emonVs power plug for Bermuda

digitalshaman · 20 March 2023 19:57

We’re working on an install of the emonTX (V4); emonBase; and emonVs (ordered without plug) in Bermuda (single phase).

This will replace an earlier installation of emonPi + emonTX + AC2AC (voltmeter).

The emonVs was ordered without a power plug: it looks like the power for the new installation will need a plug, else extra work to source power to the emonVs, or power for the system comes from where?

Would a emonVs with plug be an easier fix? A US-type plug would be needed for Bermuda: can I simply use a conversion plug from UK or EU to US/Bermuda?

Thank you in advance.

PS We’d like to move to actual encryption with keys - not a fixed key or cryptography XOR fixed key on the device & would gladly offer additional data security to interested folks.

glyn.hudson · 20 March 2023 20:09

A converter plug will work fine, just ensure you use one that connects the earth wire. Or you order the version without a plug and hard-wire it via a 3A fused spur or 6A MCB.

@TrystanLea can advise on encryption. Currently, I believe encryption is done via a fixed key in the firmware:

github.com

openenergymonitor/emontx4/blob/main/firmware/EmonTxV4/EmonTxV4.ino#L231


      
            // ---------------------------------------------------------------------------------------
          
          
  if (EEProm.rf_on)
            {
              #if RadioFormat == RFM69_JEELIB_CLASSIC
                rf.format(RFM69_JEELIB_CLASSIC);
              #endif
              
              // Frequency is currently hardcoded to 433Mhz in library
              rf.initialize(RF69_433MHZ, EEProm.nodeID, EEProm.networkGroup); 
              rf.encrypt("89txbe4p8aik5kt3"); // ignored if jeelib classic
              delay(random(EEProm.nodeID * 20));                                 // try to avoid r.f. collisions at start-up
            }
            
            // ---------------------------------------------------------------------------------------
                
          #ifdef EEWL_DEBUG
            EVmem.dump_buffer();
          #endif
          
          
  double reference = read_reference();

digitalshaman · 21 March 2023 14:49

Thank you, Glyn

Robert.Wall · 21 March 2023 15:02

Perhaps not obviously, the same hard-coded key must be used throughout - in every device sharing the radio network.

digitalshaman · 21 March 2023 15:27

Naturally. Plus, the node is predetermined at 17. We intend to secure the sign-in & the packet stream independent of the fixed key.