hpr-knowledge-base/hpr_transcripts/hpr1366.txt

Episode: 1366
Title: HPR1366: What I do with my Raspberry Pi
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr1366/hpr1366.mp3
Transcribed: 2025-10-18 00:20:22

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Hello, this is Nandar Geek. I picked this forum name a while back and I've been using
it because a few years ago, network, I was talking to a guy about 15 years younger than
I am who uses Linux at home. It was looking at me like a gas that like when I want to
kill a process, I do PS-EF, I pipe into CREP, searching for part of the name of the executable
or the application and then get the process number and then type kill in at the command
line myself. He just looked at me incredulously and went, why don't you use Xkill? That's
why I realized that after thinking myself as being a high tech person for a long time,
I realized that I'm more of a high tech caveman. I do geeky things in very crude, primitive
ways. I wanted to finally get around contributing a show and I haven't gotten around to the
really long hacker public radio show I want to do on how I got into Linux. I promised
it to Ken, I'll do that sometime later this year. That's in fact covers about 34 years
of time. I'll take a while to get into so I want to do something a little bit shorter
and more approachable to get started with, which is one of the suggested topics of what
I do with my Raspberry Pi. In the spirit of Dave Yates to try to do a podcast for my car,
this is like you get this done pretty much in one trip home from work. So at the moment
I have two main things I'm doing with Raspberry Pi's and I have three at home at the moment.
The first is I'm using it as my on telescope computer for start turns. So I'm an amateur
astronomer and I have a, what is by modern standards, I guess a fairly large dobsonny
telescope. So dobsonny telescope is a kind of Newtonian reflective telescope with an altitude
asset with mountains. So if it's up and down an altitude and it's been around the horizon
and Asmeth and mine's got a 20 inch mirror for European friends, 15.8 centimeter
bit mirror. So this is a, it has a fair amount of light and I like to use it to look at what
are called deep sky objects or things outside of our solar system like gaseous, nebulae
inside our galaxy, globular clusters, and over and I got our galaxy and other galaxies
inside. I enjoy looking at things like, you know, you can see better pictures on the internet
now and I get an intellectual excitement out of watching something where the light
left it 25 million years ago to get into my eye. So I have a set of digital setting
circles for my telescope and I actually have more of a telescope. I have one set of digital
setting circles. I can use it to meet them. But basically what this is is a set of digital
shaft encoders you put on the axis, the telescope that connects to a small computerized box
which I think is from some kind of microcontroller and commercial product. And it will, if you
pointed it a couple of known bright stars, it has its reference list and tell it when
you've centered the telescope on it and give it the approximate date so it can calculate
where the planets are. It will then figure out what all the coordinates are and from reading
the axes from the telescope, the shaft encoders, tell you where the telescope is pointing
or you can tell it while I want to find this object and the object is in the database through
the little buttons on the front of the unit and then it will tell you which direction you need
to push the telescope to point at it. So I was originally interested in interfacing some kind
of computer to that on the Raspberry Pi and you get to that and what this box has on the back
of it is a jack where you can plug in an adapter cable for an RS-232 serial interface and then that
can send, when queried, it can send updates on the position to a star chart program and then the
star chart program can update its position where the telescope is pointing. So I was interested in
trying the Raspberry Pi for that and I started trying using the K-stars program which is part of the
KDE educational package and it's intended to be like a desktop planetary program you can have
send random updates in the past and see what the sky looked like, use the default to today's
system clock date and I'll show you what's up you can even do specific things like set up observing
lists or say how high will this object be at midnight or what's the curve of when this
a given object will be at the highest point which might be the best time to look at it and it has
the ability to query things like that but I made the adapter cable plugged it into a USB to RS-232
converter cable and plugged that into the Raspberry Pi and couldn't quite seem to get them to talk
and probably with a few days fiddling with it of debugging I could probably work that out but I
haven't gotten around to that because what I found in the course of trying out KDE the KDE K-stars
package is it's a pretty usable star chart program on the Raspberry Pi now it means when it runs
it pegs the CPU at 100% and I've got my Raspberry Pi that he's about moderately overclocked at 900
megahertz however it's quite usable within that because it takes about 15-20 seconds to start
then you get the display up and then but the painting and zooming is quite responsive because most
of the CPU cycles when I ran a top CPU job is see where the CPU cycles were going our XOR calls so
most of that work is going into updating the display once a second because it's updating its clock
at once a second I've talked briefly on the mailing list of some of the developers about things
we might do to improve performance for on the Raspberry Pi and they were interested but they were
in the middle of like about to do a major feature freeze for a new major version and really
haven't been able to get to it so I may engage the developers a little bit later this year because
