Example Node-RED MCP23017

This is a simple working Node-Red example for a Raspberry PI with an GPIO Port extender MCP23017. It is easy possible to control the MCP23017 with Node-RED.

Here a screenshots from the devices. The description on developer page is not really good. We needed 2 days for the right settings. It is really simple.

The overview Example Node-RED MCP23017

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OpenWRT Read-only file system

OpenWRT Unsaved Changes

Problem: OpenWRT Rooter LeMaker is running on a Banana Pi. Now the modem monitoring system is rebooting the router every 5 minutes without a reason.

Reason: The SD is corrupt – Files System has a problem. We can read this also in the System Log and in the Kernel Log. If we try to install new software in the OpenWRT we get this error:

Collected errors:

 * wfopen: //usr/lib/opkg/info/libext2fs.control: Read-only file system. Continue reading “OpenWRT Read-only file system”

Raspberry Pi with I2C Port expander MCP23017 16 Relay switching

In this example we connected a Raspberry Pi 3 with 3 relay boards via MCP23017 I2C port expander and switch the relays.
You can control 16 relays via MCP23017. Via the I2C port of the Raspberry Pi you can control up to 8 MCP23017 (you can assign 8 different addresses to the MCP23017). So you could easily control 128 relays.

Danger:

The Raspberry Pi does not have enough power to switch 16 relays !! An additional power supply must be connected. We have connected an additional breadboard power supply.
To control the relays with the Raspberry Pi via a port expander MCP23017 must be activated on the Raspberry Pi I2C. This can be done by the raspi-config by command line or via the desktop Raspberry PI Configuration.

Raspberry Pi I2C Enable
Raspberry Pi I2C Enable

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