Decrypting the Vado Identity wired shower controller

Projects & Topics Device Hacking
#23

Bit more messing with the controller...

If I press the power button, there's a bit of mess where it looks like the controller stops talking for a few packets while the mixer sends the following:

00 00 00 00 00 00 16

The controller then talks over the mixer for a couple of packets until it settles into the following:

00 00 00 00 00 00 16   12 72 01 16 07 02 00

After that I pressed the button to switch to a different shower outlet at which point there was some mess again followed by:

00 00 00 00 00 00 16   12 72 01 16 07 01 00

They then settled into the following:

00 00 00 00 00 00 16   11 72 01 16 07 01 00

I then hit the pause button, there was mess, then:

00 00 00 00 00 00 16   12 7A 02 16 07 01 00
00 00 00 00 00 00 53   12 72 02 16 07 01 00

I think the first line above may be a read error and 7A should in fact be 72

Then they settle into the following:

00 00 00 00 00 00 16   12 72 02 16 07 01 00
00 00 00 00 00 00 53   12 72 02 16 07 01 00

At some point thereafter they settle into the following:

00 00 00 00 00 00 16   12 72 02 16 07 01 00
00 00 00 00 00 00 51   12 72 02 16 07 01 00
#24

New update!

I'm sort of talking to the controller. Certainly it knows I'm talking and is responding.

I rewrote the code to replicate the 3 stage start up sequence (from post 21) and then connected the controller to the arduino and it seems to be responding. As far as the data being received from the controller in response to the data I'm sending, it looks identical to what's received when it's connected to the arduino.

The only difference in the data, and the main issue I seem to be having, is that on one of the 2 rs485 data pins the idle is HIGH whereas on the mixer it's LOW (see attached).

I'd like to resolve the data issue in order to eliminate it from the investigation (plus I think the arduino's signal is wrong as per the rs485 spec / requirements / guidelines / whatever).

Aside from the data issue I've found that when I connect the controller to the arduino and power everything on, the screen stays on the "00", the backlight stays lit and the buttons are unresponsive. However, if I start everything up and then move the controller connections to the mixer (which is powered on patiently waiting) the backlight then goes out which is the appropriate standby mode and the buttons are responsive. Better yet, if I then move the connections back to the arduino, the buttons remain responsive. I can perform all of the usual actions on the buttons until I attempt to put it back into standby at which point the buttons then become unresponsive once more.

Clearly the unresponsive buttons is a blocker for real use but I may continue to work on the code that handles the state, temp, pressure, etc. until I have a breakthrough or somebody points out the glaringly obvious mistake to me...

arduino_vs_mixer.png|1305x700

#25

What RS485 module are you using and does it have the relevant/correct pullup/pulldown resistors on the A/B lines and maybe the 120 ohm terminator?

#26

Riva: What RS485 module are you using and does it have the relevant/correct pullup/pulldown resistors on the A/B lines and maybe the 120 ohm terminator?

It's this one: https://www.amazon.co.uk/WINGONEER-MAX485-Module-RS-485-Development/dp/B06XHHWLMW

From the looks of the schematic it's got all the resistors and the board seems to match the schematic (in terms or the number of components).

My first thought was pull up / down resistors so I tried adding a couple of 220's in parallel (so 110 ohm) across the A / B and from each as pull up / down but all I managed to do was change the "incorrect" pin to the other one. So it feels like it's in the right region but I'm not really sure how to work out what's required.

The next thing I'm going to try is to measure the resistance across everything with the controller connected to the mixer and then again with the controller connected to the arduino, both with everything powered on and off. At least that will tell me what the difference is between the 2 scenarios...

#27

If you disconnect the mixer and just connect your logic analyser to A, B & Gnd of the MAX485 module while sending data, does it then show idle as low or still as high?

#28

Riva: If you disconnect the mixer and just connect your logic analyser to A, B & Gnd of the MAX485 module while sending data, does it then show idle as low or still as high?

Exactly the same. Still HIGH.

#29

Monkey3: Exactly the same. Still HIGH.

Is the MAX485 module in RX or TX mode when you take the readings?

EDIT: Using the simple test program below on a Mega

#define DE 2
#define RE 3
#define TEST 4
#define DELAY 100

void setup()
{
  Serial.begin(115200);
  Serial1.begin(9600);
  pinMode(DE, OUTPUT);
  pinMode(RE, OUTPUT);
  pinMode(TEST, OUTPUT);
  Serial.println("Setup End");
}

void loop()
{
  Serial.println("DE/RE High");
  digitalWrite(DE, HIGH);
  digitalWrite(RE, HIGH);
  digitalWrite(TEST, HIGH);
  delay(10);
  Serial1.print("Hello World");
  delay(DELAY);
  Serial.println("DE/RE Low");
  digitalWrite(DE, LOW);
  digitalWrite(RE, LOW);
  digitalWrite(TEST, LOW);
  delay(DELAY);
}

I get the below image on my LA. You need to put the MAX481 into receive mode to release the lines.

|500x260

Clipboard-1.jpg|1528x797

#30

Riva: Is the MAX485 module in RX or TX mode when you take the readings?

