support for CPU with USB ???

A project log for μRetro game console with CPU on fake μSD cards

IT IS NOT ONLY GAME, IT IS NEW DEVELOPMENT INTERFACE. CPU ( attiny85, atmega328 or samd21 ) on fake micro sd card :)

bobriciusbobricius 04/11/2019 at 12:545 Comments

I got a tip from Mr. Vlk to try Microcontrollers with native USB and read buttons via I2C.

Also Attiny85 can be reprogrammed via USB with digispark bootloader !

My fake Micro SD give me 8 wires (list only, not exact pinout):

Maybe in next version I can try this pinout:

With this I can expand offer of usable controllers with etc. SAMD21 or STM32

SAMD21 add now very popular Adafruit circuitpython programming feature ;)

What do you think about it?


RomanS wrote 04/11/2019 at 14:10 point

i use MCP23017 I2C gpio expander in my ESPboy gadget for buttons. Anyway you can put lot of devices on i2c at the same time. I'am not sure that USB will bring something extraordinary... but if you'll put micro usb connector on your console and add D- D+ pins to SD it could expand opportunities. with 2 SD slots you can also add UART and SPI also... But in this case you have to make double SD card PCB to use all this pins in both slots ))

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bobricius wrote 04/11/2019 at 13:24 point

I also thought about this solution, It save I2C chip for reading keyboard. Maybe I can have PCB usb connector on sd card like And 2 parallel SD slots 1. MCU 2. SENSORS

I try draw something ;)

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deʃhipu wrote 04/11/2019 at 14:24 point

You can use my code for attiny24 for the keyboard from #D1 Mini X-Pad Shield — it does debouncing and buffering, and you just read a single byte over i2c.

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deʃhipu wrote 04/11/2019 at 14:25 point

And with a bit of extending, you could also make it play music.

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deʃhipu wrote 04/11/2019 at 13:12 point

Alternatively, you could have the USB connector on the card itself.

In fact, you could even have cards with some additional sensors on them, if the game requires them — light, accelerometer, breath (for an ocarina opp), etc.

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