Re: USB-serial adapter suggestions needed

On Thu, Dec 28, 2023 at 12:38:58PM -0800, Mark Millard wrote:
> On Dec 28, 2023, at 11:24, bob prohaska <[email protected]> wrote:
> 
> > On Wed, Dec 27, 2023 at 12:27:33PM -0800, Mark Millard wrote:
> >> 
> >> Overall I've not been able to understand what the
> >> (various?) hypothesized stage-by-stage byte flow
> >> paths are in these notes.
> >> 
> > 
> > Maybe this will help. The path is
> > 
> > workstation> Ethernet > terminal server:usb-serial > serial wires> GPIO 8/10
> > 
> > I hesitated to use the words "terminal server" because that has implications
> > (distinct IP address, multiple serial interfaces) that don't exist here. 
> > 
> > The workstation is a RasPiOS Pi4, the Pi3 host called pelorus is the terminal
> > server and the GPIO pins are on the Pi3 host named www.zefox.net .
> 
> Your prior messages reported text referencing .org, such as:
> 
> FreeBSD/arm64 (www.zefox.org) (ttyu1)
> 
> and:
> 
> No, the garbled login prompt originates from www.zefox.org's
> serial console.
> 
> and:
> 
> Understood, it's been hard to articulate 8-( Maybe
> Workstation > ethernet > pelorus > usb port > gpio 8,10 > console www.zefox.org
> is a little clearer
> 
> So: "www.zefox.net <http://www.zefox.net/>" above is a change of report, if I understand
> right.
> 

It's my typo 8-( 
The host generating console output is the Pi3 named www.zefox.org .
The host named www.zefox.net isn't involved at all, though it is
present and I typed its name in error.

> > The Ethernet connection works well enough for all the other hosts  that I think 
> > we can disregard whether it's wired or WiFi and LAN or WAN or all four.
> 
> You have also reported that:
> 
> The Pi3 which reported the garbled login prompt 
> uses in config.txt:
> b@www:/boot/msdos % more config.txt
> init_uart_clock=3000000
> enable_uart=1
> kernel=u-boot.bin
> kernel7=u-boot.bin
> dtoverlay=mmc
> force_mac_address=b8:27:eb:71:46:4f
> 
> This is using the mini-uart for the serial console and the
> full-function UART for bluetooth. It also is not using
> arm_64bit=1 . (So armv7 support instead of aarch64 support?)
>

You are correct, it's using the mini-uart (which I didn't realize)
per sysctl.  The machine is running aarch64, the reference to kernel7 
in config.txt is a mistake.  Bluetooth and WiFi aren't used on www.zefox.org. 
 
> https://elinux.org/RPi_Serial_Connection claims:
> 
> QUOTE
> . . . the less capable mini-UART with no break detection, no framing errors
> detection, no parity bit, no receive timeout interrupt and no DCD, DSR,
> DTR or RI signals
> END QUOTE
> 
> This contrasts with:
> 
> The Pi3 hosting the usb-serial adapter has in config.txt
> bob@pelorus:~ % more /boot/efi/config.txt
> [all]
> arm_64bit=1
> dtparam=audio=on,i2c_arm=on,spi=on
> dtoverlay=mmc
> dtoverlay=disable-bt
> device_tree_address=0x4000
> kernel=u-boot.bin
> 
> which has the full-function UART for its serial console
> and is using arm_64bit=1 .
> 
> Why the variation?
> 

That machine is the terminal server, pelorus, on the LAN. Its 
internal uart does not participate in the data transmission chain. 
"Hosting the usb-serial converter" was my euphemism for terminal server.

Please accept my apologies for not proofreading more carefully!
If there is a better choice of terminology please tell me. 

Thanks for your patience!

bob prohaska