@AdrianMaire Cngratualations to your successfully completing the NE555 PCB and upshift and Full Duplex to Half Duplex cct. On my side and I tidying up my three not that working properly boards: (1) TXS0104 proved not reliable, (2) HC04 + CD4050 initial test OK, but I am not keen to carry on testing, because the wiring of HC04 and CD4050 is messy, and I am only using 1/6 of the the CD4050 IC,
(3) HC04 only is problematic, because I am feeding 5V input to one of the returning HC04 inverter gates. The inverter gates cause double wiring effort, and the pull up resistors are messy to wire in the bread board. In short all 3 prototypes are not acceptable. That is the reason that I am hoping the FeeTech TTLink Mini works reliably , though I still need to use an logical level up shifter.
Then I found a simple TXS0104 upshifter not reliable, so I am stuck here and stall the project for a while. I am also thinking of getting a Wave Share Cortex M3 board which is compatible to Arduino. Then I can use this board to test out FeeTech Arduino library. In the loner term, I can also test out C++ based FeeTech servo programs on this WaveShare M3 board, and then shift down the programs to M0. But I think it might take some time. Ah jogging time. See you later.
@AdrianMaire Yes, I think it should be a good idea that you give the answer to you own question here in EESE or SO. I am not keen to complete my stalled HiWonder answer here, because (1) My three circuit designs still have faults, (2) I have already made up my mind to switch to FeeTech and would pay very little attention in HiWonder. Cheers.
Just as a note: usually C++ is complex/problematic to use in bar-metal software embedded: The main issue is with the unwinding of exceptions, but also with the size of STL library. I suggest you plain-C or some reduced C++ without exceptions (noexcept) for MCU programming. Maybe you know this already, but just in case, so you don't spend too much time on troubleshooting this.
@AdrianMaire Your new answer is very good. So I upvoted. Look back at my incomplete answer, I think that it is out of date, and the TXS0204 based solution is misleading, because it is not reliable. Perhaps I should update my answer with a note, saying why my suggestion is not working, with some explanations, and also why I am switching to FeeTech (but my test on FeeTech is not complete yet, so it might take "some" time. :)
@AdrianMaire Ah yes, I know Cortex M3 C++ might have a very steep learning curve for me. But using C only without OOP is boring. There are some other reasons I would tell you later. First, let me introduce what I am going to order.
Discussion between tlfong01 and Adria…
Discussion between tlfong01 and Adria…