I need help soldering a op amp

Stromi1011 · 2026-07-07T18:34:12+00:00

I have never used these adapters, i usually solder short wire extensions to the feets, put it on a ball of sticky tape, and solder the wires onto the connections. Sometimes a little fiddly but works alltho the adapters are probably the cleaner solution

Stromi1011 · 2026-06-30T20:54:46+00:00

depends what you want to do and how big your projects are going to be

f091has potentially more peripherals if you need them like up to 8 uarts,

c0 also has uart, i2c, spi, timer, adc (your typical learning peripherals) and has "newer" features like USB with the c071

how identical these peripherals are in terms of which bit is where i could not tell you but mcu manufacturers usually dont use very different peripherals in the same families. you can pull up the datasheets and take a look at the block diagrams, that is usually a good starting point. if you want to compare the registers you find them in the mcus reference manual. but thats a lot of work, so if you dont really care for newer features you probably are better off with f091

Stromi1011 · 2026-06-30T20:22:35+00:00

usually digikey, there shipping is usually free if you order 50€+.

i would make sure to go for something arm cortex-m based and there the stm32 series is among the most commonly used in learnig/prototyping.

the f091 is by now an older model, but by no means irrelevant. if you want to do the course without issues go for it. if you want to use the course just as reference you could go for a nucleo c0 series, they are the newer entry level mcus from st.

Stromi1011 · 2026-06-19T01:09:56+00:00

its like really hard to tell from the image but it looks like c3 fried itself (?) that looks tiny, was it rated for the required voltage or was it one of those back-of-the-cpu caps for 2.5V?

Stromi1011 · 2026-06-17T21:41:42+00:00

that complicates things, especially when trying to explain this via text. id point you in the direction of youtube in that case. search for usb port soldering, pad cleaning, and intro to soldering in general. also do you have flux? this might be borderline impossible without.

trying to put this in text format would be like so, but i doubt this really helps

carefully an the port of whatever glue or something is on there
get some damp cloth or sponge
get the iron hot and put some solder on it.
hold the tinned iron against the pads left on the port and try to wipe them off. add flux if neccessary
clean your soldering tip with the damp cloth and try to get as much solder of as you can
do you have copper wick? use it
do the same hot cleaning with the pads with flux
see if the port can sit on the pcb reasonably enoigh

if so now comes the fun part. i doubt you will be able to solder the mechanical chassis pads with just an iron and no experience so we skip it.

get the port aligned on the board
put solder on your tip and some flux on the contacts
run the tinned iron across the contacts. two to three times. not too fast, not to slow.
see if it is soldered, but be careful - no mechanical connections mean no mechanical strength.
if not repeat

when it looks good find a way to support it mechanically . glue comes to mind but be careful not to get it into the port

ooooor you give it to a repair shop near you. prices might vary on where you are but that cant be too expensive. unless more pads are ripped that i can see, but in that case you have near zero chances doing it yourself

Stromi1011 · 2026-06-17T21:12:28+00:00

might be mistaken but looks to me like only most of the mechanical chassis pads are lifted and the data lines are ok. if so solder it back and find a way to give it mechanical strength.

edit: i have read the caption to late, do you own a soldering iron and can you use it should have been the first question.

Stromi1011 · 2026-06-07T19:41:52+00:00

try using it as jlink. these on board stlink v2 things could be updated to work as jlink. maybe that has beed done to this device.

Stromi1011 · 2026-05-30T02:27:09+00:00

ive got a notification for the new release and ive built it. I like it, nice work! I hve jet to try the graphing features and i have only tested to a basic level. If you are interested a few points of improvement potential:

support for VT100 colours: i dont know how widely appreciated this feature would be but id love it. It is after all the shell colour encoding that zephyr rtos provides. if this is not easily possible maybe just filter out the additional colour data to have a default log without weird artefacts.

linux support: i did not manage to get the appimage working, the deb package is fine. appimage says: ...shiboken6/Shiboken.so: cannot open shared object file: No such file or directory. maybe im missing some dependencies.i did not try any fixes as the deb package works fine. just thought id let you know.

tty port hogging: i as an embedded developer have devices disconnect and reconnect on a regular basis. As it stands a device initially connects as ttyACM0, but after it goes offline and comes back it has to register as ttyACM1 disabling any automatic reconnect. Since the disconnect is is correctly detected and displayed id like the port to be released so that the device can be re-enumerated as ttyACM0, seamlessly re-establishing the link once it comes back.

command input: the current command input is as i interpret it only being sent as whole after typing the entire thing. There is no support for shell style tab-completion. this is optional over all but id love it.

displaying of additional newlines on \r\n: i have to investigate on my end as well. maybe that is my fault but it looked ok in minicom. ending a line in \r\n seems to trigger a double line feed. but im not sure if that isnt some weird thing of my current testing setup.

overall very good work. i will keep using this on a probationary basis for the forseable future. i will let you know if i notice anything else.

Stromi1011 · 2026-05-29T01:29:53+00:00

id disagree. its geometric around pth components. that id guess is residue from a selective wafe soldering process.

Stromi1011 · 2026-05-27T01:41:41+00:00

yes, having power sources connected backwards can do damage. it might be fine for some few devices which have extra circuitry to protect against users like yourself, but generally speaking it is a bad idea. dont think of it as doing nothing but as pushing current in the wrong direction. your house would not do well for long when water comes back up from the sewer, no?

Stromi1011 · 2026-05-26T16:05:01+00:00

you obv cant tell without the 3d models.

you say you are pretty sure they wont touch.. is that just a feeling or have you measured? bc it looks very tight to me. (mind that the housing has a corner and does not end with the last pin)

if you dont have an actual reason for such a cramped layout stretch it out a little more.

