: Quote from: chris_leyson on February 23, 2018, 11:54:45 pmHorses for courses, I agree with your sentiments, Arduino is great to get stuff prototyped and when performance isn't key: that's the compromise, portable code, but not always the best performing. A big problem with PICs is that even within the same family there are significant differences between peripherals. I don't think the code generators help in anything but the short term, you still need to know how the peripherals work.I've lived PICs for >20 years so I find them more natural to use than Arduino, but I quite often go to Arduino if I'm looking for some code to drive a particular external device like an LCD screen or accelerometer for example, and port it. The code base from the Arduino community is enormous.Not sure which PIC24 you're using, but the majority are available in QFN.

author: Howardlong
author_rank: Super Contributor
timestamp: February 25, 2018, 09:19:52 pm
content: I'm not a beginner, but my analogue electronics, particularly on control systems, has always been crap for my entire career (several decades), so I consider myself a beginner in that respect.Today I managed to get the CC/CV working reliably (i.e., stable and not oscillating) on my poor man's 4 quadrant homebrew SMU.On the other side of the coin, it looks like I blew up my Maynuo M9711 electronic load, by inadvertently stuffing neg 15V into it when my SMU went into oscillation. Still, I guess I won't need it when I have my SMU completed.

author: Mr.B
author_rank: Unknown
timestamp: February 25, 2018, 09:30:17 pm
content: @Howardlong,Where do you purchase that proto board please?

author: Howardlong
author_rank: Super Contributor
timestamp: February 25, 2018, 09:43:45 pm
content: Quote from: Mr.B on February 25, 2018, 09:30:17 pmI get them from Mouser.http://www.busboard.com/http://www.busboard.com/surfacemountpcbsI use the ones with the solid copper ground plane on the underside, but not the plated through ones, I just link to ground with bits of wire through the pre-drilled holes as required. They are an excellent prototyping alternative for higher speed circuits, or designs with sensitive layouts such as this project.You’re never at a loss to find a ground to clip on your probe ground, anywhere free around the edge will work.This is the one in the pichttp://www.busboard.com/SP3-100x100-GI also use the 1.27mm pitch boards extensivelyhttp://www.busboard.com/SP3T-50x50-G

author: paulca
author_rank: Super Contributor
timestamp: February 26, 2018, 11:47:18 am
content: So I finished my first amplifier prototype board today.It's a fairly fancy little thing, a stereo Baxandall active gain pre-amp. Active gain in that the pot is on the outer feedback link.The downside is, it's current hungry and I'm not sure why. I need to get a good measure of it's current, but the opamps are fairly warm, around 40*C.

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 03:21:07 pm
content: I'm building my 20 year old project, the 'Subwoff'. I just ordered 10pcbs for 16$usd,includingshipping from 'JLCPCB.COM'.If I get between 5 and 8 people who want PCBs with all parts included for 40$usd plus shipping, I'll buy enough components from Digikey to build them all. For those who want to build these on their own, all the source files are here:https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/

author: Hextejas
author_rank: Frequent Contributor
timestamp: February 27, 2018, 04:39:42 pm
content: BrianHG, does Digikey have the Parts package under a specific name ?

author: jerryk
author_rank: Regular Contributor
timestamp: February 27, 2018, 08:46:59 pm
content: I'm suffering from severe excitement. My boards just came in from PCBWay.Jerry

author: paulca
author_rank: Super Contributor
timestamp: March 03, 2018, 11:00:30 pm
content: Not really a "I made it", but this is my first attempt at hot air soldering under a microscope. I think it's easier with just a magnify visor.

author: BrianHG
author_rank: Super Contributor
timestamp: March 07, 2018, 01:34:08 am
content: Quote from: Hextejas on February 27, 2018, 04:39:42 pmI just received the PCBs and getting in enough parts to assemble 2 of them. You might as well wait till I upload a before/after audio samples on the weekend here on the forum.If you take a look at my BOM files, the .cvs, tab delimited, scroll to the right and there are 2 different colums, with a 'Digikey' web link. But, this weekend, on my official project page, I'll add a 'Share-Shopping Cart' link/file from Digikey so you may order, add/remove parts as you like.https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/msg1434525/#msg1434525

