Decrypting the Vado Identity wired shower controller

Projects Discussion and Showcase Device Hacking
5

So, here's what I'm doing:

  • There are no connections between the mixer and the arduino mega. The mixer is plugged into the wall but not switched on
  • Switch the arduino on and open the serial monitor - no output as expected
  • Connect the tx pin from the mixer to the rx pin on the mega - output starts slowly
  • Wait for 5 lines of output then switch the mixer on - output comes fast
  • Wait for the mixer to complete start up noises then turn the mixer off - after 3 lines the output slows down
  • Wait for 5 lines of output then turn the arduino off

And here's the code:

long baudRate = 115200;
byte serialConfig = SERIAL_8N1;

const int lineLength = 100;
int curLength = 0;

void setup() {
  Serial.begin(baudRate);
  Serial1.begin(baudRate, serialConfig);
}

void loop() {
  int inByte;  
  while (Serial1.available()) {
    inByte = Serial1.read();
    Serial.print(inByte, HEX);
    Serial.print(" ");
    
    if (curLength++ > lineLength) {
      curLength = 0;
      Serial.println();
    }
  }
}

The arduino is connected to a laptop which is not connected to a power supply so how am I receiving any signal without a ground connected? Am I therefore just receiving interference?
And when I do connect the ground between the mixer and the arduino I get no output at all.

Is this a step backwards? How can I shield from interference and be sure I'm only getting a signal from the mixer?
Any help appreciated...

The output looked like this anyway:

Arduino turned on

0 0 FC 0 0 0 0 0 0 0 0 FC 0 E0 0 1C 0 0 0 0 FC 0 0 0 0 E0 0 0 1C 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 E0 0 FC 0 0 0 0 0 FC 0 0 0 3 3 0 0 0 FC 0 0 0 0 0 FC 0 0 0 0 FC C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 E0 0 0 E0 1C 0 0 0 0 0 0 0 0 
0 0 0 3 0 0 0 0 0 0 FC 3 0 8 0 0 0 1C 0 0 0 0 0 0 0 0 E0 0 0 0 F0 0 FC 0 0 F0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 70 FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 F0 0 0 0 0 0 0 0 0 0 0 0 0 0 1E 0 0 0 0 0 1C 0 0 0 0 0 0 FC 
0 0 FC 0 0 0 FC 0 0 FF 0 0 2 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 1C 0 0 0 0 0 0 FC 0 0 0 0 0 0 FC FC 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 1C 0 0 0 0 0 0 0 0 FC 0 0 E0 0 1F 0 0 0 0 0 0 0 FC 1C 0 0 0 0 0 0 0 FC 1C 0 0 
0 0 0 0 0 0 0 0 0 C 0 FE 0 0 0 4 0 0 0 0 0 1C 0 0 0 0 0 FC 0 0 1C 0 0 0 0 0 0 0 0 0 0 1C 0 C 0 0 0 0 1C 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FC 
C 0 0 1C 0 0 0 0 0 0 0 0 0 FC 0 0 0 FC 0 0 0 0 0 0 0 0 0 FC 0 0 0 FC 0 0 0 FC 0 0 0 0 0 0 0 0 0 E0 0 0 0 0 0 FC 0 1C 0 0 0 0 0 1C 0 1C 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 0 E0 1C 0 0 0 0 0 0 3E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Mixer turned on

