How smart is the Mondaine MSM.25S11 wifi wall clock?

When our classic Mondaine wall quartz clock died after more than twenty years, I really wanted another one. I asked Mondaine if they had a radio clock (that receives a time code transmitted by a radio transmitter connected to a time standard such as an atomic clock). They did not, but they do have the MSM.25S11, a smart wifi wall clock. How smart exactly is this clock? Let’s find out…

I set up network packet capturing on my pfSense firewall with tcpdump to store the network communication by the clock in a file. If you are interested, you can download the Mondaine MSM.25S11 time synchronization network packets.

Some observations:

  • The clock starts moving it hands after fitting the two supplied Varta Ultra Lithium AA batteries. According to Varta, these battery boast a 3000mAh capacity. The hands all stop at 12:00:00.
  • After pressing the two blue buttons on the back, the clock performs a reset and transmits its own wifi network. When you connect to that wifi (with your smart phone or laptop), it shows a web page that asks four your language, time zone, wifi network, wifi password and daylight saving settings. After hitting Save, the clock is ready.
  • The MAC address vendor of the clock 8C:CE:4E is Espressif Inc., so there must be some kind of ESP chip in it.
  • Once every 24 hours the clock performs a single time synchronization over wifi.
  • After getting an IP-address with DHCP, the clock performs a DNS lookup for the host After receiving the IP-addresses, the clock sends an NTP packet to the host, but it did not receive a response in my case.
  • The clock performs a second DNS lookup, this time for the host After receiving the IP-addresses, the clock sends an NTP packet and gets a response. Time sync should have worked and the hands move to the right position on the dial.
  • The time between the first and last packet of a synchronization run is about 7 seconds. Because the wifi is only enabled during this period and only once a day, the drain on the batteries by the wifi communication should be minimal.

Because this clock only uses NTP and queries, it looks to be a future proof product. It is only a bit strange that it first looks up, an NTP server in the Chinese Alibaba cloud. I have added to the blocked IPs on my firewall and time synchronization works perfectly with

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