mcu-board

Some design notes for an MCU board... Deeply WIP.

Features

1. STM32 Cortex M4 with FSMC (possibility: STM32F413ZGT6 for 144-LQFP, STM32F413VGT3 for 100-LQFP, and STM32F413RGT6 for 64-LQFP)
2. Extra flash and PSRAM
3. WIFI module e.g. ESP32 C3 or ESP32 S3
4. 4 motor control ports (EV3 compatible)
5. 4 sensor control ports (EV3 compatible)
6. Raspberry Pi pin-out connector (enough to communicate with Raspberry pi Zero, does not need full support)
7. SD card (SPI interface enough/SDIO nice to have but requires supported MCU)
8. Accelerometer (could be external)
9. STEMMA QT connector (nice to have)
10. Some informative display (nice to have)
11. A couple of buttons for interface (nice to have also)
12. Lego "compatible" physical shape.

Alternative

• STM32L4R5VGT6 with 640KB of RAM instead of the external ram versions (but it also supports the FMC/FSMC). And it is cheap, and more available than the previous ones. (Or the subtly better STM32L4R5VIT6)

Notes

• The WIFI module with the SD card on one side and the Raspberry Pi connector may not need to be active at the same time.
• The display could be controlled by the WIFI module via AT commands. Other things could be moved to the WIFI module too (the interface buttons, maybe).
• The board would be a Raspberry Pi hat that can work alone. This can be a rev 2 objective, but planning for the space would not hurt.
• Driving external memories with the FSMC, application not AN4761

smaller mcu-board

Features

1. STM32 Cortex M4 - May be

   • STM32L4P5CGT6
   • STM32L4P5CGT6P
   • STM32L4Q5CGT6
   • STM32L4Q5CGT6P all (48-LQFP with 1MB of flash, and 320KB of RAM).

2. WIFI module e.g. ESP32 C3 or ESP32 S3

3. 4 motor control ports (EV3 compatible)

4. 4 sensor control ports (EV3 compatible)

5. Raspberry Pi pin-out connector (enough to communicate with Raspberry pi Zero, does not need full support)

6. SD card (SPI interface enough/SDIO nice to have but requires supported MCU)

7. Accelerometer (could be external)

8. STEMMA QT connector (nice to have)

9. Some informative display and a couple of LEDs (nice to have)

10. A couple of buttons for interface (nice to have also)

11. Lego "compatible" physical shape.