Flowcode Support Board

Hello everybody

I have a question about serial communication (com port)

I am currently using esp32 devkit to build a small test station. The program is very simple and is based on sending and receiving data from the esp32.

The problem arises when I have to send and receive LONG or FLOAT data. If I send a single data (such as the reading of an adc) I have no problems, but if I want to send more then I get lost.

For example in the attached program I try to send 3 float values ​​consecutively from the esp32 card and these values ​​must be saved in the program. files are not saved or data does not arrive.


Another thing I noticed that when I send the data from the PC, in the console are sent doubles (only when I send the floats or number). This does not happen if I send a single byte

I would like to understand if it is a timing issue or the way I send and receive data is wrong.

Hello,

You could solve this one of two ways.

1) After transmitting each float transmit a ',' character or something else none numeric ( '0' - '9' ) so the routine to receive the float has a delimiter to know when one value ends and the next begins. You might also need a delay after sending each comma to allow the conversion of the ASCII string back into a float format to avoid flooding the MCU UART receive buffer (not likely on the ESP hardware but very likely on something like a PIC/AVR).

2) Instead of using the SendFloat and ReceiveFloat functions you could use the SendBinaryFloat and ReceiveBinaryFloat as this has a fixed with of 4 bytes and so no delimiter character would be required. It won't be readable in the console / terminal emulator but it will be more efficient in terms of less bytes being transmitted and less numeric manipulation to get to and from the float variable.

Hope this helps

Hi Ben

I try to implement the recommendations and let you know!

Edit

With the first solution I was lucky and by inserting a character I can send floats in sequence.

Unfortunately not with the second solution.

In the next few days I will try to understand why it doesn't work