Blynk Terminal max number of lines when reading from SD card

Hello everyone,

I would like to know what is the maximum number of lines that I can send from hardware side (example reading from SD card) and print on terminal? I am testing right now with more than 25 lines and it is working well, but I am afraid when trying with more lines if it could make my hardware to get disconnected from Blynk?

Reason of this test is to increase the history size on terminal (bigger than 25 lines) so I am storing the data on SD card.

I dont know if this is relevant but I am using the Wemos D1 mini + microSD card adapter.

Thank you.

Additionally I am using the while function so it will read everything from file before continue with loop:

while (file.available()) {         // read from the file until there's nothing else in it:

There is no limit that I’m aware of, just the limit of how quickly the data can be written to the server without causing issues - 10 writes per second for the cloud server.

You’ve previously asked questions about a local server setup, but you’ve not said here whether your’e using a local or cloud server.
If it’s local then you can increase terminal.strings.pool.sizeto overcome the 25 message (not line) limit.


Displays data from your hardware. Allows to send any string to your hardware. Terminal always stores last 25 messages your hardware had send to Blynk Cloud. This limit may be increased on Local Server with terminal.strings.pool.size property.

Is this serial output that you’re sending to the server? If so then there’s a much easier solution.

If not then have you considered a table, which will hold the last 100 lines?


Hello Pete, thank you for the fast answer.

I am using the cloud server and not I haven’t considered the table. I am developing a data logger that will not store values but date, time and action, so it is a big line example:

4/6/2020 13:45:56 Received: 127147301 bits: 28 Protocol: 6
4/6/2020 13:46:12 Received: 127147301 bits: 28 Protocol: 6
4/6/2020 13:46:13 Received: 127147285 bits: 28 Protocol: 6

So image a text file with hundreds of lines similar to the ones above. I think the table is not suitable for this application? Maybe terminal is better for my case?

You might be able to squeeze the data into a table, if you dumped the “received, bits, protocol” text and used used the time/date and data elements only.
But, as I said it’s limited to 100 rows.

This looks like 433Mhz data and if that’s the case then the data might be more readable if the codes were translated into meaningful names. If you’re looking to capture unrecognised codes then obviously a different approach might be needed.


Hello Pete,

Exactly those are 433Mhz data, and yes I will translate the codes by names, example (Door living room, Window garage, etc). I have done a test with table and the text size is big, so the complete text with date and time is not readable as well as the sensor name.

So I decided to continue with the Terminal because it shows the complete text and this lets the opportunity of giving a bigger name for each sensor.

Maybe if the reading process from SD card and print to Terminal gives me trouble with connection to Blynk I will just disable this and just remove the SD card and read on laptop, I wanted to avoid this but I dont think I have other option.

Thank you.