M0dularis+

M0dularis M+
M0dularisM+ Controller with µBCU
Developer	Alexander Christian
Status/Current Version	Version 1.0 already works
µC	Atmel/Microchip SAMD21G18J
KNX	Siemens BCU / Micro BCU

Description

Controller-Board, mainly designed for OKW 4TE REG case, but also useable with anything else that fits. Can be used with Siemens BCU and Eugen's µBCU. Uses the powerful SAMD21 microcontroller from Microchip/Atmel and has optional I²C EEPROM and SPI Flash.

Hardware

Application Connector

				Description	Pin	Pin	Description
				GND / KNX GND	1	2	GND from 24V Input
				VCC	3	4	24V from 24V Input
	TX3		PA22 / SDA	SDA / IO0	5	6	IO3	SJ: PA19/D12 od. PA02/A0	MISO1	RX1
	RX3		PA23 / SCL	SCL / IO1	7	8	ExtINT Application / IO2	SJ: PA18/D10 od. PB09/A2	SS1	TX1
SDA2	RX2	MISO2	PA09 / D3	Option0	9	10	Option7	PA17 / D13	SCK1	RX1	SCL1
SCL2	TX2	MOSI2	PA08 / D4	Option1	11	12	Option6	PA16 / D11	MOSI1	TX1	SDA1
		SCK2	PA15 / D5	Option2	13	14	Option5	PA20 / D6
		SS2	PA14 / D2	Option3	15	16	Option4	PA21 / D7

You can decide via solder-jumper between

• IO3: D12 or A0
• IO2: D10 or A2
• Application connector: 5V and 3.3V on
• Frontend connector: 5V and 3.3V on
• I2C (on IO0/IO1): PullUp or No PullUp for

OnBoard Connections

• ProgButton*: D15 / A1 [EIC8]
• ProgLED: D19 / A5
• BCU Save*: D17 / A3 [EIC4]
• BCU Reset*: Solder jumper for connecting SAMD-RESET and BCU-RESET Pin
• ExtInt TOP*: D38 [EIC13]
• SPI Flash
  • CS: D9
  • DO/IO1: PA12 / D22 MISO
  • DI/IO0: PB10 / D23 MOSI
  • CLK: PB11 / D24 SCK

\* = PWM capable

Software

How to use SPI Flash

I recommend to use this SPI Flash Library: https://github.com/Marzogh/SPIFlash

You need to explicitly tell the library the CS-Pin:

1// set CS pin to D9
2SPIFlash flash(9);

For testing, you can use https://github.com/Marzogh/SPIFlash/tree/development/examples/TestFlash and modify the said line to use the custom CS pin D9.