Julian's Postbag #49: MP3 Module, LTC4150, LCD 18650 Box

Bags of goodness from the Far East...
Want more Postbag videos? I've set up a Patreon page: www.patreon.com/julian256
TF card U disk MP3 Format decoder board amplifier decoding audio Player module www.ebay.com/it...
www.icstation.c...
www.linear.com/...
cds.linear.com/...
Universal 2600mAh USB Power Bank Case Kit 18650 Battery Phone Charger DIY Box www.ebay.com/it...
www.banggood.co...
Hip-Hop track: Blue Smile by Gunnar Olsen
www.youtube.co... (then search by title)
Note: Some items were supplied at zero cost.

[@muh1h1]

i love your "i don't need it, but it was so cheap, so i had to buy it"-purchases :D

[@mankee2211]

+muh1h1 and the "I forgot what I bought" purchases!

[@Strawberrymaker]

+John Ridley have the same feeling. going on aliexpress. "Oh thats just 3$, thats cheap" - 60$ laater

[@JaqiesGadgets]

+John Ridley I bought a bunch from alice the last few months too... they make it worse too by the more you add the more you save on shipping!

[@Strawberrymaker]

John Ridley "Its so cheap, im going to add 100 of them" - me everytime when i buy smd parts xD No i have a collection of ~30 * 100 smd resistors and capacitors, where i needed every set for maybe one project xD

[@MrHermansWorld]

the MP3 decoder board uses the GPD2856C boombox chip.

[@christmasdreams1]

You know what I love about your videos ? They are so real life - un-doctored comments, wandering aimlessly, yet intelligently, as you try to figure out the tangled mess that often passes as Chinese technology! I am happy, and extremely proud, to say I am exactly the same - my loved ones know never to answer a question that I have muttered to myself, or chide myself for silly mistakes (such as not checking polarity - hahaha! I loved that one!). My Chemistry professor always said, if you can find wonder in even the smallest things, then you are truly blessed! You my man are blessed! Thanks for your channel.

[@jlucasound]

Big thumbs up for you, Derrick!! Julian is one of my all life heroes.

[@kyoudaiken]

I would request a refund for the LTC4150 module because the supplied connector is misleading!

[@vgamesx1]

+BloodySword Yes, I possibly would have fried it too.. I can see how it's easy to screw up and simply plug a battery in thinking it'll be fine.

[@roidroid]

re: MP3 player. it's weird to see something that has both a battery and USB power options, but no power regulator anywhere on the board. So i guess the chip itself will happily run at "whatever" voltage, very chill.

[@rich1051414]

I am sure the timer is for elapsed charge and discharge time. You can use that info to determine how much capacity your cell has.

[@JerryEricsson]

I am a sort of MP3 and MP4 freak. I have lots of MP3 players as well as a few mp4 units - that said, I just had to get one of those little gems you showed here. Being a bit more in a hurry then a spendthrift, I ordered one from here in the US for $4.30 and it came in today. I have been playing around with it, using an 8 gig tf card and a small lipo battery. My battery was nearly dead on hookup so I plugged her in, and it charged with no problems, no excessive heat problems here but I see that I shall need to put a switch on the unit as that little red LED stays on even when not playing. It could use a few more LEDs if a fellow could just figure out where to hook them up but since there is no diagram available, hell I can't even find a number on mine to look for one. Like yours there are no markings on the chips, mine looks like a sander hit the tops but I could be wrong. With a set of headphones the sound quality is better then my little iPod and that says a lot (using the same headphones.) I have some tiny amplifiers and little speakers, I may hook them all up and see if I can make a small mp3 audio player for our motor home. Perhaps with a real wood case if I can get out to my woodshop before the snow flies here in South Dakota.

[@JulianIlett]

+Jerry Ericsson All that fun for $2!

[@JerryEricsson]

+Julian Ilett Just returned from our winter quarters in Arizona, didn't take this little player along, but we are on our second day home, and already it is on the arm of my recliner. Love playing with it.

[@drumid1881]

5:00 - thumbs up if you had the shit scared out of you. I had the volume up and my headphones on.

[@JaqiesGadgets]

MP3 player jack looks busted! TF=TransFlash, compatible with micro SD.

[@EdwinNoorlander]

thanks Julian, I like the 'multi postbag' video's to. And I can't wait until the next video. I really like your logic steps and how you talk the way along the video. 👍🏻👍🏻👍🏻 bigs thumbs up and cheers. 🍻

[@GorkemYildirim]

This speaker is 8 ohm and only 0.2W. They advice 4 ohm speaker. Then it will give 3W max at 5V input.

