How to tell my advisor I stopped sending him weekly reports on my results because he was not answering my emails? I have been working on my PhD from home for several months now because my mom is sick, which was fine with my supervisor up until a few weeks ago. Before starting to work from home (in a different country than my supervisor is), we agreed that we would communicate every two weeks and that I would send reports about my progress.

As I did so over the last months, I would rarely receive a response from my supervisor, who is a big name in our domain and is very, very busy. 
After a few unanswered emails, I had the impression that I should just contact him in urgent cases, so I stopped contacting him every two weeks.

Now he is asking me to come back to work at the office because he thinks that I have not been communicating enough in the last weeks.

I am aware that I should not have supposed that he only wanted urgent information and thus I should have continued sending him my weekly reports, but how can I tell him that it is because I never got any answer from his side? 

My wish is to find a good equilibrium in our communication style so that I can continue working from home!
I would say that, like others, you should tell him honestly.
Something to the effect of:

&quot;My apologies for the lack of communication in the past few weeks. I was under the false impression that you only desired my reports in urgent cases, as there were several that you did not reply to. It was my mistake to make that supposition without explicitly asking you. In the future, I very much would like to continue working from home but I also would like to find the best way for both of us to communicate. We can certainly continue a report every two weeks but, in that case, it would be very helpful to me if you would be able to offer me a little bit of feedback for the report. I understand how busy your schedule is but I would truly appreciate it. Please let me know your thoughts.
Thanks,
[Your name]&quot;