Please check I've got this right?

I’ve made a schematic the main thing is I want to check is if I have the ds3231m IC connected correctly. I had interpreted from the schematic of dfrobot. I’ll post the dfrobot schematic then mine which connects to an esp32. Please check that I’ve got it right or wrong?

Your circuit looks nothing like a recommended circuit, another one which you can also find on the first page of the Maxim datasheet. You have shorted SCL and SDA together and connected them to Vcc, and then you have 100k resistors to the ESP32, when they are meant to go direct to ESP32 pins. Won’t work.

Thanks, how about now?

Nope, your still have the resistors in series. They are supposed to be pull-up resistors and also much lower in value, somewhere between 1 and 10k as a rule of thumb.

You’ll need to develop the ability up see if two schematics are topologically equivalent.

And go for the official documentation wherever possible, in this case the Maxim datasheet, rather than a secondary source. The schematic on the datasheet shows a master processor.

Thanks again, I think I understand now after looking at the maxim datasheet.

That’s better, but remember you can use multiple +5V symbols (for example) and they connect together automatically. Also you can connect things by labels, which would make sense for the SDA and SLC lines as these long winded wires look awkward. On the other hand it would probably look cleaner to replace the 3 GND symbols at your LM1117 voltage converter with a single symbol.

I’d also recommend watching this video. Some good tips on creating readable schematics.

There are many points to be addressed in your schematic and while it might function correctly, its very difficult to read. On a simple schematic it’s not such a concern but as they get more complicated it will become prone to errors.

One thing that really gets to me is the GND symbol facing up :slight_smile:


Thanks, I’m just trying to make sense of how it all connects together, I will tidy it up though.

Thanks for the tips, the downside up ground symbol was a joke, I was waiting for a comment on that…

After a tidy up, how does it look?

I would also learn how to use your operating systems ‘screen capture’ utility or install one. Photographs of the screen don’t always show important details well - for instance it would be difficult to see unconnected wires.


Noted, it’s a painful process though as I’m posting via phone and I need reading glasses as I struggle to view the laptop screen and my external monitor is in use elsewhere.

Check on the RESET pin. On the original diagram it might be connected somewhere via the label. Otherwise if its not used then you need add a X (Not connected)

Screenshot from 2022-01-07 14-04-16

Also some more cosmetic stuff. Reverse this so ground is on the bottom and + on the top which is the standard.

This here:
Bildschirmfoto von 2022-01-07 15-08-12

could have a much simpler layout, maybe like this:
Bildschirmfoto von 2022-01-07 15-12-25

It’s usually a good idea to keep signals horizontal, straight (and going from the source left to the destination right if directional and reasonably possible) and route pull up/down resistors, caps and so on perpendicular to that (up if to a voltage, down if to ground). As a very simple rule with some exceptions of course.

After another tidy up;

You’ve introduced an error. Now VBATT Is not powered but connected to GND.

And the +5V from the regulator shouldn’t be pointing downwards for a similar reason to GND not pointing upwards.

Thanks for that, I’ll rectify.

Hopefully this is correct.

Looks better. I quickly put something like this together. Again, cosmetics, but try to get voltage symbols / resistors etc to line up, symbols in the middle between 2 lines. Just makes it easier when someone else is looking over your work (Or when you next look at the schematic in a few years time wondering why you did things a certain way)

Yes you’re right, I’m thinking of point to point wiring as a layman, i will tidy it up tomorrow.

Thanks all for the tips and advice, really fantastic of you all.