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0 pointsChuckMcM6y ago0 comments

I have several

* Pie-hole and runs Nagios to collect information about things going on inside the network.

* One running a PiDP-11 (pdp 11/70 emulator) as well as providing MOP service to boot my DEC terminal multiplexor (it provides the boot image when the mux comes up)

* One is a stratum-1 time server using an Adafruit GPS module with PPS output. This because I got tired of both the reflection attacks and trying to manage ntp access from inside the house to outside.

* One runs RasPBX and talks to the VOIP phone that is my home "business" line.

* One sits on my electronics workbench and runs OpenOCD and allows BlackMagic Probes to export GDB as a service over the network. That lets me debug from anywhere without burning a USB port or adding additional software.

* One runs a very simple time series database and is the collector for IOT type devices that are sending various bits of information (energy use, temp, humidity, particulate levels, etc)

* One drives a display which has a dashboard of various things that the others are doing (like Nagios alerts, data trends etc) This one is a candidate for replacement as the 4K monitor would be nice here.

* One runs the waveforms live software from Digilent and hooks to an Analog Discovery 2 on my workbench. (scope, logic analyzer, etc)

EDIT: And its important to know that I boot them using the network and run them off NFS from a NAS box, the idea being that when they break I can easily swap the CPU part with a new one.

0 comments

vardump6y ago

> This one is a candidate for replacement as the 4K monitor would be nice here.

You might be able to run 4k display with an old RPi at about 8-10 Hz.

ChuckMcMOP6y ago

The Pi is memory bandwidth limited as it is, that would probably kill it completely. Even the RPi2 was really only responsive enough with a 720p display.

vardump6y ago

Maybe you could even try 4K at 6 Hz. That should take less screen refresh bandwidth than 1280x720 @60Hz.

It might work fine. You can't know unless you try.

Partial screen updates might look weird, though.

korethr6y ago

> * One sits on my electronics workbench and runs OpenOCD and allows BlackMagic Probes to export GDB as a service over the network. That lets me debug from anywhere without burning a USB port or adding additional software.

This sounds cool and interesting. Can you elaborate on the setup and some of the ways you've used it?

ChuckMcMOP6y ago

Its pretty simple really, I built OpenOCD from source on the RPi (that is just download the github repo[1] and add some libraries like libusb), when you run OpenOCD, by default it opens a gdb server on port 3333 and a telnet server on 4444.

From anywhere on the network when you start arm-none-eabi-gdb, you can type

   target extended-remote debug:3333

And poof you're connected to what ever dev board OpenOCD id debugging. Then just load your .elf file (which flashes it) and start it and you are off to the races.

Since the Black Magic Probe has its own gdb server you wrap it with nc(1) so on the Pi you run

   nc -kl 1234 < /dev/ttyACM0 > /dev/ttyACM0

and now you can connect to port 1234 on the debug server. At which point you're talking to the BMP. The ports are selectable so I typically set up as many ports as I need (depends on how many sessions I might be running) and write them on a boogie board[2].

Of course I've got that particular RasPi mapped to the host name 'debug' for that reason, the one that runs the waveforms software is named 'instruments' :-)

[1] https://github.com/ntfreak/openocd.git

[2] https://myboogieboard.com/

fnigi6y ago

In term of electricity consumption and maintenance is worth to run so many PIs?

ChuckMcMOP6y ago

The lowest power "x86" server I have found runs at about 30W, that is equivalent to about 8 RasPis (typically about 4W each, the PiDP-11 is an outlier at 8W) in the current configuration, and the RasPis are fairly distributed around my lab which would have to be done with wiring otherwise.

anotherevan6y ago

What time series DB do you use?

ChuckMcMOP6y ago

InfluxDB

j / k navigate · click thread line to collapse

0 pointsChuckMcM6y ago0 comments

I have several

* Pie-hole and runs Nagios to collect information about things going on inside the network.

* One running a PiDP-11 (pdp 11/70 emulator) as well as providing MOP service to boot my DEC terminal multiplexor (it provides the boot image when the mux comes up)

* One runs RasPBX and talks to the VOIP phone that is my home "business" line.

* One runs a very simple time series database and is the collector for IOT type devices that are sending various bits of information (energy use, temp, humidity, particulate levels, etc)

* One runs the waveforms live software from Digilent and hooks to an Analog Discovery 2 on my workbench. (scope, logic analyzer, etc)

EDIT: And its important to know that I boot them using the network and run them off NFS from a NAS box, the idea being that when they break I can easily swap the CPU part with a new one.

0 comments

vardump6y ago

> This one is a candidate for replacement as the 4K monitor would be nice here.

You might be able to run 4k display with an old RPi at about 8-10 Hz.

ChuckMcMOP6y ago

The Pi is memory bandwidth limited as it is, that would probably kill it completely. Even the RPi2 was really only responsive enough with a 720p display.

vardump6y ago

Maybe you could even try 4K at 6 Hz. That should take less screen refresh bandwidth than 1280x720 @60Hz.

It might work fine. You can't know unless you try.

Partial screen updates might look weird, though.

korethr6y ago

This sounds cool and interesting. Can you elaborate on the setup and some of the ways you've used it?

ChuckMcMOP6y ago

From anywhere on the network when you start arm-none-eabi-gdb, you can type

   target extended-remote debug:3333

And poof you're connected to what ever dev board OpenOCD id debugging. Then just load your .elf file (which flashes it) and start it and you are off to the races.

Since the Black Magic Probe has its own gdb server you wrap it with nc(1) so on the Pi you run

   nc -kl 1234 < /dev/ttyACM0 > /dev/ttyACM0

Of course I've got that particular RasPi mapped to the host name 'debug' for that reason, the one that runs the waveforms software is named 'instruments' :-)

[1] https://github.com/ntfreak/openocd.git

[2] https://myboogieboard.com/

fnigi6y ago

In term of electricity consumption and maintenance is worth to run so many PIs?

ChuckMcMOP6y ago

anotherevan6y ago

What time series DB do you use?

ChuckMcMOP6y ago

InfluxDB

j / k navigate · click thread line to collapse