they didn't seem quite interested in using another Raspberry Pi but so what practice it takes about
as I said about 20 seconds to start up and it's open the other thing that sluggish is the
find object menu which takes about up to 10 seconds to open up when it's in full-screen mode
for a 1366 by 768 resolution display in practice I run it at about two-thirds that width I just
narrow down the window a bit to about two-thirds that width so it's almost square and then it's about
seven or eight seven or so seconds to open the find object window which is a little annoying but tolerable
but again panning dragging the mouse to new spot in the sky zooming in and out to get a look at
closer look at where some object is relative to stars is very usable in the program because what I've
been finding for the last several years is I can actually find objects quicker if I don't use the
digital setting circles so the other option in a lot of telescopes is for especially dots so
means because you basically kind of push them where you want them to go by hand is it's called the
red dot finders it's kind of a derivative of kind of thing that lots of I've used for gun sites so
it's a little optical reticle that projects a red dot more or less where the telescope pointed
there's a little adjustment Allen Allen head bolts that you you fill it with to get it to point
to where the telescope is and so once you have nowhere the telescope's pointed sky you can say look
at a star chart paper star chart or a program star chart program and say okay the object on a
look at is next a little distance away from that fairly bright star so one approach is you can point
right at the bright star and then look on the charts where some other faint stars are and what
direction they're in and move the telescope off to those until you walk your way over to the
object you want to see they call that star hopping but what I found is because I've had a lot of
practice over the years doing this I'm pretty good at judging the distances on the either on
paper to the star charts or a star chart program and being able to point the offset so okay that
looked like that object is pretty close to that visible star and taking a guesstimate pointing the
dot where I think it ought to be and after a couple of tries most of the time I can find that
scanning around the bed I can usually find the object and the other place to start chart
programs are usually if you do use the paper charts is it tells you which way is up because the
paper charts are printed out on a you know projection of the sky on your flat page and as a
course of the evening is objects rise and set the sky which direction is up and down and left
right on the axis the telescope are gonna change and having an even an even if you're not using
the star chart to find things knowing which ways up in which ways left and right is extremely useful
using paper charts that was originally what I started doing first with a netbook and now with
the raspberry pi plugged it to Motorola atrix lap doc is the display keyboard and touchpad for it
but I found over time I've gone from kind of you know 6040 using paper charts to using the
the k-stars program to about 9010 using the k-star chart my very rarely have to go back to the charts
to get it in details or look at things a little bit differently than the program displays
now they said I'm using now the the Motorola atrix lap doc since I got the raspberry pi found
great links online about that you could use the Motorola atrix was designed with like a micro HDMI
and micro USB jack on the side of it and designed to plug into this laptop and doc since I was one of
the few consumers who actually bought one with my Motorola atrix although I did at least get it
on sale so I didn't pay full price I had one lying around so I bought the adapter cables and
plugged the raspberry pi into it and find it works up pretty good it serves as a pretty good display
and I get something in excess of the six hour battery life using it this display for the and
basically you know base station for powering the raspberry pi and I sense bought another one used
on eBay for about 50 bucks so I find pretty handy to have so what I found is once I had it but
so I started using it with the lap the Motorola lap doc and I used that I had a little kind of
laptop stand that I would set next to the telescope and that's what I used this march for trying to
attempt what's called the Messier Marathon so I was referring to the fact that I like to look at
deep sky objects and the list of kind of that most amateurs astronomers start out looking at
for deep sky objects is called the Messier this so Charles Messier was a
astronomer in the 1700s and the time at that era the way you made a name for yourself as an
astronomer was to find comments that's where the action is at that's what everyone wanted to do
and so what he was I think one of the relatively early astronomers uh yeah trying to systematically
search for comments and so anytime you could discover a fuzzy object to the sky it might be a
comment on its way into the inner solar system and possibly detected before we came very bright and
claim uh fame for having discovered it but he kept finding all these other fuzzy objects in the
sky that were inner not comments that weren't of interest to him so he systematically cataloged them
so he would know which ones he didn't care about as it turned out those are some of the brighter deep
sky objects uh in the sky to look at some of the nicest things to look at with amateur telescopes
so a lot of people like to look at those and it turns out that in march in the northern hemisphere
that if you have a uh on the night of the new moon depending on the winter of the month it occurs
it's theoretically possible that you could look at every one of the Messier objects in one night as
they you have to start catching you start right at sunset in the twilight trying to catch the ones
