Stopping the MPPT 75 I 15 from sending asynchronous data

Modifications
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1

Hi,

I have connected and ESP32 to an MPPT7515 and need to stop the asynchronous messages that are sent. I have tried setting the TX Port operation mode (register 0xED9E) but this seems to stay at 0 regardless of the value I attempt to write!.

The main reason I would like to stop the asynchronous messages is that when I send messages to toggle the load they do not always work and I need to resend. I am assuming that the MPPT is not capable of processing received messages whilst in the middle of transmitting.

Has anyone else had problems sending messages to an MPPT?

2

Why don’t you change the behavior of tx with victronconnect ?

Set it to pulse output or virtual load and it will surely stop transmitting

3

My intention is to monitor and control the MPPT using an ESP32 microcontroller. The documentation does indeed state that the way to stop the asynchronous messages is to set the tx behaviour by writing a no-zero value to register 0xED9E, however this does not appear to work!

4

Well, then why not try victronconnect?

Is this a smartsolar ?

Then maybe you should try to disable the bt broadcast function as well.

5

Hi @IanJames

The MPPT is perfectly capable of receiving a message while transmitting async messages or the text frame. When you send a VE.Direct Hex message, you do have to wait for an answer before sending a new command. When an answer is not received within a second, the command can be retried.

Kind regards,
Thiemo van Engelen

6

Hi Thiemo,

Thanks for your advice, I have modified my code to wait for a response before sending a new request, which works well.

The product is an MPPT 75 I 15

Reading the product code I get A042
The appVersion returns 4159 i.e. version 1.59

Requesting the panel voltage(edbb) :7BBED00A6

I get the response: 07 bb ed 00 5c 0a

0a5c hex → 2652 decimal i.e. 26.52v

When I request the following registers I fail to get a response

Model name(010b) :70B010042

Serial number(010a) :70A010043
Daily history(1050) :7501000EE
Total history(104f) :74F1000EF

Any thoughts?

Kind regards,

Ian James

7

Hi @IanJames

These should always lead to a proper response. Can you post a full log of the serial communication?

Regards,
Thiemo van Engelen

8

Hi Thiemo,

Following is a log of the data bytes sent and received, I have shown examples of the register requests that work.
At the end of the log you will see the requests for the daily history none of which provide a response from the MPPT.

The firmware has been updated to the latest version using the VictronConnect app on a PC

Kind regards,

Ian James
Binary Electronics Limited

Terminal log file

9

Hi Thiemo,

I have solved the problem!

I am using a third party VEDirect library and I have found that the maximum receive buffer was set to 32 bytes which is insufficient for receiving log data!

Apologies for wasting your time.

Kind regards,

Ian James
Binary Electronics Limited

10

Hi @IanJames

Good to hear that everything is working now.

Kind regards,
Thiemo van Engelen