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FTDI struggles to transfer above 38400baud?
Posted: Wed Feb 10, 2021 11:53 am
by 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?
Re: FTDI struggles to transfer above 38400baud?
Posted: Wed Feb 10, 2021 3:45 pm
by Beuzekom
Are you using HardwareSerial?
Re: FTDI struggles to transfer above 38400baud?
Posted: Wed Feb 10, 2021 3:53 pm
by fpiSTM
Which board? which board? Sketch? ...
Re: FTDI struggles to transfer above 38400baud?
Posted: Wed Feb 10, 2021 5:47 pm
by mrburnette
Bambo wrote: ↑Wed Feb 10, 2021 11:53 am
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
Re: FTDI struggles to transfer above 38400baud?
Posted: Thu Feb 11, 2021 8:18 am
by 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