2021-03-12 01:36 PM
Hello, I'm designing a custom board with STM32F303ZE as MCU. To get started I have downloaded the PCB schematics from the website of the original product: https://www.st.com/en/evaluation-tools/nucleo-f303ze.html
I have made a custom board with ATMega2560 before. For the PCB to function the way I wanted I only needed:
The MCU (of course)
USB-TTL converter to program the board using a USB connection.
Crystal oscillators for the MCU and USB-TTL converter.
And a power supply for the board.
+Passive components (resistors, capacitors etc.)
This project was easy to do because I followed a company's schematic for an Arduino Mega clone, which was a simplified version of the original Arduino Mega board.
But after investigating the schematic for the Nucleo board I have realized there are way more components than the ones I have mentioned above such as OP-AMPs. One thing to note, I know the original Arduino Mega board has extra stuff like that too but I didn't need them for the basic functions. Since the Nucleo board is a brand new topic for me I am not very sure If I need these extra components or not.
My question is as I mentioned above, which components from the original Nucleo board do I need for the custom board to able to read I2C sensor data, use SPI interface RF module and UART interface GPS module.
This board will be a rocket avionics computer so I need to:
Read sensor data from sensors such as BMP280, BNO055
Communicate using RFM98PW (SPI Interface) RF module.
Read data from the Ublox NEO-7M GPS module.
Can I just get away with a USB converter, oscillators and power supply? Or do I need to have the opamps etc. on the board as well?
Thank you for reading.
2021-03-12 01:57 PM
The MCU arguably doesn't need an oscillator.
Perhaps you'd do better looking at the design of the Blue Pill, or other similar breakout boards for a simple/minimalistic design to copy?
Basically just needs power, pull down on BOOT0, pull up on NRST, and connectivity to JTAG
Some other STM32 would provide USB also, but an SiLabs/FTDI interface has simplicity going for it.
NEO-7M going to have a 4G, 25 KM, Mach 1.5 limit
A MAX-M8Q would have similar limitations, but would be smaller, pull in multiple constellations, and sustain 10 Hz solution rate.
A NEO-M9N could get you a 25 Hz solution rate.
Sure you couldn't do this with the Murata LoRa module, has a quite capable STM32L072CZ (192KB Flash), capable of doing LoRa, I2C and GPS/GNSS concurrently.
2021-03-14 08:30 AM
For other STM32 series there is an application note like AN4488: "Getting started with STM32F4xxxx MCU hardware development" It seems that there is no such an application note for F3. If that really is the case, it's still recommended to look at AN4488 for F4, AN4555 for L4(+) and probably other series notes.
2021-03-14 08:44 AM
> Basically just needs ... pull up on NRST
It doesn't. There are some topics in the forum, where too small pull-up resistance causes problems.
> pull down on BOOT0
Or the pin can be connected directly to ground, if BOOT0 functionality is not necessary.