CM3-Panel-7-poe technical documentation Buy

CM3-Panel 7 POE - Raspberry Pi Panel PC for building automation and industrial UI

Panel PC based on Raspberry Pi Compute Module 3+ tailored for Building Automation and Industrial User Interface applications

CM3-PANEL-7-POE is an enhanced version of the popular CM3-PANEL with a larger set of interfaces.


Main features

  • LCD TFT 7 inch
  • Resolution: 800 x 480 pixel
  • 10 points capacitive touch
  • Socket for Raspberry Compute Module 3+ normal or lite
  • Socket for MicroSD
  • MIPI connector for Raspberry Pi Camera
  • Placement for USB WiFi PCB module @ 2.4/5.8 GHz
  • 3 USB Hosts
  • 10/100 Mbps Ethernet port
  • Power Over Ethernet
  • RS485 / RS422 / RS232 port selectable by dip-switch on RJ45 connector
  • 1 Relay
  • PCM5122 Audio stereo DAC 384kHz 32bit audio out
  • SuperCAP based power safe circuitry to avoid filesystem corruption on power failure
  • RTC with backup battery
  • Operating temperature: -20° - +70°
  • Power supply at extended range of 12V to 48V DC

Size comparison

CM3-Panel-7-Basic vs CM3-Panel-7-POE

Cm3-Panel-7-POE is an enhanced version of CM3-Panel-7-Basic. Following are the main differences between these two products.

CM3-PANEL-U CM3-PANEL-W CM3-PANEL-7-POE Raspberry Pi 3+ with 7 inch display
USB hosts 1 0 3 4
Wifi 2.4GHz no yes optional yes
Wifi 2.4/5.8GHz no no optional yes
RS485 / RS422 / RS232 no no yes no
Relay no no 1 no
Ethernet no no POE yes
Safety power down no no yes no
RTC with backup battery no no yes
Audio out no no DAC Stereo 384kHz 32bit PWM 16 bit

Power supply section

There are two ways to provide the power supply to the CM3-PANEL-7-POE.

  • Through the Power Over Ethernet connector (Up to 48 VDC. Mode A and Mode B are supported)
  • Through the separate power-in connector (from 12VDC to 48 VDC)

On board buttons

  • A cold reset button (P1)
  • A Shutdown and Restart button (P2)

Serial debug port interface

The debug port interface is used to have access to the system console at the lower level possible. This port works starting from the very first bootstrap phase up to the Linux command line shell.

The debug port works also without active network but it needs to be activated adding this line in /boot/config.txt file:


and adding this line in /boot/cmdline.txt file:


The default serial speed is 115200,N,8,1. The signal levels are at 3.3 Volt.

An USB to 3V3 serial converter is requested to link this port to your computer.

As serial terminal software it can be used:

RS232 - RS485 - RS422 serial port

A serial port visible as /dev/ttyAMA0 is available on the RJ45 connector described below.

The physical interface used is a Max Linear SP335 IC that can be configured alternatively via dip-switch as:

  • RS232 port at ±12 volt
  • RS485 half duplex
  • RS422 full duplex

GPIO Lines

Some GPIO lines are available for user purpose on two 8x2 pin headers pitch 2.54mm

On these pins are also available the power supply lines at 5VDC and 3.3VDC. The signals level of any logic line is 3.3 volt. Don't plug boards with 5 volt line voltage to avoid damage to the Raspberry Pi CM3 module.

Seedstudio Grove, Sparkfun QWIIC and Acme Systems A-BUS connectors

Up to three serial connection systems can be used with the CM3-Panel-7-POE. This feature enable the use of a wide ecosystem of small modules


Power safe supervisor

A Microchip ATTiny88 microprocessor is mounted on the CM3-Panel-7-POE to monitor and manage the power supply and power safe circuitry.

This chip performs many management tasks including:

  • Power state monitoring
  • Charge state of Supercap
  • Raspberry wake-up after a touch event

For the first factory default firmware programming a ICSP port is available. After that the ATTiny firmware can be changed directly by the Raspberry Pi module.

For more info please read this article:

  • Article under construction

USB Ports


MicroSD socket

Raspberry Pi cam MIPI connector

Real Time Clock

Audio out interface


Introduzione alla CM3-Panel 7 POE (only in Italian sorry...)

Mercoledì 31 Marzo 2021 – Ore 21:30

Officine Robotiche ( ha organizzato un evento in live streaming su Youtube dove:

  • Amedeo Asquini (progettazione hardware)
  • Roberto Asquini (progettazione hardware)
  • Mauro Tocci (progettazione firmware)
  • Sergio Tanzilli (definizione delle specifiche del prodotto)

hanno presentato la nuova CM3-Panel 7 POE. Il Panel PC Power Over Ethernet basato su Raspberry Pi Compute Module 3+ disegnato per applicazioni di domotica e automazione industriale.

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