[@ReflexionesCristianas0.5]

hey what's up bro? i just got two of the tf card and I been looking for the way to adapt a remote control sensor receiver because I bought a emote control IR remote control , so like I said i been looking for the way to adapt a remote control but It been impossible to find it? I wondering if you can help with this little project. thanks I will appreciate your help.

[@martinj9268]

I can't believe everyone is shitting on the mp3 board. I got one of those months ago to stop killing my phone battery listening to music in the car, and it works great! A lightly modified $5 below power bank, one of those boards and a $10 micro SD card and I have an MP3 player that only needs to be charged every couple weeks for $18!

[@helpmode]

Is it possible to use one of those cheap MP3 modules as an function generator if you would have different signals as MP3 files?

[@HouseOfHacks]

That LTC4150 breakout board looks like it has some holes next to the sense resistor. Wonder if you could put a different resistor in it for monitoring higher currents.

[@louisesearby7522]

.The chip is a GPD2856 , on the MP3 player lol The chip on its own is £4.18 BUT 5 CMP3 PLAYERS COST £6.13 LOL

[@llhand]

Powerbank. Is the timer showing elapsed discharge time?

[@petemoss1938]

On the LTC 4150 the silkscreen on the board matches the + and - of the 'external' power supply pads but NOT the socket connections -even more misleading! (Is this why the damn thing is so cheap?)

[@ytuploader]

I'd hazard a guess that the controller IC on the MP3 player is a GPD2846 or one of its variants. "Datasheet" here: pdf.icpdf.com/uploadpdf/SUNTAN/GPD2846_datasheet_1065480/173079/GPD2846_datasheet.pdf There are a number of modules based on this IC dotted around eBay, with the part number shown in the listing and at times an unobscured chip.

[@Luke-san]

For $1.81 you can't even buy bread nowadays. This is just getting a bit crazy now if you think that it has to come from the other side of the world. Well ordered it. Will use it to play music when the sun is out with a panel. Time to search for stuff which we are supposed to throw away.

[@iamamo2min595]

Julian I've created a 4 batteries in parallel and I used similar to this charger type only mine has red light for charging and blue when discharging, pay attention that the usb out voltage is boosted to 5.7v, so its useless for one battery cell, it wont even last for 30 min to charge an old Nokia phone, so I've increased the amp in my setup which now takes ages to charge lol, I use it mainly to power my led light when the electricity goes off and last for about 4 hours.

[@deslomeslager]

I do prefer one item per upload. I now have to filter all comments looking just for the ones I am interested in, and they all are criss-crossed. So please do one at a time?

[@suretecnik]

Anyhow can we get the input audio connection in this circuit, as it don't support Bluetooth

[@artemisXsidecross]

Thank you, I enjoy learning by the method you use of not trying to over explain but to communicate as if all knew as much as yourself. I find this kind of learning to be as effective if not more effective than the more logical method of step building that is used in most methods of teaching or education.

[@JulianIlett]

+artemis sidecross What an interesting comment - thank you.

[@thelitecommando]

It annoys the crap out of me that some companies use "TF" and some use "MicroSD"...

[@danielhorne6042]

theres only 2 chips on that amplifier the long chip is a - GPD2856C-009A MQPA285.1 1644 . the smaller chip is a : 80002B WX0129 the amplifier & i checked where the cell + track leads to it gose straight to the amplifier so its directly connected to the usb input

[@ConanRider]

Does the MP3 module remember its place or does it start from the beginning of the disk when you remove power?

[@JulianIlett]

+TheConanRider By answering this question, I'm probably spoiling the fun for anyone thinking of buying this module! It seems to remember the track, but not the position within the track, or the volume level.

[@MarkMarooth]

Durn it, another visit to BangGood courtesy of you Julian. Bought 6 power banks, one in each colour will make excellent stocking fillers for Crimbo. Well, I have recently acquired over 400 18650 cells from old Lappy batteries for my mega "off grid" workshop battery so a couple of the really gud'uns Will not be missed. New to this KZbin thingy but love the channel and have been inspired by you, Big Clive, Mike and Dave in oz to have a go myself. Cheers!

[@JulianIlett]

+Mark Marooth They sound like excellent gifts. Although a relative recently asked for a single-cell powerbank for a foreign trip and I insisted on the metal cased one. Just felt a little more comfortable having the LiPo encased in aluminium rather than plastic.

[@MarkMarooth]

+Julian Ilett I'll bear that in mind Julian, thanks.