to the west and then you have to go through all the objects in the sky and there's new ones come up
keep observing them and then catch the last few to the east uh in the twilight as the sun's
coming up the next morning so i tempted to do that this march using the raspberry pie and
k-stars the lap dock is my main observing tool and i was able to observe 94 of the 110 Messier
objects and i would have come so i would have come about two or three short that i missed
to the west because of my mustard horizon except that the uh i have a port i also have a port
eastern horizon and we had a little bit of wispy clouds come in that made the uh
pre-dawn twilight worst and i had i wasn't able to find several of the uh objects that were
coming up right at right before dawn at the end of the morning but i was very excited by doing that
really happy with the way k-stars performed all that i'll do and so i'd recommend anyone who wants to
look at a play with astronomy look at it because it has other features if you're not just
going out with a telescope like it'll download a digital sky survey photo of one of these deep
sky objects if you right click on and then display what it would look like in a large telescope
and and it's again it's intended to add for educational purposes so you can do a lot of different
things so other than just use it as a chart but i do have to caution 10 found if he wants to use it
with his children that it does do the thing he does not like which is require a lot of the kde
libraries to be installed including my sql to install i did verify that on my upmost recent
install that on a raspberry pine and what i did subsequent to the march uses i've actually now
mounted a range to mount it on the telescope itself so when i went in may of this year i went to
the texas start party which is held every year in fort davis texas and so it's a very remote region
very dark skies or amateur astronomers from all over the world travel to to to to observe
and so for that i had a pretty sizable fd manfrotto quick release ball mount for a tripod that i'd
originally gotten to do some sky photos with just a digital SLR camera and then basically mounted
that to the side of the telescope so i took a piece of plywood and then to for the support the
motor all lap dock and mounted one of the mounting plate quick release mount plates for the ball
mount on it and then used a piece of what's called open beam which is a kickstarter backed
open hardware initiative for it openly designed and to you using cheap hardware a little bit of
extrusion system for white small road of robot prototyping and making things like small 3D printers
any kind of small mechanical project and so i have a piece of that on the attached to the board
with screws and then one of the kind of connecting pieces for that which is a fiber reinforced plastic
with a couple of rubber own rings on to make its mount connection to the to the open beam piece
flexible so it it basically the back of the motor all lap dock slides into it it for my serve
some pressure to hold the lap dock down to a sheet of neoprene that i double stick taped to the
plywood and against moderate changes of angle it holds the lap dock there fairly securely
then to that i have also on the piece of open beam i've attached to the
plywood i have a small metal plate one of these small mending plates you get an hardware store
and then i have basically some another piece of open beam attached to the raspberry pie and it
has a couple of magnet secured it so i just stick it to the metal plate with magnets so that
can pop the raspberry pie off quickly when i'm not using it on the telescope and i can take it
all apart and pack it for travel or bring it inside when i'm finished observing for the evening
so i find that very useful and i've got a lot of use out of that in texas in may and i'll have a
link in the show notes to the to the site for the texas star party with some photos of it where
they i entered it into the telescope accessories competition they had and it's got the second
place for that which i was pretty happy about unfortunately the photos on the website don't show
the raspberry pie you can't see it it's on the back of the lap dock you just see the lap dock and
the ball mount attached to the telescope and the photo the other major thing i'm doing with the
raspberry pies i'm in the kind of evolving process of setting one up to in the basement of my house
to be my file server and then also it's going to handle it's also handling downloads from
cron jobs so since i do happen to live in a place it has fairly dark size it's nice for
amateur astronomy it means my internet options are very limited and what i have is
using that satellite internet this is not bad in some respects if you're downloading a single big
file it has a tolerable maximum download speed however there's a bandwidth cap that it's about
450 megabytes a day or actually you have a 900 megabyte pool per day total and it replenishes
of a rate of 450 megabytes so with some care and particularly using bit torrent where the bit torrent
clients are very easy to start and stop the downloads i can download Linux distribution ISOs but
i have to i've really it's got me in the habit of planning my data usage and it's already increased
my desire to keep my data on my server where i don't use the bandwidth and i don't need to worry
about what other companies are doing under whether the company where it's hosted on the cloud
goes out of business or changes turns of service or spends my account earning these other issues
concerned with modern people with data these days so i wanted to have everything centralized there
and the other thing i want to do is the one of the features i've used that which is kind of nice
is between two a.m. and seven a.m. local time they don't count the data you use against your
venture total bandwidth cap so if possible i want the most of my bandwidth to get used between two a.m.
