MPPT Bluetooth read out

Modifications
,
1

Hi all,
I do a readout of the bluetooth data and this is working well.
Now I bought another MPPT 75/15 Solar Charger.
This new readout data is totally rubish and makes no sense.

My question - is there any know problem from one MPPT to another MPPT? Both are the same and on the same firmware and working via Victron app without any problem. Just wondering…
Best
Sascha

2

Post a screenshot?
Cant comment on what we cannot see.
Usually i don’t have an issue.

3

@lxonline
a bit tricky but lets try.

The one which is working I get the raw decrypted data
02E1100253A001175D930500A40500000B00000000FE00

the part which is interesting
0500A40500000B00000000FE

image
image840×668 17.2 KB

The not working one
02E1100253A0013189D47B150DD0D7D0F1EA92224A5B00000000000000000000

image
image854×671 18.8 KB

Both are model A053 - MPPT 75-15

Hope this helps
Thanks

4

Moved to Modifications section as direct readout is not a standard use case.

1 Like
5

Hi @Saschakopp

Are you using the correct encryption key for the non-working MPPT? Every device has its own encryption key, which also changes when you change the pincode.

With kind regards,
Thiemo van Engelen

6

@thiemovanengelen
I copied the readout information from the Victron app. If the key is not correct the code woudn’t work as all.

7

@Saschakopp

If the key is not correct you would typically get weird values as you are experiencing as there is no check using a hash or CRC or something to check whether the result of the decoding is sane. The only check that can be done is is the first byte of the encryption key that is also in the manufacturer data.

With kind regards,
Thiemo van Engelen

8

@thiemovanengelen I will change the pin to another one and change it back to see if this would fix the problem - will keep you posted
Thanks for your help

9

@Saschakopp

Every time that the pincode is changed, it sets the key to a random value. So changing the pincode to some new value and then changing it back to the previous value does not give you the same encryption key as it had previously! So every time the pincode is changed, the encryption key has to be copied from VictronConnect again.

Kind regards,
Thiemo van Engelen