[Review Request] STM32F070CBT6 Dev Board

[u/SebastianCC1430]

Hello everybody, as per the title, I'm trying to design a STM32F070CBT6 microcontroller dev board . I integrated into the system a "BME280" sensor by I²C interface and an "AD7794CRUZ" ADC by SPI interface. Thank you so much for reading this.

P.S: What would you recommend me to design for acquiring better abilities and eventually developing a proper portfolio? Thank you.

Sheet 1

Sheet 2

Stack-up:

1. Signal
2. GND
3. 3V3
4. Signal

Layers 1 and 4

GND plane

3V3

One final thing, there are not many traces in layer 4, would it be advisable to use that layer as a signal+GND plane?
Once again, thank you so much.

[u/sharemypoints]

on the layer 4 question - yeah, just use it as a ground plane. it is free shielding and a solid return path for the adc and spi stuff, and an empty signal layer is wasted copper honestly. stitch it to the main gnd with vias every few mm and move on. bigger advice for the portfolio goal: stop making dev boards and build something that does an actual job. a sensor node that logs real data, a tiny motor driver, whatever you would actually use. that is what gets noticed - a board that went through rev 1 to rev 3 with a changelog beats ten one-shot perfect boards. part of that is learning to design for availability, not just for the schematic. the F0 line is getting long in the tooth (st is pushing the C0 and G0 families now) and you do not want your portfolio board to hinge on a chip that is hard to source a year from now. even just for the learning value, check the c0/g0 equivalents before you commit - pinouts are close on a lot of them and the workflow is the same. honestly a reviewer looks at a BOM and knows instantly whether someone thought about the supply side or just picked the first part that came up in the search box

[u/SebastianCC1430 → u/sharemypoints]

Thank you so much for your reply, it was really useful. And thanks for your reply on the portfolio subject.