seven a.m. but since i work it's not always super convenient to me being say conscious and
functioning at work the next day if i'm always staying until two a.m. start downloading jobs so
i've set up a cron job on this on the raspberry pie to run chest griffins mash potter which is
an adaptation of linked festivities mash potter podcast catcher to but the difference in mash potter
is it organizes the podcast in different directories by which podcast they are and that
syncs with how i want to uh my handle things on my my android phone which i'm using is my main
media consumption device where i'm using music players that organize things by folders to be able
to switch between different podcasts i'm listening to and possibly if i'm riding going somewhere
on the weekend with my wife or you might want to listen to an audio book and swapping back and
force between them which most most kind of i'm going to manage all your podcast podcasts for you
uh program like dog catcher don't really seem to be well suited to i kind of like handling
my own data so i've set up the raspberry pie to run the cron job to get the stuff in the wee hours
of the morning and then i synced the phone to it in the morning so i'm using two different
applications on the android phone to sync the data that mash potter is pulled in and i'm in the
middle of adjusting how i do that so the two programs i'm using on android one is called boxing
it's the simpler the two is less features but at least you're set up where you set up the ip address
and you give it basically you set up and it's set up configuration you know what the
user account is you put the password into the android app for the system for the that that account
on the computer and then you tell it what director in that computer you want to sync to which
directory on on your device or you can set it to go the other way around go from the device to
the computer so i basically have that so the you know the mash potter podcast directory then
syncs to the podcast directory i have on my android phone and that worked that's my initial tool
but i'm sort of getting ready to get back to replace it because it just sucks things in and now
i've got a nearly full 32 gigabyte SD card between that and a bunch of audio books a lot of other
things that i've pulled into the phone so i'm looking at another another option which is called
arsink backup for android it's more featured it it will set it will do the syncing without you
giving you know the username and password you you told the username and it uses the drop-bear ssh
client to keys to sync up between the two you have to create the drop-bear key and then make
sure how many of it's moved onto the phone which i've done and it has a managed you can have
different multiple different profile setups so one can be to take the the files from the camera
dcm directory on the phone and stick them onto the server which i've set up and another can be
to sync the podcast and it also has the option that you can set the flags and arsink on it
that if something is not on the source directory that's on the destination directory it will
delete it to the destination directory so i'm looking to set that up for my pod syncing
grace creating another script that'll go through and maintain a kind of mirror of the podcast
directory that only has the most 10 for most podcasts are probably 20 or 25 recent for a podcast
for hbr in that directory and that'll be what sinks to the phone because i don't want to lose the
historical archive of hbr podcasts for example um i'd like to do list of things to do when i
get more time it's going to be to sit down with the full series of uhukas how do you use word
processing programs properly and go through and set my stuff up to doing a lot of the things
that a hooker recommends because i found that a very interesting podcast but since i'm usually
listening to the podcast i'll drive you to my car i couldn't immediately apply any of it
i don't want to go through it systematically so i really get all the benefit out of that content
created by a hooker so i am in the brothel setting up a few other things on there like i've installed
the caliber ebook management program but i haven't sent it up as the to run its server continuously
so i can just point the phone at it and then download ebooks from it and i also want to try to
set it up to pull in some rss feeds for some news items things like i from sciencenews.org which
does daily updates of science stories that i find interesting so that's still to come and then
at some point i'm going to look at serving video files i'm going to start ripping more CDs and
storing them on the raspberry pie server as i go far go on down the road the other thing i've
done with the server is to set up kind of a standard samba shared that i can access to my laptop
