Hi @chis. Those who have previous encountered problems getting serial data from the native USB boards like Nano ESP32 in external applications reported they found it was caused by a difference in how the application manages the serial control signals (e.g., DTR) compared to the working Serial Monitor. For example:
The solution was more simple for them because they could adjust the code of their application to assert the signal correctly, but since this is a closed source application that won't be possible.
I can suggest an experiment that might serve to test my hypothesis:
- Close all Excel windows.
- Select the port of your Nano ESP32 from Arduino IDE's Tools > Port menu.
- If it is not already open, select Tools > Serial Monitor to open Serial Monitor.
- Close Serial Monitor by clicking the X icon on its tab:
- Start Excel
Now check to see if you see the data being received in the Excel spreadsheet.
The idea is that maybe opening Serial Monitor is sufficient to persistently initialize the serial port of the Nano ESP32, and that after Serial Monitor has performed that initialization, the port will work as expected when it is reopened by Excel.
I don't have Excel installed on my computer so I can't check to see if this works, but it is worth a try at least.