# IIoT Tools

- [Node-RED](/iiot/iiot-tools/node-red.md): Find all the resources related to our course Node-RED made Easy.
- [Renewing SSL Certificates](/iiot/iiot-tools/node-red/renewing-ssl-certificates.md): If your node-red-contrib-opcua-server has been running for a while and the SSL certificate has expired, here's a clear and practical guide to replacing it with a new one.
- [Node-RED Safe mode](/iiot/iiot-tools/node-red/node-red-safe-mode.md): Many a time your flow caused your Node-RED to crash. And when you restart your Node-RED, it crashes again and makes it difficult for you to troubleshoot the flow.
- [How to format the timestamps](/iiot/iiot-tools/node-red/how-to-format-the-timestamps.md): Sometimes you need to use the timestamps in your Node-RED project. You can use the timestamp node to extract the timestamp like below:
- [OPC UA](/iiot/iiot-tools/opc-ua.md): Resource page for our course Learn OPC UA with Node-RED
- [OPC UA Course](/iiot/iiot-tools/opc-ua/opc-ua-course.md): In this page you will find resources related to OPC UA course available at www.codeandcompile.com
- [Troubleshooting](/iiot/iiot-tools/opc-ua/troubleshooting.md): In this page, you will find troubleshooting techniques for OPC UA
- [Certificate error in Node-RED](/iiot/iiot-tools/opc-ua/troubleshooting/certificate-error-in-node-red.md)
- [MySQL](/iiot/iiot-tools/mysql.md): In this page you will find resources related to our online course named Interface MySQL with PLC via Node-RED
- [MQTT](/iiot/iiot-tools/mqtt.md)