The CM3-Home board will be presented for the first time at Maker Faire Rome 2017 - December 1-3, 2017.
On the CM3-Home mother board we have integrated the following interfaces:
Like the Raspberry Pi 3, this module comes with a Broadcom BCM2837 Microprocessor, 1.2GHz clock and 1GByte of RAM memory and is fully compatible with it, but its availability has been going on for years to ensure the continuity of industrial productions that make use of it.
As written in the official module datasheet: " Raspberry Pi guarantee availability of CM3 and CM3 Lite until at least January 2023 ".
As like as the Raspberry Compute Module 3 also the CM3-Home mother board is suitable for the business to business market. On this site it is possible to buy the empty CM3-Home mother board as single piece or in bulk packages of 10-50-100 etc pcs or even just the PCB. For MOQ of 1000 pcs it is also possible to order the PCB in any color or with a custom silk screen.
The typical customers of this board are:
Acme Systems will not provide ready-to-use microSDs or support to install popular software on this mother board but just the basic info about the small differences between the standard Raspberry Pi 3 and the CM3-Home/Raspberry CM3 to understand how to use them with standard software.
A Siemens TP-UART-2 is integrated on-board to provide an electrically isolated bus compatible with some commercial KNX devices.
CM3-Home is not a certificated KNX device so we can't warranty the fully functionality with all the KNX devices.
The CM3-Home doesn't provide the bus power supply so an external KNX power supply is requested to operate. The TP-BUS signals are available on two screw terminals. Detailed info on how to integrate the KNX bus with Raspberry Pi is available on this link.
The TP-UART-2 is wired on the serial port /dev/ttyAMA0 and is compatible with the open source software knxd (https://github.com/knxd/knxd).
This is another type of twisted pair bus electrically compatible with some commercial DALI devices.
CM3-Home is not a certificated DALI device so we can't warranty the fully functionality with all the DALI devices.
The bus is opto-isolated from the CPU side but is in common "electrical domain" with the RS485 and the dry contact inputs.
The data bus power supply is provided by the CM3-Home so up to 16 devices is not required an external power supply. The Light bus is managed in GPIO bit banging. More info is available on this link.
Two separated RS485 buses are available on 6 screw terminals.
The signal are A, B and GND and are opto isolated from the CPU side. The buses are not opto-isolated between them. They are in the same "electrical domain" of the dry contact inputs and light bus interface.
Through this bus you can connect DMX512, Modbus and other generic RS485 devices using the serial lines on /dev/ttyUSB0 and /dev/ttyUSB2 provided by the FT4232 chip.
Grove is a modular, standardized connector prototyping system made by the company Seeed studio.
On the CM3-Home board are available 2 Grove connectors compatible with the 3.3 volt level I2C and GPIO Grove modules:
Two dry contacts inputs with a common line is on 3 screw terminals.
This lines are opto-isolated from the CPU side and are in the same "electrical domain" of the RS485 and light bus interface.
The line status are read trought 2 GPIO line on Raspberry Pi.
The board will be available in two versions.
- CM3-Home lite edition
- This is a cheap version with the basic interface suitable for the most part of residential installations
- CM3-Home full edition
- This is a full featured version compatible with some commercial lighting systems and some energy harvesting Radio ISM nodes.
These main differences between these two version are:
|Hardware description||CM3-Home full||CM3-Home lite|
|Vertical Sodimm socket for Raspberry Pi Compute Module 3||yes||yes|
|Vertical socket for microSD||yes||yes|
|Microchip LAN9514 chip||yes||yes|
|USB 2.0 host ports||2||2|
|WiFi module 2.4GHz||yes||optional|
|FTDI FT4232 chip (4 serial ports from a single USB)||yes||yes|
|Stereo audio out on 3.5 mm jack||yes||yes|
|MIPI camera connector for standard Raspberry Camera||yes||yes|
|Serial debug port @ 3.3 volt on strip||yes||yes|
|Generic serial port @ 3.3 volt on screw terminal||yes||yes|
|Low voltage relay contact||2||2|
|Clear contact inputs on screw terminal||2 isolated||2 not-isolated|
|IR receiver @ 38KHz||yes||optional|
|Seeedstudio Grove connector||2||1|
|RS485 on screw terminal||2 isolated||1 not-isolated|
|Internal connector for 2.2 inch SPI TFT display (320x256) with resistive touch||yes||optional|
|1-Wire bus on screw terminal||1||1|
|Siemens TP-UART chip for twisted pair commercial home automation bus||yes|
|Isolated DC/DC converter||2|
|Light bus for commercial dimmerable ballast on screw terminal||yes|
|Yarm radio module (Yarm) (Microchip SAMD21 + ATA8510)||yes|
|ADC lines on screw terminal||2|
CM3-HOME board has been designed to be enclosed inside a 9 module DIN RAIL case made by ELBag: