I want to use FT230XS IC to translate UART to USB, as a cheaper alternative to FT232RL, which I use for years now.
The MCU I use is an Atmega328p-au (so the same configuration as an arduino), and I also have an USB isolator between the PC and the rest of the PCB, like this:
What works: Every time I re-plug the USB or reset the com port the MCU resets, and I can transmit and receive data from the MCU.
What does not work: The issue is, when I try to burn code using the bootloader (either by using Arduino IDE or Microchip Studio), it says "out of sync". BUT, I can see the RTS line resetting as normal via the oscilloscope when I initiate a bootloader burn. So it actually resets, but not fast/slow enough?
Here is the "out of sync" error using AVRdude:
I can see that the MCU is responding, so it actually tries, but its really out of sync. I also see on the oscilloscope, the RTS pin resets the MCU as it should be:
I tried Inverting the pins: RTS,CTS,DTR,DSR,DCD,RI (one at the time) but no luck:
Also a picture of the PCB while probing it with the oscilloscope:
So I suspect that there is something wrong either with the connection between FT230XS and MCU (Like I should use the CTS pin), or a sync error that can be caused by longer wire from PC to the PCB, (but I used a short wire and didn't help), or the USB Isolator might delaying the signal(?).
This is the first time I use the FT230XS. Has anyone use it before and managed to upload a bootloader to any MCU (preferrably an atmega)? If yes, what was the connection between the FT230XS an the MCU?