Specifying IP address in cmdline.txt in situ

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
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g3yjr
Posts: 23
Joined: Sat May 23, 2020 1:37 pm

Specifying IP address in cmdline.txt in situ

Post by g3yjr » Fri Jul 03, 2020 11:57 am

I had boxed up the RasPi and then discovered that in order to try OBS that I needed to specify an IP address on a file on the SD card buried in the box. https://wiki.batc.org.uk/OBS_-_Open_Broadcast_Studio
I wanted to avoid dismanteling it so I experimented and found the following approach using console mode seemed to work. I used a remote device, a PC running Linux in my case, to run console mode.

In menu M2, use the Info button and make a note of the IP address. Make sure you have a network connection between the RasPi and your remote device.

Start a putty session on the remote device. In PuTTY Configuration, enter your noted IP address in Host Name (or IP address) and click Open.
Login as: pi
password: raspberry

You should see Portsdown DATV TX etc.
Select Shutdown and reboot options.
Select Exit menu to command prompt. You should get a Linux prompt like pi@raspberrypi:~$. Enter:
cd /boot - the prompt will change to /boot $
dir - this should list cmdline.txt as one of the files.
sudo nano cmdline.txt - opens a text editor. You should see a big long line of text with commands in it. Use the arrow keys to navigate towards the end of the line and just after rootwait type in ip=192.168.2.47 (substituting the IP address that you want to allocate instead of 192.168.2.47). Space it like the other commands. Enter ctrl-O to Write Out and save the amended file, then ctrl-X to exit the nano editor. Enter exit to quit the putty session.

When you reboot Portsdown, M2/Info should show the new IP address.

I don't know my way round the Portsdown system & I'm not a Linux expert, but I am sharing this in case it helps.

Jabi
Posts: 25
Joined: Sun Jun 14, 2020 3:23 pm

Re: Specifying IP address in cmdline.txt in situ

Post by Jabi » Fri Feb 19, 2021 9:10 am

Dear sir:
Which IP should I enter? The one on the PC with OBS Studio? The one with Pluto? Raspberry 4 with Portsdown 4?
73,s de Jabi, ea2aru.

g0mjw
Posts: 1492
Joined: Sat Sep 20, 2014 9:15 am

Re: Specifying IP address in cmdline.txt in situ

Post by g0mjw » Fri Feb 19, 2021 9:42 am

Jabi wrote:
Fri Feb 19, 2021 9:10 am
Dear sir:
Which IP should I enter? The one on the PC with OBS Studio? The one with Pluto? Raspberry 4 with Portsdown 4?
73,s de Jabi, ea2aru.
If you want to give the PI a fixed IP address then it's the IP address you want to give the PI. This command set's the address the PI uses on the network.

Jabi
Posts: 25
Joined: Sun Jun 14, 2020 3:23 pm

Re: Specifying IP address in cmdline.txt in situ

Post by Jabi » Fri Feb 19, 2021 4:47 pm

Ok. many tnx for all, de Jabi.

g8lce
Posts: 183
Joined: Sun Dec 06, 2015 10:26 am

Re: Specifying IP address in cmdline.txt in situ

Post by g8lce » Sun Feb 21, 2021 9:57 am

You should use something like Advanced IP Scanner (works on a Windows 10 computer) to look at your LAN network addresses before deciding which fixed IP address you want to use (if you want a fixed IP address). This will show you the address range you are using for your LAN network and the address of the things already on your network. Usually it will be 192.168.xxx.(1 - 254). The first three sets of numbers need to be the same for the fixed address so 192.168.xxx (where xxx is a number between 1 and 254) and the last set of numbers will be different to any of the ones already on your LAN network.( but between 1 and 254 but usually best at the lower end).
For example my LAN network has adresses 192.168.123.(1-254). My computer is 192.168.123.36 and the router (which sets the addresses if they are not fixed) is 192.168.123.254. One of my Raspberry PIs is at 192.168.123.38.
The LAN network address of a Pluto defaults to 192.168.2.1 and putting this on my network will not be seen by my computer unless I change it to something like 192.168.123.1

(Some LAN networks use addresses like 10.1.1.24 so if you have this then your LAN network address will need to be 10.1.1.(1 - 254))


Martin G8LCE

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