Thank you Steven and Brian for your suggestions.
I tried connecting with Easel, but setting up the machine doesn’t work. It says “plug the USB and start your machine”, so I do, but it doesn’t do anything. Actually, the gShield LEDs start flashing and I can hear the NEMA motors do a silent “thud”, at a pace of about once every 3 seconds.
I unplugged everything, then re-plugged and tried with Universal g-code sender. It worked! I see I have grbl 0.9a installed, though. I thought I updated it to another version back in 2014 ??? So I’m wondering… EDIT I successfully updated to 0.9g, UGS shows this version now. I noticed that there are also versions 0.9i and 0.9j but I’m not sure if I should go there…
For use with Easel, is there a minimum grbl version to have? Any suggestions on this?