ラズパイのPythonの数値（小数点）をArduinoにどうにか伝えたい(SPI or I2C) PythonArduino(SPI or I2C)( < arduino ### 1byteArduinoIEEE754ArduinoArduinobyte(SPI, I2C) str(I2C) bytebyte to Arduino: SPI usbarduinousb

RS232 → PC

`[STX]` ASCII `[ETX]`

`[STX]=0x02` `[ETX]=0x03`

`STX`/`ETX`

SPI `#CS=H→L` `#CS=L` `#CS=L→H`

I2C `[]` `[]`

SPI I2C

SPI SPI 32bit Transaction Payload 8bit 24bit SPI `` `` `X bit0-15`

* * *

RaspberryPI `spi.xfer2` `spi.xfer`

* `#CS=H→L`
*
* `#CS=L→H`





* `spi.xfer2([0x40,0x49,0x0F,0xD8])` (32bit Transaction)
* `spi.xfer2([,0x40,0x49,0x0F,0xD8])` (40bit Transaction)





Arduino SPI `#CS` `#CS` `#CS` 40bit Transaction 32bit Transaction 16bit

see also; RaspberryPi CM4 PythonSPIEEPROM