Orange Pi 5 USB-TTL Output Garbled Characters

[Shane]

Hi,

Armbian_23.02.2_Orangepi5_jammy_legacy_5.10.110 works well with my OPI5. I can ssh to and play with it from my Debian desktop. I don't have HDMI monitor so I want to try serial port.

i'm using USB-TTL cable to connect OPI5 to my Debian box. 

Then in Debian bash I use this command to connect to the port

screen /dev/ttyUSB0

Then power on the OPI5. The output is garbled:

If i change it to cs7 (screen /dev/ttyUSB0 cs7), the output is still something I cannot understand:

The stty command and output:

$ sudo stty --file=/dev/ttyUSB0 --all
speed 9600 baud; rows 0; columns 0; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff
-iuclc -ixany -imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
echoctl echoke -flusho -extproc

 

I'm sure the USB-TTL cable lines are plugged as expected:

green line to RX, white line to TX, black line to GND. TX/RX/GND are as the offical PIN definition: http://www.orangepi.org/img/pi-5-pin-definition.png

 

Any idea what went wrong?

[Werner]

Set baud rate to 1500000

[Shane]

Hi:

with command: screen /dev/ttyUSB0 1500000

screen /dev/ttyUSB0 1500000,cs7 shows similar garbled output too.

[Werner]

Works nicely for me. No need to adjust any parameter besides baud rate to 1.5Mbaud as it is default to all Rockchip SoCs.

Make sure your adapter can handle this rather high speed.

Also make sure to cross-connect RX/TX.

[Shane]

Thanks. Issue resolved after buying a FT232 USB-TTL cable.

[ArmBoy1988]

Can someone provide a link, on amazon.ca if possible, to a cable that is known to work.

 

I'd like to see what output, if any, is available when my Orange Pi 5 is not booting from NVMe.

 

Thank you

[royk]

@ArmBoy1988 This one should do

https://www.amazon.ca/DSD-TECH-SH-U09F-Adapter-Featuring/dp/B07K76Q2DX/

[ArmBoy1988]

@royk Thanks.  I hadn't considered a type like that one.  I picked up this:

 

https://www.amazon.ca/dp/B0BX232GYG

 

I'm hoping it should work.  Haven't tried yet.  Only thing that I'm not sure about is the baud rate and the voltage.

• Most of these types of items on Amazon don't list the maximum speed so I'm not sure it can handle a 1500000 baud rate.  They also don't mention if one of its presets has that baud rate either.
• Same goes with the voltage.  Most of these don't specify voltage.  Some specify 3.3v and 5v others say one or the other.  I see the one you identified supports both and can switch with a jumper.

Don't know which voltage is needed or if it matters.  The three pins on the OPi5 are ground, TX and RX where the voltage wire is not used.  So, voltage is taken from the device being connected to?  It's used to power the chip the converter cable/chip being used?  If that's the case, that means you can't harm the OPi5, hopefully.  Right?  The one I purchased uses the Pl2303Hx.  I figured the cable I purchased is like all/most of the other cables you see and that they are mostly knock-offs.

 

Any way, I'll be trying it at some point in the near future.  Thanks again.

[royk]

@ArmBoy1988 You'll need one @3.3v there is also voltage on the data pins.

To only read the serial data you only need to connect 2 wires

OPI.    Adapter

Gnd -   gnd

TX    -   RX

 

I don't think that the UART pins are 5v tolerant.

[ArmBoy1988]

It looks like I purchased the wrong one.  I was unaware that it had to be a 3.3v one.  Haven't tried this out yet as there was no need to.  I had purchased it to try to figure out an issue I was having booting up the OPi5 but I got it booting before trying this.

 

Reading the listing for the one I purchased it says under the wire definitions "red +5v".  I'll purchase another one, probably the one you pointed out, that you can set at 3.3v.  

 

Thanks.

[CryBaby]

I think the one you have will be fine. Just don't connect the red wire, even on boards which have 4 pins.

[royk]

@CryBaby Could you explain why? Because when I set my TTL adapter to 5v there is 5v on the rx and tx pins, since you connect at least gnd and tx or rx......

[CryBaby]

I don't know how it works but in my experience it does. The Prolific page here says "Flexible signal level requirement on the RS-232 like serial port side also allows the PL-2303HX to connect directly to 5V, 3.3V, or 2.5V devices."

[ArmBoy1988]

That means the chip supports those voltages.  However, you have to set what voltage to use.  Many of these cables are set for just one of the voltages.  There are modules that allow you to set the voltage using jumpers.  The cable I had purchased only said 5V.  The module that royk linked to had the jumpers so the voltage is selectable.  I did read that if you had a 3.3v cable, it would likely work on a 5v system but I don't think it works the other way around as the 5v would exceed what the 3.3v can handle.

[ArmBoy1988]

Confirmed on the OrangePi site that the TTL is 3.3v here:  http://www.orangepi.org/html/hardWare/computerAndMicrocontrollers/service-and-support/Orange-pi-5.html in the User Manual, v1.5 for the Orange Pi 5.

[royk]

@CryBaby Seems to be true for this specific chip indeed.

Explanation:

https://techblog.willshouse.com/2015/01/07/how-to-tell-if-pl-2303hx-pl-2303-is-3-3v-or-5v/

 

That something works doesn't always mean that it's good, I've seen people connecting 5v to 3.3v pins, (probably something between 4 and 4.5v) and didn't have problems for a few months and eventually it broke.

But you're right about the PL-2303HX.