author: paulca
author_rank: Super Contributor
timestamp: March 10, 2018, 04:19:14 pm
content: My first ever PCB! Second I have sent for manu, but it arrived first. The other one got stuck with customs.Have to wait on the bill to get it delivered.It runs a strip of WS2811 LEDs to make a colourful lamp for my 7 month daughter.KiCad 3D version:PCB Layout (there were a few revisions after this like putting the power the right way around!):Schematic:Few teething troubles:* ISP header has the power pins backwards (seems to be a theme)* ATTiny in SMD format seems to have slower fall times on the data switching, so I needed a 1k botch resistor pull down to force it to fall faster.But it works.This is the prototype running:

author: inventhouse
author_rank: Newbie
timestamp: March 10, 2018, 05:10:07 pm
content: Just installed one of the nifty DPS5005 power supply modules(*) driven with a 24V*1.8A into my "Hack-In-A-Box" toolbox, which also includes a RasPi 3, 7" LCD, 5V*7A power supply, extra charging ports, and a load of parts and tools(*)https://www.eevblog.com/2017/10/11/eevblog-1030-20-diy-bench-power-supply/

author: paulca
author_rank: Super Contributor
timestamp: March 10, 2018, 06:08:40 pm
content: Nice! I found the DPH5005 does a great job running on a LiPo battery. In your case a 24V 6 Series LiPo would work. They are quite small.

author: BrianHG
author_rank: Super Contributor
timestamp: March 13, 2018, 10:55:39 pm
content: Finally, built 2 Subwoff PCBs. Audio samples coming in 2 days. I'll be looking through Youtube movie previews & use one as an audio reference & provide 3 samples of original, Subwoff enhanced mixed audio and subsonic only at full blast.

author: BrianHG
author_rank: Super Contributor
timestamp: March 14, 2018, 12:30:12 am
content: Holy S--t, this sounds insane with modern recordings which have VLF all over them. I'm adjusting 1 gain resistor value, otherwise, it all rumble and nothing else...Cad and now BOM updated here:https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/Preparing audio samples this Thursday... For some of you with good 20Hz sound cards/cd players/amps & OK speakers which go below 40hz, get ready to rumble.

author: paulca
author_rank: Super Contributor
timestamp: March 14, 2018, 08:19:07 am
content: Not sure if it helps or gives you ideas, but the sub woofer I have for my car (with built in amp) exposes it's amp parameters.Freq - the peak point of the gain frequency.Q - The width of the frequency which is gained.Gain - How much gain is applied.Level - The amp output level.It's important when you put the woofer into an enclosed space that you try and avoid gaining too much frequencies that cause standing waves or resonance in the car body which just rattles stuff. I found with everything in the middle mine sounded fine until I put the back seat up, then it sounded boxy and boomy. So I dropped the frequency and tightened it little to avoid boosting the higher bass frequencies, this fixed most of that problems... just my fillings that rattled then.Also, enjoy this:

author: BrianHG
author_rank: Super Contributor
timestamp: March 14, 2018, 07:40:02 pm
content: Quote from: paulca on March 14, 2018, 08:19:07 amIn the 25hz setting on my Subwoff booster, that's nuts. I don't think my neighbors like me anymore. But, in the 20hz and 15hz settings, that music doesn't do much except for the odd fewest lowest notes in the 20hz setting. In fact you know it's bass since you can hear it...That music is mostly bass, not subsonic. Even the cheapest film/movie, or good TV show has tremendous effects in the 20hz setting. Only the very special scenes are in such Hollywood action blockbuster makes it through the 15hz setting.Remember, a lot of subwoofers start below 100hz, or 50hz, or 40hz. I'm talking about the inaudible stuff below 25hz.

author: lordvader88
author_rank: Frequent Contributor
timestamp: March 15, 2018, 05:03:39 am
content: Cut up and re-used a TV remote control PCB to make a little series pass regulator with LM358 and LM336 Vref , for 3V to power a cheap but functional Vici VC99 DMM. Its using off a 12V transformer. PCB fits neatly in the battery case. 1/2 deadbug, 1/2 through-hole

author: jerryk
author_rank: Regular Contributor
timestamp: March 15, 2018, 05:08:05 pm
content: My security upgrade is now in its final resting place next to the old system I had installed over thirty years ago. The enclosure was an obstacle by itself but worked out in the end.I did make a few mistakes in the final board run. The main power plane connecting all of the 220 resistors to the optocouplers had a tiny gap that mean I got to solder bridge all the resistors to that plane. I created a couple of unconnected islands that had to have belated vias installed. I omitted a control wire from the pi to the adc, hence the jumper wire around the pi pins. With a few more ugly solder bridges here and there it actually works as planned. The biggest goof was mounting the pi mirror image to my intentions. It was supposed to go directly under the board and not staggered. I spend so many hours checking so many things and missed that one! Regardless of the stumbles, it's functionality is beyond my expectations. The best part is remote control of the keypad. Unravelling the serial code used to control it took a while but the ease of making changes to the panel via a computer instead of the dreaded keypad is worth the effort.Thanks to all of you that helped me in this project.Jerry