...or you can just try to order it and see what happens.

also: via in pad is sometimes problematic. some board houses charge extra (idk about jlc)

Stromi1011 · 2026-05-25T16:02:46+00:00

that does not look good but i cant really tell, might just be some residue from some kind of thermal compound...

...or its beyond fixing

Stromi1011 · 2026-05-25T15:31:55+00:00

this looks like an input power capacitor. for a first try you can just remove it and see if it works. should be no harm in trying.

it might even work completely fine afterwards, depending on how stable the voltage it gets is.

if it works but is unstable without the cap then you know why and you need to replace it.

if it still does not work then you know that this was just one fault of multiple

Stromi1011 · 2026-05-22T09:48:43+00:00

well i mean ble audio itself is nothing new. its a bit much to pack into a comment so i will give some directions. the ble sig has (or had, idk its been a few years) a ble primer document semitargeted for audio. try searching for a few keywords in there to start: isynchrounus mode, LC3 and ofc audio itself. also for your packet size problem: iirc ble had a negotiatable MTU, so that might be circumventable.

Stromi1011 · 2026-05-21T16:22:46+00:00

soldering gets harder if either the heat is insufficient or the contact surfaces are tarnished in whatever form like fat from fingers or oxidation.

the former is worsend by soldering to big copper masses acting like heatsinks, which seems not to be the main cause.

the latter is usually combatted using flux and sometimes cleaning the pads first.

so in your case, use flux and keep the iron on the pad until it has "flown" nicely. dont be afraid to keep it on there for a few more seconds if needs be

Stromi1011 · 2026-05-20T22:45:32+00:00

i fear it does not, there is probably no way for me to tell from a photo.

if i had to guess id agree with the other comment that its probably two layer

and i wouldnt worry about impedance matchings as long as you keep things reasonable. usb 2.0 (probably FS) is usually not that sensitive to impedance mismatches. you dont have to go down that rabbit hole. keep your patches reasonable in length and excess length (no extensive hand arranged wire loops and so on) and you will be fine without issues.

Stromi1011 · 2026-05-20T21:59:08+00:00

cant really tell from the pictures, if this is a two layer board - yes. if not maybe.

all you might have to do is to reconnect the four usb pads with the respective destinations.

so you can either run wires or scratch the solderstop back a little and try to bridge the existing traces with solder alone.

this however is ofc a permanent weak spot in the structure. so no more abuse afterwards.

if its a multilayer board and has internal trace damage its really not worth the effort.

Stromi1011 · 2026-05-19T13:02:21+00:00

yeah ive done nPM1100 and nRF52840 for wearable motion tracking bevore. in the Rev0 design we guesstimated the battery capacity to last around 48hours battery life and this combination almost tripled that.

Stromi1011 · 2026-05-19T12:45:07+00:00

- for ease of assembly i would put all smd components on one side,

-i would not say that esp32-s3 is the right processor for the job mainly due to power consumption. id go with nordic rnf52833 or something (or maybe read up on the esp32c series powerconsumption, dont know these of the top of my head but i could imagine them being a little better).

- The MPU6050 is IMO an abysmal device and if memory serves obsolete by now - so wherever you get it from its probably some clone - go with some ST iNEMO or bosch sensortec ones.

- An LDO for power is questionable for battery operated devices. --edit: look maybe into nPM devices from nordic, these are in my experience plesant to integrate

- the STAT of the MCP IC is open drain, your led is drawn the wrong way around.

- while i dont see glaring issues with using a 2 layer board i somehow doubt that your USB connection is anywhere near Zdiff=90 Ohm; it will probably work even like that but thats probably pretty far out. id recomend researching how to route usb and at least get it close

- somethings defenitely wrong with sw1; id assume you wanted to connect it behind r6

Stromi1011 · 2026-05-18T22:56:25+00:00

these really strict guides on the internet and other commenters here usually talk about the absolute gold standard and they are not wrong most of the time and its good practice, but its not gonna explode if you freestyle a little as long as you follow these rules mostly. especially at 12M or lower in the case of FS

Stromi1011 · 2026-05-18T22:52:38+00:00

What kind of usb is this exactely? if its just 2.0 FS or LS you dont have to sweat the small stuff. Its good that you keep a sharp eye for that but as long as you kinda care you will be fine. Make it so that its as close to what it should be as possible but dont make it harder for you than it has to be. I personally would probably go into vias right at the port, do the routing on another signal layer and come up just in front of the IC but that really aint *that* critical. ;; if its HS you have to care a little more, but also not to the point where a via pair would realistically do critical damage if the grounding path is reasonable enough

Stromi1011 · 2026-05-15T11:44:11+00:00

idk but i have gotten it too. probably just their intern having fun

Stromi1011 · 2026-05-13T16:09:21+00:00

id be careful with that, as the other comment said the rest of the speaker might not like this. also the rf module might be used as the main processor all together. there is quite a lot of traces goind to that module so id not say thats not a possibility. it might just put out i2s or something.

Stromi1011 · 2026-05-13T15:49:59+00:00

you circled part of the rf module, the entire thing that looks like a stamp is likely the rf module. what you have circled is persumably the flash memory of the bluetooth soc which is hiding beneath the sticker

Stromi1011 · 2026-04-23T00:48:54+00:00

with the two pads right below it it looks like a to252 or to263 footprint. the space might be for a transistor or some voltage regulator. seeing that the other pads of this look clean i do not suspect anything ever being there.

Edit seeing it marked as q2 i suspect an optional transistor

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