On 31/7/25 08:08, Steve Dondley wrote:
On Jul 30, 2025, at 7:59 PM, mick.crane <[email protected]> wrote:
I've never really known what a serial console is.
Say in relation to a Raspberry Pi or Arduino
I assumed a serial console was a device with a screen and keyboard.
When people talk about a serial console they are talking about
connecting a Debian PC to a device with a parallel, wired cable to a
parallel port or an adaptor on a PC and emulating this console thing
with software?
Like a telnet connection?
mick
Serial means one bit after another. Console is an old school term for
a computer control panel on old mainframes. As those died out, the
word “console” morphed into meaning your display/keyboard/mouse which
can often be serial input/output devices. There are various ports for
connecting a serial device to a computer.
The serial interface RS-232 was invented to connect a Data Terminal
Device (DTE) an a communications device (DCE).
In most incarnations the DTE was a teletype or video terminal, while the
DCE was usually a modem.
The RS-232 Standard specifies +/- 12V as the nominal signalling level
(actually above +3V and below -3V). The standard also specifies a 25 pin
connector (DB-25) with additional pins for out-of-band signalling, such
as DTR which is asserted by a DTE to indicate it is operating.
The standard is for DTE to DCE but many people bodged it to allow two
DTE to communicate, using so called 'null modem' cables etc.
The implementation for Pi allows it to act as a DTE or DCE with 4 wires,
Tx, Rx, VCC, GND. An additional pin can used to inhibit sending data.
It is important to note that the Pi Serial terminal is not the same as
the SPI or I2C communications also used on the device.
The Pi Serial terminal can be used to debug bootup and to communicate to
other serial devices such as industrial controllers, usually using
RS-485 rather than RS-232
