FTDI struggles to transfer above 38400baud?

[Bambo]

Hi, just trying to output a sine wave to a serial montior via an USART-USB FTDI device. When i put the baud rate higher than 38400 baud, the output becomes laggy? Does anyone know why this is?

[Beuzekom]

Are you using HardwareSerial?

[fpiSTM]

Which board? which board? Sketch? ...

[mrburnette]

Hi, just trying to output a sine wave to a serial montior via an USART-USB FTDI device. When i put the baud rate higher than 38400 baud, the output becomes laggy? Does anyone know why this is?

Oh, my... it could be your
- USB cable
- faux chip
- USB host driver
- Host OS
- sine wave (software?) code

... and more.

Put things in prospective and loop-back the "ftdi" device, do some round-robbing tests on the host PC.
Then, try another PC and another cable.

You may need to buy a quality module + cable combination which I often recommend:
https://www.adafruit.com/product/954

[ag123]

uart is just that async, but throughput can go pretty high. for usb-serial i've occasionally seen throughput > 1 mbps, but it does not necessarily mean always 1 mbps constant. and usb does polling, bandwidth is shared by all the devices that the host need to poll
https://www.beyondlogic.org/usbnutshell/usb1.shtml