[@XFolf]

I like the multi-item postbags myself :)

[@tengelgeer]

You can test if the MP3 board has a charger build in (I don't think so). Just connect the USB and measure the voltage on the BAT- and BAT+. I think it will just read 5V ;) Also, I don't think it has a step up. I think the USB-stick was in the end (after the cell was charged cruelly) happy to run of the battery voltage. And V- en V+ need a long press. Tried the long press the button for mode? Th Gvf of the LTC board is just in the specs. And yes it's the 32,55Kz/V but it can have some deviation. For the power bank, I think it just counts the time from going on. And short pressing the button will re-turn it on thus resetting the timer. And I think the battery symbol is to show it's providing power. Maybe even indicate the level of current?

[@ozzelot3349]

Hiya, I just tested the MP3 board and it indeed outputs 5V on battery terminals. And for the Udisk I measured 4.07V while on battery (equal to my battery voltage). So indeed, this thing doesn't have a charger nor a step-up. Mode button (long press of P/P) is supposedly for switching between Udisk/TF card (haven't tried).

[@Eratas1]

I think that MP3 module is so cheap because those mini clip MP3 players cost 1$ including battery!

[@SproutyPottedPlant]

I knew you would figure out what a TF card was a little way into the video and I was right 😁 love the power bank, need a NiMH edition!!

[@llertas]

Multi is better :) thank you

[@dafuqucare2527]

cool video Julian, thanx. I got the exact power bank from Banggood but in black color. And I use it to recharge my mobile but mine also came with a short microUSB white cable. That timer is shows charge and discharge time and only goes up to 2:00 AND the button has few uses. It switches views between timer and charge when pressed ALSO if pressed and held it will turn it on/off. The USB male port is used for powering devices while the microUSB port is used for charging the power bank. I also use it with Xiaomi(Mi) USB fan and led: store.mi.com/my/item/3152500008 cheers.

[@regbateup1184]

Hi Julian, Can do a video with a new (not-fried) LTC4150. I'm interested to see how different this to the MAX17043 on a ESP8266

[@Alex1zi]

Hello Julian cann't Please make the video player module is connected to the speaker 3-5W

[@jlucasound]

We Love Alice!! Alice1101983. I am not affiliated with Alice in any way, other than I am a customer in the USA.

[@AerikForager]

I have a couple of the little power bank boxes, I got them from Banggood. They are really cheap but useful, the clock tells you how long it has either been charging/discharging. The little button can get lost inside the screen during shipping and getting it properly placed in the hole is a pain, but possible. The clips on the back cover are meant to keep it permanently closed, but with thin tools can be opened without breaking. P.S. 30 mins of fun or so. ;p

[@leberkassemmel]

I go the same (or very similar) board, and the 8-pin chip was a 8002 amplifier. Yes, they did a very poor job on mine with removing the part numbers.

[@martinstuart]

Hi Julian, Quick question, if you don't mind: Do you think one could remove those volume buttons and wire to an external potentiometer?

[@tartrazine]

They are not pots on the board but momentary contact vol up/down and select buttons. You could extend those to a front panel though.

[@Mittin08]

+Tartrazine thanks!

[@zaprodk]

Oh, those solder joints on that USB-connector seems pretty starved of solder :D

[@StealthAngel667]

Not only am I baited into building a completely unnecessary MP3 player, I now know you can count coulombs. So much random information in one video.

The power bank, is it always on? So if you connect something drawing low amp (

[@allisonbarrios203]

I will like to see a teardown of your multimeter I have that same single 18650 power bank and carry it in my purse and its really useful!

[@MrHermansWorld]

And yes, you will find some good pictures with readable chipnumber at aliexpress dot com ...

[@deaultusername]

MP3 player is a GPD2856c chip

[@haydenc2742]

tp4056 to charge a small lipo battery, the 3watt amp is the bigger chip...neat little module

[@ELECTROHAXZ]

Then how does it play the MP3 files?? You have to have a chip for that too

[@playdav485]

hi i was going to purchase 1 of those power banks after seeing this video. can you do a video checking the standby power or idle power compared to other power banks?

[@ericsensico6313]

Does.it have a built in charger module?

[@drkastenbrot]

Tf cards and u disks are just micro sd cards and usb sticks.

