I am using the FTDI FT4232H Mini Module so I can do USB-UART and upgrade the firmware of SIM808 via the UART interface because the breakout board (schematic attached) I have does not support USB directly.
I am using Channel C of FT4232H Mini Module TX & RX to communicate to RX & TX of Sim808 respectively.
I followed all your instructions from the blog and the video (making sure about the baud rate etc.), and still my process get stuck in “0%(waiting)” despite when I turn on the PWR_KEY. Also from the forum, it seemed that no one has had this issue. Maybe it’s something trivial that I am missing…
I tried both 1.10 and 1.19 V of the firmware tool. I also made sure the appropriate VCP drivers were installed on my machine.
I tried Channel C and Channel D and still the same issue.
I would greatly appreciate any input on this issue. Thank you!