author: BrianHG
author_rank: Super Contributor
timestamp: March 16, 2018, 04:02:13 am
content: The Subwoff 'Lost In Space 2018 trailer' audio demo is here:https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/msg1453438/#msg1453438

author: yashrk
author_rank: Frequent Contributor
timestamp: March 16, 2018, 05:46:59 am
content: Quote from: jerryk on February 27, 2018, 08:46:59 pmNice rounded corners

author: BrianHG
author_rank: Super Contributor
timestamp: March 16, 2018, 06:18:34 am
content: Quote from: jerryk on March 15, 2018, 05:08:05 pmI still love that 'Harmful if swallowed...' comment on your silkscreen.

author: IsabellaMiller1950
author_rank: Newbie
timestamp: March 16, 2018, 10:29:46 am
content: Quote from: BrianHG on March 13, 2018, 10:55:39 pmCongrats! Does it meet your expectations while using?

author: BrianHG
author_rank: Super Contributor
timestamp: March 16, 2018, 09:42:17 pm
content: Quote from: IsabellaMiller1950 on March 16, 2018, 10:29:46 amIt's great for older material before 2005, gives it a modern feeling. For newer stuff, it's insane! My neighbors don't like me anymore..mp3 sample demo here:https://www.eevblog.com/forum/projects/free-subwoofer-audio-processor-project-for-forum-members/msg1453438/#msg1453438

author: paulca
author_rank: Super Contributor
timestamp: March 17, 2018, 11:37:59 am
content: It lives!Binary clock. First PCB I ever designed. Though it arrived after my second PCB.ATMega328P, DS1302 RTC w/ 3.6V NiMH battery, TLC59282 LED Driver, Adafruit 128x64 oLED.The most surprising thing is... I have found zero errors so far. It worked out of the bag. Quite surprised.In the photo it's running off an 18650 laptop cell, I have TP4056 board to allow charging. Just wondering about a case now.

author: paulca
author_rank: Super Contributor
timestamp: March 29, 2018, 06:51:23 pm
content: So I made a sound card. A USB one. Based on the TI PCM2904 USB DAC. Works a treat, both output and input. No drivers needed, appears as "USB Audio Codec" in windows and Linux. Will drive a pair of headphones at nanny state level, but put it into a decent headphone amp and you will find it is not short of gain.All SMD with the exception of the white power LED. Air soldered with an 898 clone. All components ordered from RS Components. It wasn't exactly cheap though. BOM and boards for 2 + left overs was about £100.Designed in KiCad with lots of help around getting the output filter designed from the kind folks on here. Ended up using a butterworth filter from a TI Application/Design note/Demo board.Full sources for KiCad is available here:https://gitlab.com/paulcam/PCM2904_DACBoard manufactured by AllPCB for $22 including shipping which only took 6 days end to end. I ordered 5, they sent 10. The boards would have been $15 but I wanted blue solder mask which added $7.(On the topic of gain, if you want to drive headphones (at all) or an headphone with a bit of kick, swap R8 and R9 for 3.9K instead of 12K.)It's mind boggling to think I went from asking dumb questions about Ohm's law in October to making a full USB sound card device this week!Oh and.. jerryk, you have started a trend with your "Harmful if swallowed.""For external use only!"

author: davethecipo
author_rank: Newbie
timestamp: July 07, 2018, 05:29:16 pm
content: Hi everyone!I followed the "Getting to Blinky" tutorial from Chris Gammell to familiarize myself with Kicad. This is my first PCB. I used through holes components and the bipolar version of the 555, which I already had, instead of the CMOS version. 9V battery for the power. First of all, I want to thank Chris for the tutorial.Now, coming to the beginner mistakes I made, this is what I found:1. I flipped the + and - signs on the silkscreen...doh!2. Pin 5 (Control Voltage) shouldn't be connected to Ground, therefore I had to lift the leg of the 555. The manual suggests a 0.01 uF cap.3. I got the wrong footprint for the 555...next time I'll double check4. I got the wrong polarity for the LED...double doh!!The main lesson for me was to RTFM and double check the footprints. Anyways at the end of the day I'm very happy!