Unfortunately BPi-R4 doesn’t have a USB to serial interface integrated.
Now I’m using a MAX3232 powered from the board at 3.3V and using an external RS232 to USB cable.
Because of this I’m trying to hack a little bit my BPI-R4 and add a USB to serial IC, like CP2104, inside the case with an USB-C female connector to one of the holes in case:
I want to power this chip from USB-C cable and not to use any additional cabling on BPI-R4, because I don’t have a power pin for UART0. In this way the chip will be turned off when I don’t use serial port.
My pl2303 (067b:2303 Prolific Technology, Inc. PL2303 Serial Port / Mobile Phone Data Cable) adapter with one RS232 was worked ok with MT7988 until yesterday or 2 days ago when Debian upgraded the kernel to 6.9.7. After upgrade is working for few minutes and then is not receiving anything.
My FTDI adapters (0403:6010 Future Technology Devices International, Ltd FT2232C/D/H Dual UART/FIFO IC) is working fine. Is a dual RS232.
My adapter from Odroid XU4 with CP210x (10c4:ea60 Silicon Labs CP210x UART Bridge) is not working. This one is using 1.5V for power and also for RX/TX. I believe this is and issue.
1 and 2 I have to use MAX3232 to convert TTL to RS232 using 3.3V power from board.
I’ve ordered a CP2104 on 3.3V and I will test it. Is working at 3.3V and is powered from USB bus. So I will solder an USB-C PCB+Connector to the hole and trace some cables to this adapter. To the board I will connect only 3 cables: RX, TX and GND.
@Lorem_amicus the one with glavanic isolated sides is pretty overkill. Is pretty big as dimensions.
I don’t have too many events with short-circuits, so I will go on simple path , but for others can be a solution.
Suggest ft232rl module, always works well with different hardware. If you want isolation use a lot of electrical tape or cover the entire module with hot glue from gun.
maybe a feature request for one of the next versions of the board: serial-usb-adapter integrated. i loved that on my old clearfog. using a mini usb cable. nothing to worry about power supply (3.3 vs 5), correct pin layout (rx/tx) etc.
I’m not a fan of Silabs. If it is not working, I will looking for something else!
Big THANKS @frank-w for the link:
I now read it. If I understand the problem right, this is caused by hardware in combination with adapter firmware.
I’m a bit surpriced of the problem, because I use my R3 (Version 1.1) longer than a year and I have setting up all things including wifi with no problem. This is why I decided for Voltlink Rev E board … I will watch out for the problem!
@ericwoud:
Your tonge is a sharp knife! But your commant causes some fun, after my brain trieded to find an answer for the question how I can use a USB to UART adapter after I covered the whole thing with electrical tape.
Next step is to unsolder USB-A connector + DUPPON connectors from PCB, add USB-C with a cable from the whole till the PCB, fix the PCB somewhere in the case and that’s it.
For who is interested I finished the adapter USB-C to RS232 for BPI-R4. It doesn’t have the best nice looking holding of the USB-C connector, but is doing its job. I’m not going with it to any presentations
something like that would be nice to have by default on the board + with default case. wondering if there is some sort of feature requests for the next rev’s