EDIT: Using the simple test program below on a Mega

...

I get the below image on my LA. You need to put the MAX481 into receive mode to release the lines.

...

Using the same code I get the attached.

riva-test.png|1287x213

#31

Monkey3: Using the same code I get the attached.

That's strange, when TEST is low the MAX chip should be in receive mode and the pullup resistor should hold the A line high (on my image it is low but this is probably the logic probe pulling it down) and the pulldown holds the B line low. On your trace A is behaving as expected but B is remaining high.

I used a module that looks like yours but I don't have it with me to check the exact model and MAX chip used. I'm at work and just happen to have a MAX485 chip (not module) to hand to connected it to using the same scheme and get the same results. |500x50 Maybe you should try another MAX485 module/chip.

Clipboard-1.png|1450x147

#32

I've tried a second and third module and it's exactly the same (see attached) - although all the modules came in the same pack so that may be saying too much.

The chip is MAX485 ESA +18DN if that makes any difference.

When I look at your image versus mine, they look exactly the same but the mirror image. With the exception that the test channel is not the mirror image.

I really don't know what that means.

I'm looking to see if there's another, different module I can get quickly and cheaply for comparison...

new-rs485-riva.png|907x276

#33

AFAIK the 3 characters after MAX485 denote the package type. ESA is 8 pin SO package. When your testing you only have them connected to the logic analyser? The Amazon link you posted has a schematic image so maybe check module matches schematic with a continuity meter Maybe the whole packet of MAX485 modules are faulty or poorly designed/built or it could just be your logic device pulls the lines high when they are floating and mine pulls them low.

#34

Riva: AFAIK the 3 characters after MAX485 denote the package type. ESA is 8 pin SO package. When your testing you only have them connected to the logic analyser? The Amazon link you posted has a schematic image so maybe check module matches schematic with a continuity meter Maybe the whole packet of MAX485 modules are faulty or poorly designed/built or it could just be your logic device pulls the lines high when they are floating and mine pulls them low.

When testing, I've tried a couple of different combinations and they all give the same result.

| CHANNEL | CONNECTED | SIGNAL AT IDLE | | - | - | - | | A | arduino and logic analyser | high | | A | arduino, controller and logic analyser | high | | A | mixer and logic analyser | low | | A | mixer, controller and logic analyser | low |

So I've ordered another, very different rs485 (https://www.amazon.co.uk/gp/product/B07B667STP) which should be turning up tomorrow so, with any luck, this will resolve the issue.

#35

OK, I think this is good news.

The new module doesn't have DE / RE pins, rather it relies on the TX to tell it when to switch to send / receive mode.

It does seem to properly switch back to idle though. :D

ALSO... After some head bashing / panicking it would appear that actually the controller is working at 9600 baud with an ODD parity bit and I'm now able to immediately add a UART decoder with no frame errors!!!

It does mean that I now need to go back and re-analyse the mixer / controller traffic but that should be fairly easy.

Watch this space...

#36

Glad you have one problem sorted and found the next hurdle to jump. Just to put the old RS485 modules problem to bed how was you connecting them up?

#37

Riva: Glad you have one problem sorted and found the next hurdle to jump. Just to put the old RS485 modules problem to bed how was you connecting them up?

For the old modules I connected them the same way described here.

Essentially:

| Arduino | RS 485 | | - | - | | TX | DI | | RX | RO | | 3 (Direction Control) | DE / RE | | GND | GND | | 5V | VCC |

I don't know whether I got a bad batch or what but I must've re-wired the circuit about 50 times to make sure it was together correctly. So gawd knows.

#38

Ok, so with the new RS 485 module, I'm wired back in to try to work out the sequences again and here goes...

Any lines followed by "x n" means that the lines above (until the previos blank line) are repeated n times "x ..." means the lines are repeated an unknown number of times or indefinitely

Just the mixer connected

00 00 00 00 00 00 00
x ...