[@liamharrison3]

you missed a charger doctor opportunity on the mp3 module to see what it was putting out for the "u disk"

[@JulianIlett]

+Liam Harrison Dammit, I did miss that. There's no step-up circuit - the USB stick was working at 3.7V

[@liamharrison3]

I love weird cheap electronics design decisions. They go to all that trouble to accommodate you with an amplifier, two types of storage and a repeat button but miss the fundamentals like a battery charger and making sure there is 5v on the USB. Or maybe my expectations are all wrong. Who knows!

[@p1nesap]

PG Tips or Twinings?

[@lmaoroflcopter]

tf= transflash. aka microsd

[@MrMistery101]

Yay! Finally something that is mildly intuitive for a physics major.

[@planespeaking]

Great video as always. I really enjoy them and they're amusing as well as informative. Thanks

[@InterRubke]

And now a way to control the MP3 module from an arduino and we have a perfect audio shield. I wish there was a datasheet.

[@AceadamUK]

you scared the shit outta me @5:08

[@drummerdoingstuff5020]

Your “ hip hop” is adorable

[@kamleshkumarsharma5858]

Does it support Bluetooth

[@danielhorne6042]

unless u have a lipo cell with built in protection

[@krisztianszirtes5414]

TF is the "T-Flash" card which was used in a few mp3s I had and there are sd adapters for it. It's uncommon and useless in that form pretty much :D

[@thelitecommando]

+Krisztián Szirtes uncommon? almost all android phones have a TF (compatible) card slot...

[@krisztianszirtes5414]

[EDITED] Yes, I messed up. I was thinking about a rather large TF card that was used in one of those said mp3s. It is indeed the SD card (means transflash) and is very common.

[@iceberg789]

more fancy devices, it's hobbyists paradise these days !

[@fuzzybobbles]

if you remove the usb and the speaker connector from the mp3 decoder board you could hack it to make the ultimate musical birthday/christmas card.

[@JulianIlett]

+fuzzybobbles Yeah, I'm thinking of making one for the wife. Four hours of me talking about electronics ;)

[@fuzzybobbles]

+Julian Ilett It would make a good youtube projectvideo as well. Then I can make one for my girlfriend.

[@johnrana9698]

How to reset it?

[@Edu_RJR]

ahh :( wanted to see that "coulomb" counter in action

[@achtzehn4630]

can we add bluetooth module to the mp3 module directly?

[@abco-nq6md]

3W speakerOutput is mono and not stereo? thank you

[@johndii2194]

I do like the MP3 Module. Is the audio out jack stereo?

[@Sopaco23]

Dear Julian, just connect vcc it starts playing the first track or you must press play? Thank you so much.

[@martinj9268]

Sopaco23 mine seems to work usually by just applying power, though sometimes you have to press/hold the "P/P/Mode" button. Granted I only ever use it with files on the root directory of an SD card. never tried a USB drive or sorting through folders and such.

[@realtrickybilly]

Thank you. Subscribed.

[@jesuishalil]

volume warning would have been nice, scared me xD

[@mirasshayken8129]

Есть русские?

[@mankee2211]

why didn't you check the voltage on the battery terminals on the MP3 player for 5V, when the power bank was connected?

[@JulianIlett]

+Dave P Not sure. But it has taught me that pumping 5V directly into a 3.7V lithium cell doesn't make it immediately explode. Fortunately :)

[@mankee2211]

+Julian Ilett I meant after you noticed it's getting hot. You only said you're not sure, so I was yelling at the screen ;) but thanks for sharing, I like those mailbag videos in general - they are inspiring new projects and present stuff one might havent seen yet.

[@JulianIlett]

+Dave P Just checked it now - the micro USB socket and the LiPo connection points are in parallel - eek :/ Thanks for the thanks.

[@jusb1066]

+Dave P i guess its too much to hope for right now, maybe they will revise the design and add a li-ion charger module, that would increase the usefullness. I quite like this module, i have a hankering to make my own speaker housing/mp3 player one day, maybe find one with a lcd display for tracks though

[@JulianIlett]

+jusb1066 You could cut a couple of PCB tracks and add in a TP4056 board. I'll look out for one with a LCD - might have to spend £2 on that though!

[@JasonPrice1]

Julian, have you ever checked the cut in/out voltages on these "add your own batteries" power banks? I bothered to check it on one of my Aili 4 cell units and the high/low is 4.3v/3.1v. So charging a bit longer than maybe it should and certainly not discharging down into the 2.5v range that a Li-Ion can handle. I have one of those wee little PCBs that will charge and discharge cutoff an 18650 and it does do it proper at 4.2/2.5. Thanks in advance!

