This is my first ever post here. Also my first steps into Kicad and PCB design. I’m not a “good electronics engineer”, but i know how stuff works.
I had an idea of making an alarm clock that integrates neatly with Home Assistant. The idea is the following:
BME280 for temperature (and humidity… but not needed actively)
LDR to limit the brightness of the LCD when it gets dark, bright during the day)
Buzzer for those who don’t want the next part
max98357 I2S DAC + amp which can drive a small speaker. Currently in my breadboard setup i use the PCM5102 and a PAM8603)
2 buttons, fully configurable in home assistant to snooze, open/close curtains, control lights… whatever you want, configurable in home assistant. Uses the internal pull-up, so not on the schematic)
USBC powered (with ESD module for safety as well as a ams1117-3.3V linear regulator)
a 1W (max) LED, driven by a mosfet, dimmable throuwh PWM by the ESP32
wireless charging pad on the top, so i can (very slowly, 5W max) charge my phone over night. This is ordered, not in the schematic as it just requires 5V from the USB-C port)
other features are welcome… maybe a 3rd button?
So the plan:
I put it all on a breadboard and it all works (noise issue on the PCM5102, but working on that)
i have the code working on esphome for everything above, but not with the “right” mosfets/…
Next steps:
getting the circuit built in kicad see attached
create a PCB from it:
but this is where it gets horribly difficult. I have no idea where to best put the LED, as it has to be on the side of the clock, the BME280 has to stay “outside”, the LDR needs to extend throught he enclosure, where do the buttons come out, …
once i have the design, i’ll hop into fusion 360 to design an enclosure where it all fits, assemble all and… i’m done.
Now… i don’t have ANY SMD soldering material, no idea which components to use/are best. Example: which MOSFET, which ESD, which type/size/… resistors/capacitors? the LED will use max 300-350mA when it drops 3V. DId i make the correct electronic connections/protections/decoupling/…?
So… how do I go about this? The schematic is attached and… i hope someone will/can help me make this a success and i can just make the whole project, incl gerber files, … freely available, including the 3d print designs, to all interested people.
Or am I doing it wrong here and should i just build in the things, wire it up with cables and forget the PCB idea?
As RaptorUK already mentioned, this forum tries to limit itself to questions on how to work with KiCad, and not for general electronics.
You also did not attach the schematic, but only the project file.
Yes, that is a bit confusing. I’m not entirely sure what the scope of that section is myself.
I don’t know what your project looks like, but I guess its a ready-made ESP32 board, combined with some extras to make it work. some sort of power supply or batteries, maybe a display and a relay output. Such one-offs are quite easy to build on matrix (Vero) board. And especially if you do not know what you want to put into your project, starting with a breadboard is a good idea. ESD is always a concern, ESP32 pins are quite fragile. On matrix board, I also always use sockets, because it lets me quicly exchange IC’s (or modules) when I suspect ESD or other damage.
My current method for such projects is to:
Create a KiCad project and schematic.
Test some things on a breadboard if you’re not sure how (or if) some sub parts of a project work.
Draw a partial PCB. The intention is to plan the footprint placement, and have a general idea of where all the wires go.
Transfer that footprint placement to matrix board, and hand solder the wires.
For simple projects, going through all the fuss of designing a “proper” PCB is not really needed, and it’s more work (and time, with ordering PCB’s and such) then just soldering some parts together. But this has it’s limits. There is no proper GND plane and this makes EMC compatibility problematic. I always use some kind of inductor for the power input (either an SMPS module, or separate inductor). and all wires going off the PCB are antenna’s that both radiate and pick up noise. Getting stuff on a matrix board to work reliably is a bit of a challenge, but it can be done. I have projects soldered together on matrix board (with 0.2mm enameled wire for signals. 0.4 mm for power) that are running for 15+ years.
This is the popup that appears when you hover over the Project category in the hamburger dropdown.
So it should be tightly coupled with KiCad. If the question is equally valid with another ECAD program, then it’s not KiCad specific. For example you mention choice of components and positions of components. You would have to do that with any PCB design tool. That you happened to pick KiCad as your tool doesn’t mean it’s KiCad specific. But if you are encountering a problem doing something in KiCad, then by all means use the appropriate category.
We all love to help but unfortunately answering general electronics design questions would open the floodgates. There are other forums where design questions can be discussed, such as EEVBlog.
As the forum gains traction, we try to get a little more Kicad specific. As you will note on EEvblog, things can get pretty ‘verbose’ in a hurry. We just don’t have the cycles to deal with as much content.
We just don’t have the cycles to deal with as much content.