groov I/O Nodes - Introduction

Overview

If you’re new to Node-RED but have not yet worked through the Hello, world! example, please do so now.

In this section, we’ll add a groov I/O Read node, configure the groov device and address, and run the flow.

Step 1 - Add a groov I/O Read Node

1. Drag out an Inject node, a groov I/O Read node, and a Debug node.
2. Wire them together, as shown below.

Step 2 - Configure the groov I/O device

1. Double-click the groov I/O Read node to open the “Edit groov i/o read node” view. Since this is the first groov I/O node, a groov device configuration must be added.
2. Click the pencil icon to the right of the Device field to open the “Edit groov-io-device node” view.
3. For the Address field, enter the hostname or IP address of the groov I/O device.
   • If using Node-RED and groov I/O on the same device (such as a groov EPIC processor), then enter “localhost” for the address.
   • Do not include HTTPS:// as a part of the address.
4. For the API Key field, enter a valid API key for a user on the groov I/O device. This can be found in the Accounts section of groov Manage on the device.

5. Configure the SSL Certificates fields.

   Note: This step should be skipped if you’re using groov I/O and Node-RED on the same device or computer, such as a groov EPIC processor. In that case, make sure you’re using “localhost” for groov’s address and do not enter anything for the certificates.

   If the groov I/O and Node-RED are on different devices, then you must configure Node-RED to use the groov device’s public key SSL certificate.

   Important: The certificate files need to be on the same groov device or the same computer as the Node-RED installation, as it will open the certificate file directly from the file system.
   • If using a self-signed certificate, then enter the certificate’s filename or full path in the “CA or Self-Signed” field.
     • If using a groov EPIC processor or groov Edge Appliance, just enter the filename of a certificate you uploaded using groov Manage or Node-RED Admin.
     • If using Node-RED on a computer, enter the path and filename of a certificate on the same computer.
   • If using a CA-signed certificate, then enter the CA’s certificate’s filename or full path in the “CA or Self-Signed” field and groov’s public key in the “Public Key” field.
     • If using a groov EPIC processor or groov Edge Appliance, just enter the filenames of the certificates you uploaded using groov Manage or Node-RED Admin.
     • If using Node-RED on a computer, enter the path and filenames of the certificates on the same computer.
6. Click Done to return to the “Edit groov i/o read node” view.

Step 3 - Configure the Read node

To keep things simple, we’ll read from a memory map address that returns the number of seconds since the device was last powered up.

With the “Edit groov i/o read node” view still open:

1. For the Data Type field, select MMP Address.
2. For the Address field, enter 0xF0300160.
3. For the Type field, select UINT32.
4. Leave the Length field empty.
5. Leave the Value field. with msg.payload selected.
6. For the Name field, enter read uptime.
7. Click Done.

Step 4 - Deploy and Run

1. Click Deploy.
2. Make sure the Debug tab is viewable in the right-hand sidebar.
3. Click the Inject node’s button.
4. The Debug tab should show a new message with a large number, which is the uptime of the device.
5. Click the Inject node again, and the number should be a bit larger.

If that worked for you, then your Node-RED installation is successfully communicating with your groov I/O!

Next Step

Continue on to reading a digital or analog channel’s value.