FC 0 0 0 E0 4 E0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FF FF F0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FF FC 0 0 0 0 0 0 0 FE 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 F0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 
F8 0 0 0 0 0 0 0 0 FE E0 C 0 0 0 0 0 F8 0 0 0 0 0 0 0 0 0 0 0 F0 F8 0 0 0 0 0 0 0 0 0 F8 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 FC 0 0 FC 0 0 0 0 0 0 0 0 0 F0 0 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 F0 0 0 0 0 0 0 0 0 0 FF E0 0 0 0 0 
0 0 0 0 0 0 0 0 C0 0 0 0 0 0 0 0 0 0 0 0 0 FF FF F0 0 0 0 0 0 0 FF FF 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 FC F8 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 FC C0 0 0 0 0 0 0 FF FC 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 FE 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 FC F0 0 0 0 0 0 0 0 FE FC 0 0 0 0 0 F0 0 0 0 0 0 0 0 0 0 0 0 FC C0 0 0 0 0 0 0 0 0 FC E0 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 F8 FE 0 0 0 0 0 0 
0 0 FC 0 1C 0 0 FC 0 0 FC FF 0 0 0 0 0 0 0 0 0 0 0 F8 F0 0 0 0 0 0 0 0 0 0 FF F8 E4 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 F8 0 0 0 0 0 0 0 0 0 FC C0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FF 0 FF E0 0 0 0 0 0 0 0 0 0 0 FF FF F8 0 0 0 0 0 
0 0 0 0 0 0 0 FE 0 0 0 7 0 0 0 0 0 0 0 0 0 F0 F8 C 0 0 0 0 0 FE FF 0 FC 0 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 0 FF F0 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 F8 0 0 0 0 0 0 
0 0 0 0 0 0 FE FC C0 38 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 FF E0 0 0 0 0 0 0 0 FF F8 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 FC F8 0 0 0 0 0 0 0 0 FE FF F8 FC 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 FC F8 0 0 0 0 
0 0 0 0 FF FC 86 0 0 0 0 7 0 0 0 0 0 0 0 0 0 0 0 0 F0 FC 0 0 0 0 0 0 0 0 C0 0 0 0 0 0 0 0 0 0 0 0 0 0 FF 0 0 F0 E0 0 0 0 0 0 0 0 0 0 FC F8 C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 F0 0 0 0 0 0 0 0 0 0 F0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 F0 0 0 0 0 0 0 0 0 0 0 FF FC F8 0 0 0 0 0 0 0 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 3 0 0 FC F8 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FC FE F8 0 0 0 0 0 0 FE 0 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 0 F0 1C 
0 0 0 0 0 0 FE FE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FF E0 0 0 0 0 0 0 0 F8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 F8 FC 0 0 0 0 0 0 0 FF FE F8 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 FE F0 0 0 0 0 0 0 0 0 FE FC F0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 FE FF 0 0 0 0 0 0 0 0 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 C0 F 0 0 0 0 0 0 0 0 F0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 F8 0 0 E0 0 0 0 0 0 0 0 0 FF 0 E0 F8 0 0 0 0 0 0 FF 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 FF FC FC 0 0 0 0 0 FC 0 0 0 0 0 0 0 F0 0 0 E0 0 0 0 0 0 0 0 0 0 0 FE E0 0 0 0 0 FC 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FF 0 0 F8 0 0 0 0 0 0 FC E 0 0 0 0 0 0 0 0 0 0 FF E0 0 0 0 0 0 FF 0 F8 FF 0 
0 0 0 0 0 F8 0 0 0 0 0 0 0 0 0 0 0 FF 0 F0 F0 1C 0 0 0 0 0 0 FF FC 0 0 FE 0 0 0 0 FF 0 FE 0 0 0 0 0 0 0 0 0 0 0 FE FC 0 0 0 0 0 0 0 FE 0 0 0 0 3 F8 0 0 FC 0 0 0 0 0 0 0 0 0 FC FC C0 FE 0 0 0 0 0 0 0 FC FF 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 FE E0 0 0 0 0 0 0 0 0 FC F0 E 0 0 0 0 0 0 FC FE 0 0 0 0 0 0 0 0 0 0 0 FE F0 0 0 0 0 0 0 FF 0 0 FC 0 0 0 F8 0 0 F8 0 0 0 0 0 0 0 0 0 0 0 F8 F0 0 0 0 0 0 0 0 0 0 F8 FE 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 FC 0 0 B8 0 0 0 
0 0 0 0 7 0 FC FC 1C 0 0 0 0 F0 0 0 0 0 0 0 0 0 0 0 E0 0 0 0 0 0 0 0 0 0 0 FC FC 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 E0 FE 0 0 0 0 0 0 0 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 0 0 FF F0 0 0 0 0 0 0 0 FF 0 0 
0 0 0 0 40 0 0 0 0 0 0 0 0 0 0 0 0 FF FC F8 0 0 0 0 0 0 FE F8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FE FE 3 38 0 0 0 0 0 0 FE 0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 7 0 0 0 FC 80 0 0 0 0 0 0 0 F0 0 0 0 0 0 FF 0 0 0 0 0 0 0 0 0 0 
FC 0 F8 F0 0 0 0 0 0 0 0 0 FE F0 0 0 0 0 0 FE 0 0 1C E0 0 0 FC FC 0 F8 0 0 0 0 0 0 0 0 0 FC 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FE 0 0 E0 0 0 FC FF 1C 60 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Mixer turned off

E0 0 FC 0 0 0 0 0 FC 0 0 0 0 FC E0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FC E0 0 0 0 0 0 0 0 FC 0 0 0 0 E0 E0 0 0 0 0 0 0 0 0 0 0 E0 0 0 0 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 1C 0 0 0 0 0 0 0 0 FC 0 0 0 0 
0 0 0 0 0 0 0 0 E0 0 0 0 0 0 0 0 0 0 0 FC 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 E0 E0 0 0 0 0 0 0 3 C 0 FC FC FC 0 0 0 0 0 0 0 0 0 0 1C 0 0 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 0 0 0 FC FC 0 0 FC 7C E0 0 0 
0 0 0 0 0 0 FC FC 0 0 0 0 0 0 0 0 0 0 0 0 1C 0 0 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 1C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FC 3 F8 1C 0 0 0 0 0 0 0 0 0 7F 0 0 0 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 1C 0 0 0 0 FC 0 0 0 0 0 0 0

output slows

0 FC 0 1C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 E0 0 0 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 E0 0 0 0 0 1C 0 0 0 0 0 0 0 0 FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 1C 0 0 0 0 FE 0 0 0

arduino turned off