3.4.3.2 mikroBUS 2 Connector

The second mikroBUS 8-pin female header (J12) implements all mikroBUS features as described in the schematic below.

The reset feature is ensured (by default) by the processor reset line and can be controlled by the general reset line by swapping R198 and R199.

Figure 3-40. mikroBUS 2 Interface

The second mikroBUS interface features an SPI bus shared with the first mikroBUS interface. Each interface has its own Chip Select line to its SPI interface (PB7 for the mikroBUS 2 interface). I/Os in common are PB3, PB4 and PB5. That means that the SPI interface cannot be used at the same time on the two mikroBUS interfaces.

The second mikroBUS interface features a two-wire interface (PC18 and PC19) shared with the first mikroBUS interface and with a 40-pin RPi connector. The end user must take care of the I²C addresses used on this nodes.

The PWM feature of the first mikroBUS interface (PD20) is shared with the blue LED control.

Table 3-31. mikroBUS 2 Connector J12 Pin Assignment
FunctionPIOMbus SignalPin No.Pin No.Mbus SignalPIOFunction
Analog inputPD1AN116PWMPD20PWM
ResetnRST_MBUSRST215INTPC20Interrupt
SPI Chip SelectPB7SPI_NPCS314UART_RXPC24UART receive (Mbus output to SAM)
SPI clockPB5SPI_SPCK413UART_TXPC23UART transmit (Mbus input from SAM)
SPI MOSIPB4SPI_PISO512TWI_SCLPC19TWI clock
SPI MISOPB3SPI_MOSI611TWI_SDAPC18TWI data
VCC --3.3V supply7105V supplyVDD
GROUND --GND89GNDGround