[@electrodacus]

+Jason Price 2.5V is for sure to low and improper for LiCoO2 cells. Even 3.1V is a bit low but for sure much better than 2.5V. 3.3 to 3.4V will be the proper cut off voltage on most LiCoO2 cells used with relatively low discharge rates (below 0.5C)

[@JasonPrice1]

***** These are Li-Ion not LiCoO2. All of the spec sheets I have ever seen for Li-Ion are for an operating range between 2.5 and 4.2 volts. Some are spec'ed higher but they are purpose build for certain uses such as in power tools.

[@JasonPrice1]

***** Example: industrial.panasonic.com/lecs/www-data/pdf2/ACA4000/ACA4000CE240.pdf These cells are rated to 2.5v.

[@electrodacus]

+Jason Price Li-ion is a generic therm (all Lithium batteries are Li-ion). The most common battery in the world is LiCoO2 used in most laptops, cellphone and other portable electronic devices. All this devices have low charge discharge rates so they last at least a few hours so that a typical device last worst case 2 to 3h and average discharge rate then is around 0.3C worst case. Most other device like cellphones have much smaller average discharge rates well below 0.1C. This is important become the discharge rate dictates the low cut of voltage. Yes spec will show tests done down to 2.5V like the spec you linked (that is a test not recommended operation). Look in there more carefully to the discharge characteristics graphs and see how at around 3.4V there is not much if anything left in the battery going below that point will not give you much extra energy at the cost of battery degradation. In the last graph at 0.2C discharge rate you can use 2800mA if you cut the discharge at 3.2V and 2900mA if you cut that at 2.5V So you are willing to sacrifice the battery life to gain at most 2 to 3% more energy out of the battery by going from 3.2V to 2.5V cut off voltage?

[@JasonPrice1]

***** So is your answer to my original question that it is better to have the higher cutoff voltage to maintain lifetime of the cell? If so, I already knew that. I was trying to see if all of the DIY power banks were 3v and higher for the lower end cutoff and Julian has the most I have seen of any KZbinr and wanted to know if this was a common trait in all of the units he has worked with.

[@NoxMarcus]

I think the connector on the LTC breakout is in parallel with the resistor. I would guess the board is intended to be connected in series with the load circuit, the same way you connect a multimeter for current sensing. Also I'm pretty sure it's polarity independent on the sense port. But 3.7V on a +-50mV port might have cooked something. Though the internal circuit shows 200 + 200 kOhm internally so perhaps not.

[@JulianIlett]

+Marcus Nox No, I've checked it thoroughly. The JST is in parallel with the input pins.

[@NoxMarcus]

+Julian Ilett Yepp, you're right. Found this nice write-up: learn.sparkfun.com/tutorials/ltc4150-coulomb-counter-hookup-guide

[@TechnocraticBushman]

+Julian Ilett It's a shunt resistor. That's how you measure current. Ohm's law: I = U/R. R = 0.05 and from the spec, it says VSense + - Vsense- can be between 50 mV and -50mV so it's 1Amp tops. And at 1 amp, i2r = 20mW. PS: An electron has a charge of 6.02 * 10^-19 Coulombs. So that basically counts electrons.

[@gurvinderkaur9181]

can i attach aux

[@hannonm]

TF, "thin form"

[@danielhorne6042]

1:40 i got 5 of them they do make a 300w subwoofer move as i tested they go quite loud as well

[@danielhorne6042]

and the micro usb dosnt have a charger / battery protect so you need a external usb 18650 charger with protector

[@danielhorne6042]

the 3.5mm jack is output not input the amplifier is a 3w lol

[@cbm80amiga]

Regarding MP3 module - it's cheaper and better to buy nano mp3 player from eBay or Aliexpress. It is less than $1 and includes additionally small LiPo battery. It doesn't have USB drive playback capability but for most cases TF/microSD card is enough.

[@MCsCreations]

Those MP3 players are garbage. They don't have random mode and it's really hard to change folders. :/

[@JerryEricsson]

I have been studying up for my HAM test, one of the sample questions is something about a coulomb so I figure it has to be something to do with capacitor, kept getting that question wrong, now I understand why. Funny I usually learn a lot from each of your videos please keep up the great work. I especially love your post bag's however my wife cringes each time she hears you saying that as she knows something will be coming from China in a few weeks! I now am surrounded by things I have built because I watch your videos as they are posted. That said, please keep up the great work. Much better then watching TV with all the crap on there now days. Not a thing educational unless you watch some of the upper channels, and mostly sex and liberal hog wash on day time TV.

[@jennibgmailcom]

I find that a silver sharpie is better than graphite from reading text like on that chip..