Connect the controller This just shows the handshake and then the mixer's start up sequence

00 00 00 00 00 00 00  00 00 00 00 00 02 00

00 00 00 00 00 00 41  33 F2 02 36 07 02 00
00 00 00 00 00 00 B3  33 F2 02 36 07 02 00
00 00 00 00 00 00 41  33 F2 02 36 07 02 00
00 00 00 00 00 00 B3  33 F2 02 36 07 02 00
00 00 00 00 00 00 41  33 F2 02 36 07 02 00
00 00 00 00 00 00 B3  33 F2 02 36 07 02 00

00 00 00 00 00 00 1D  33 F2 02 36 07 02 00
00 00 00 00 00 00 B3  33 F2 02 36 07 02 00
x 55

00 00 00 00 00 00 1D  33 F2 02 36 07 02 00
00 00 00 00 00 00 B1  33 F2 02 36 07 02 00
x ...

Turn shower on

00 00 00 00 00 00 B1
00 00 00 00 00 00 B1
00 00 00 00 00 00 B1
//MESS
00 00 00 00 00 00 B1  32 F2 01 36 07 02 00
00 00 00 00 00 00 1D  32 F2 01 36 07 02 00

00 00 00 00 00 00 1D  32 F2 01 36 07 02 00
x ...

Turn shower off

00 00 00 00 00 00 1D
00 00 00 00 00 00 1D
00 00 00 00 00 00 1D
//MESS
00 00 00 00 00 00 1D  33 F2 02 36 07 02 00

00 00 00 00 00 00 1D  33 F2 02 36 07 02 00
00 00 00 00 00 00 B1  33 F2 02 36 07 02 00
x ...

Turn shower on then Change to outlet 2

00 00 00 00 00 00 1D
00 00 00 00 00 00 1D
00 00 00 00 00 00 1D
MESS
00 00 00 00 00 00 1D  31 F2 01 36 07 01 00
x ...

Turn shower off

00 00 00 00 00 00 1D
00 00 00 00 00 00 1D
00 00 00 00 00 00 1D
MESS
00 00 00 00 00 00 1D  32 F2 02 36 07 01 00

00 00 00 00 00 00 1D  32 F2 02 36 07 01 00
00 00 00 00 00 00 B3  32 F2 02 36 07 01 00
x...

00 00 00 00 00 00 1D  32 F2 02 36 07 01 00
00 00 00 00 00 00 B1  32 F2 02 36 07 01 00
x...

Turn shower on then Increase flow

//Min flow
00 00 00 00 00 00 1D  32 F2 01 36 05 02 00

//Low flow
00 00 00 00 00 00 1D  32 F2 01 36 06 02 00

//Med flow
00 00 00 00 00 00 1D  32 F2 01 36 07 02 00

//High flow
00 00 00 00 00 00 1D  32 F2 01 36 08 02 00

//Max flow
00 00 00 00 00 00 1D  32 F2 01 36 09 02 00
#39

There was some unexpected behaviour from the mixer while all that testing was going on. At some point I noticed that the last bit from the mixer started to rise. I assume that this indicates the temperature that the water flowing through the mixer has reached but even after I turned the mixer off it continued to rise for a bit, possibly down to heat soak.

Mixer behaviour

...
00 00 00 00 00 00 23

00 00 00 00 00 00 24
x 5

00 00 00 00 00 00 25
x 7

00 00 00 00 00 00 26
x 17

00 00 00 00 00 00 27
x 11

00 00 00 00 00 00 28
x 18

00 00 00 00 00 00 29
x 6

00 00 00 00 00 00 2A
x 5

00 00 00 00 00 00 2B
x 6

00 00 00 00 00 00 2C
x 24

00 00 00 00 00 00 2D
x 11

00 00 00 00 00 00 2E
x 6

//turn off

00 00 00 00 00 00 B3
00 00 00 00 00 00 2E
x 3
00 00 00 00 00 00 B3
00 00 00 00 00 00 2F
x 4
00 00 00 00 00 00 B3
00 00 00 00 00 00 30

I'm going to test a bit further to see if the mixer's temp matches up to the temp from the controller...

Then, bizarrely, the controller's first bit changed as well. I'm yet to work out what the controller's first bit is for...

Controller strangeness

35 F2 02 36 09 02 00
#40

ARRRRRGGGGGHHHHHH!!!!!!!

