I am trying to use ADXL345 to test for vibration in a machine. My colleague advised we try to achieve higher samples since we are going to connect ESP-01 and use ESPnow protocol
If you want higher-frequency data, you need a different sensor. The link below is an article from Analog Devices on choosing a MEMS vibration sensor. There is a chart that shows their highest-bandwidth sensors are in the 25 kHz range. If you google "high-frequency MEMS vibration sensor", you will find many links and articles.
https://www.analog.com/en/technical-articles/best-mems-sensor-for-wireless-cbm-system-part-2.html
Okay thanks, do you have an idea of the maximum possible ksps we can achieve