5 Electrical Connections

TWI

To connect a MSL as a TWI slave to AVR master (megaAVR or XMEGA), pull up SDA and SCL lines with a 10kΩ resistor as shown in the figure below. In this figure, R1 and R2 are 10kΩ resistors. Devices 1 to n are multiple MSL TWI slaves.

Figure 5-1. TWI Connections

SPI

To connect an MSL as an SPI slave to tinyAVR SPI (or USI) master, do not pull up MISO, MOSI, SCK, or CSB, but add a 33Ω series resistor on MISO between the AVR and MSL as shown in the figure below.

Figure 5-2. SPI Connections