:( >:( >:(

It seems the new rs485 doesn't want to read all of the data.

the following code:

//Transmission config
long baudRate = 9600;
byte serialConfig = SERIAL_8O1;
//Transmission Details
/////////////////////////////////////////////////////////////////


/////////////////////////////////////////////////////////////////
//Timing
long unsigned lastCom = 0;
long unsigned curMicros = 0;
const unsigned long comPeriod = 55240; //should 55240 - 55280 - Arduino is not perfect at timing so 55240 seems to equate to roughly 55260
//Timing
/////////////////////////////////////////////////////////////////


/////////////////////////////////////////////////////////////////
//Message Length
const int MSG_LEN = 7;
/////////////////////////////////////////////////////////////////


/////////////////////////////////////////////////////////////////
//Outgoing message details
//Outgoing messages
const byte MSG_INTRO[MSG_LEN] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
//Outgoing register
byte message[MSG_LEN];
//Outgoing message details
/////////////////////////////////////////////////////////////////


/////////////////////////////////////////////////////////////////
//Controller message details
//Incoming register
byte receivedData[MSG_LEN];
int nCurByte = 0;
//Controller message details
/////////////////////////////////////////////////////////////////

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

  memcpy(message, MSG_INTRO, MSG_LEN);
}

void loop()
{
  SendData(message);

  if (ReadData()) {
    PrintData();
  }
}

void PrintData() {
  for(int i = 0; i < MSG_LEN; i++)
  {
    Serial.print(receivedData[i], HEX);
    Serial.print(" ");
  }
  Serial.println("");
}

void SendData(byte sendMsg[]) {
  curMicros = micros();
  if ((curMicros > (lastCom + comPeriod)) || (curMicros < lastCom)) {
    lastCom = curMicros;
    Serial1.write(sendMsg, MSG_LEN);
  }
}

bool ReadData() {
  while (Serial1.available() > 0) {
    receivedData[nCurByte++] = Serial1.read();

    if (nCurByte >= MSG_LEN) {
      nCurByte = 0;
      return true;
    }
  }
  return false;
}

Prints:

...
F2 2 7 2 F2 2 7 
2 F2 2 7 2 F2 2 
7 2 F2 2 7 2 F2 
2 7 2 F2 2 7 2 
F2 2 7 2 F2 2 7 
2 F2 2 7 2 F2 2 
F2 2 7 2 F2 2 7 
2 F2 2 7 2 F2 2 
7 2 F2 2 7 2 F2 
2 7 2 F2 2 7 2 
F2 2 7 2 F2 2 7 
2 F2 2 7 2 F2 2 
7 2 F2 2 7 2 F2
...

It's definitely reading the incoming data as I'm expecting: 33 F2 02 36 07 02 00

And the logic analyser is picking up all the data. It's looking like I'm going to need to use the old module to read the incoming data and the new module to write the data. I've tried using ReadBytes but that just times out after about a second or something (whatever the default is).

I'm at a loss...

#41

Minutes later, I'm no longer at a loss...

AND WE'RE OFF!!!!!!!! :D :D :D

It looks like it's using SERIAL_8N2. Certainly, if I set the arduino to use that config then I can read all the data. sigrok seems to think that the controller is using a zero parity type but we don't have that option in arduino. So at 8N2 sigrok shows loads of parity errors from the arduino but it works dagnabbit!

On starting up the arduino with my new code using SERIAL_8N2 the screen is no longer flickering and goes into standby mode.

And I'm now able to properly communicate!!!!

It's been a long time coming and we're not there yet but this is a massive step forward and for the first time I can talk back to the blasted controller. Now I just have to add in the logic but that's the easy bit.

Massive thanks to Riva for keeping me going. ;) ^^^ Starting to sound like an awards ceremony :D

Here is the info I have managed to gather about what the controller is sending:

3rd byte - Power

| Power | 3rd byte | | - | - | | ON | 01 | | OFF | 02 | | PAUSED | 03 |

4th byte - Requested Temperature

| Temp (deg C) | 4th byte | | - | - | | 25 | 29 | | 26 | 2A | | 27 | 2B | | 28 | 2C | | 29 | 2D | | 30 | 2E | | 31 | 2F | | 32 | 30 | | 33 | 31 | | 34 | 32 | | 35 | 33 | | 36 | 34 | | 37 | 35 | | 38 | 36 | | 39 | 37 | | 40 | 38 | | 41 | 39 | | 42 | 3A | | 43 | 3B | | 44 | 3C | | 45 | 3D | | 46 | 3E |

5th byte - Flow Rate

| Flow | 5th byte | | - | - | | MIN | 05 | | LOW | 06 | | MED | 07 | | HIGH | 08 | | MAX | 09 |

6th byte - Outlet

| Outlet | 6th byte | | - | - | | Default | 02 | | Alternate | 01 |

#42

I should have jumped forward to your last message first instead of working my way through them one at a time and then going of reading about the connection example of the RS485 modules and then trying to decode the protocol only to find you have already done it. LOL

Glad your getting consistent and predictable results now and look forward to you posting the project is finished and working as expected. Also glad to help though I don't feel I helped much apart from showing someone was listening. I would like to investigate the old MAX485 modules in more detail as I feel the boards you bought are probably just the same as the rest of them that look the same (like mine) but maybe they have faulty MAX485 chips or some other issue.