it's in one of the other desktop computers and other things i'm gonna and i'm starting the
systematically you try to move towards a systematic backup plan a lot of my data however i really
paid a price setting up samba by trying to be lazy and using there's apparently i forget what
it's called i'll put it in the shadow so i go look it up when i get home uh there's a gtk
ui tool for setting up samba shares i love wow it's been a couple of years since i filled with
trying to set up the samba thing and i had to do a lot of checking on web references and other
things could have done right then so it would be easier if i just got to set it up with the
ui tool and so i set it up sharework and access for other computers could seem the right to it
went back into the ui tool went through all the menus could seem to find anything so then
finally after about a day and a half of messing with it i went back into uh s and b.com
and found something it was just said to say right equals no so i changed that to yes now i can
write files to it from the remote accesses to the shares i'm not sure where that was the
gui tool but my brilliant plan to save myself i've heard using the gui tool uh sort of didn't work out
and if you keep running into that periodically because there yeah i kind of i do like
they do things to command line when i know how to do it but sometimes if i don't do things regular
leads nice to have the fallback of the gui tool and that's part of one of the reasons why i'm
kind of stuck using debt-based uh Linux distributions but i like the fact that i can use apt-get
to do all the install stuff i want to do or things i know what they are that i want to install
on every computer i set up i can do that quickly to command line or set up a script but i also like
synaptics a pretty usable gui-based package manager that i could use to look for things i'm not
sure what i want to type in keywords of the descriptions of things i want to go griffling through
all the options in there and find out what i want to install and that brings me to what i'm running
up my two raspberry pi so on the raspberry pi i'm using with the telescope i'm using pi bang
and that's a derivative of raspian which is the official devian distribution for the raspberry pi
but it's uh the uh developer of that distribution liked a lot of the features that filled new
borer has done in crutch bang which i also like since i run that on my laptop and he's used
uh was a lot of the setup for open box and the hunky setup and the you know welcome to the
new computer login script that offers you to update and install a lot of things that are part
of crutch bang he's moved those into the on top of the raspian raspian uh distribution
and called the pi bang but i believe there's no formal contact between the uh a relationship
between the distributions it's just that as you make use of the excellent work that filled
new borers done and put out under a gpl license to be available to the community uh the on the server
i'm actually running raspian the base raspian at the moment because i ran into some issue and i've
run into it once before i think during one on one of my crutch bang installs and
never sorted it out and went through a bunch of options is anywhere it doesn't seem to want to let me
open um uh gooey applications has root or as soon as uh as soon or the gk sudo to run gtk uh based
uh gooey tools has root it just keeps saying that giving me problems with uh not authorized display
i went through multiple options exit not ex authority and root find the gk sudo command
a whole bunch of things and it finally just said forget it and went back to a base raspian
which seems to let me open the uh gooey applications is root and install some one of these days on my
to be released is to go back and figure out exactly what went on with that but i it's kind of
in the list of things that i don't have time to do right now so that's basically what i'm doing
with the raspberry pie and may you have an update if i ever do really get it the raspberry pie better
integrated with the tolescope uh things i'm looking at doing include using a weak controller through
an arduido as uh input device to help control the uh raspberry pies as uh something other than going
to the keyboard using the touchpad uh on the on the lap dock for that and again got several more
things i want to set up on the server and if i get a significant amount of work done there that
might be of interest or people think this is an additional progress podcast i'll follow up with that
so it's all i've got for right now and at some point this calendar year i promise kim valen
i will do my long saga of how i got into using linux
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