AttoIO

label	pin	pin	label
GND	19	20	5V
CAN_H	17	18	SPI_CLK
CAN_L	15	16	SPI_MISO
USB_D+	13	14	SPI_MOSI
USB_D-	11	12	USART_CLK
I2C_SCL	9	10	USART_IN
I2C_SDA	7	8	USART_OUT
ADC	5	6	UART_OUT
DAC	3	4	UART_IN
3V3	1	2	GND