Raspberry Pi: should I?

[lykwydchykyn]

Yeah, this isn't about Ubuntu, but I wanted some opinions because you guys have steered me right in the past.

Since the Spring, I've been doing Arduino projects with the kids and they love it. Now my oldest wants to check out the raspberry pi.

Raspberry Pi's are cheap, right? Well sort of. You can get a Model A for $25, but of course you really want the Model B at $35. Then you need a power supply (ding!), an SD card (ding!), a wifi adapter (ding!), and a case (ding!). Of course to connect keyboard, mouse and wifi, you need a (powered) USB hub(ding!); and since our monitors are VGA, we'll need an HDMI-to-VGA adapter, but it needs to be one known to work with a Pi (because some don't, apparently) (oh yeah, ding!). Suddenly the $25 proposition is approaching a $100 proposition.

I work in IT, and have family that work in computer recycling, so we have no shortage of old PCs running (or capable of running) Linux (So, yeah, we already have XBMC on our TV PC, we already have a Debian server running this and that, etc.). I thought a Pi would be nice because of the small form factor and the GPIO connectors.

So, if there are any RPi enthusiasts reading, what do you think?

- Is there a cheap way to get up and running with the Pi, or am I right that it's going to take $50 - $60 in accessories to get going?
- Is there something really cool/educational we could be doing with the Pi that we can't do with a spare PC or an Arduino?
- Any other thoughts??

[papibe]

Hi lykwydchykyn.

I have one running raspbmc, and working as a HTPC.

I barely have made any extra expense since:

• I use my tablet charger as a power supply (Nexus 7).
• I use a wired connection (ethernet).
• I use no case (I blow compressed air over it as often as I can).
• I use a TV as a monitor.

Regards.

[Iowan]

I have a couple of Pi's. I did the Model B. eBay for cable/adapter/power supply. I had a USB keyboard/mouse combo (Pi has two USB sockets) and don't need Wifi on it yet. Mine is a bit prone to hang - dunno if the SD is not completely stable (Sandisk Ultra - Class 10), but after the first re-format/reload, I put Arch on it instead of Raspian. It's a bit trickier (for me) to get other stuff loaded onto Arch. Either Raspian came with xrdp, or i installed it - then I didn't need the monitor or keyboard... although a bit more sluggish. I also bought kits to play with the GPIO. I've used the 8in/8out card, built (but not tried) the stepper motor, and still haven't assembled the 32 I/O expander.

I also have a couple of BeagleBone Blacks that I haven't had a chance to use very much. One came with a Debian image instead of the default Angstrom Linux, and the other has an Ubuntu image on SD - which can be copied to onboard eMMC. Somewhat faster processor, but only one USB port. The cable that comes with it generates a "USB eth0" - which doesn't work on the Debian BBB, although SSH via true ethernet port works. I haven't investigated "capes" to use the GPIO (many more than the Pi provides).

I don't have cases for any of them... although the BBB fits nicely into an Altoids tin.

[lykwydchykyn]

Thanks for the replies. I guess some of those things I can do without, but the real killer for me right now is the VGA/HDMI thing. Using HDMI isn't really a practical option for us, and the only converter I've found that works (according to reviews) is $24 -- nearly doubling the price right there!

I guess I was hoping that there was something similar out there that used VGA output and cost less than (RPi + adapter), but I haven't been able to find anything.

Just thinking, if I have to spend $60+ I can get something a lot cooler and more educational than yet-another-linux-box.

[Iowan]

I bought a used monitor with DVI input for $10. Also got a HDMI cable for $10 (cheaper on eBay). HDMI-DVI adapter was ~$2.50. So, I got more hardware, but about the $24 price you mentioned. I've been using it to learn Python to control the GPIO. If/when I get the stepper card working, I may consider using a wireless adapter to build a robot.
I suppose an Arduino could probably do much the same thing, ( I don't have any of those - yet) but this is as close to the hardware as I've been in ... decades.

I'm not trying to sell you one (or the other). I got tired of buying aging computers - intending to make them my next workstation/server. At least these don't take up a much room

[v1k1ng1001]

I remember reading an article about a year or so ago about different alternatives available to the raspberry pi. You should hunt around for other options that might work better for you.

[joyousjake]

Just to say, $100 is still pretty cheap. And if he loses interest, use it as a server, or maybe hook it up to your tv and use it as your media player.

[tgalati4]

I would take one of the old PC's and put plain Debian on it, then set up a bunch of services on it. Measure the power usage with a Kill-a-watt meter. Now challenge your kids to duplicate those services on a RaspberryPi and measure the power. You go from 50-90 watts to 5-7 watts. Running a server 24/7, the RaspberryPi will pay for itself in short order. Have the kids do the cost calculations.

You are correct, The HDMI to VGA is expensive because it is a digital-to-analog conversion. HDMI to DVI is digital-to-digital and much cheaper. So find an old monitor with DVI or a cheap HDMI TV. The analog video (yellow conector) is hard to program with because the resolution is poor. It's OK for basic status or a simple front end for instrumentation.

You only need a powered USB hub if you are running USB hard drives. Mice and keyboards run OK directly.

I would like to know what cooler stuff you can buy for $60.

Most kids want to go directly into robotics--now that gets expensive.

[lykwydchykyn]

I bought a used monitor with DVI input for $10. Also got a HDMI cable for $10 (cheaper on eBay). HDMI-DVI adapter was ~$2.50. So, I got more hardware, but about the $24 price you mentioned. I've been using it to learn Python to control the GPIO. If/when I get the stepper card working, I may consider using a wireless adapter to build a robot.
I suppose an Arduino could probably do much the same thing, ( I don't have any of those - yet) but this is as close to the hardware as I've been in ... decades.

I think we've got one monitor that does DVI, so that's a possibility. It could be swapped for a VGA if I needed to dedicate the DVI to a Pi. We've done some things controlling the arduino using Python programs, but mostly by having python send serial commands to the arduino, and then writing a firmware thing on the arduino to translate the commands. I have a feeling directly coding for the GPIO in Python is a little more fun.

I remember reading an article about a year or so ago about different alternatives available to the raspberry pi. You should hunt around for other options that might work better for you.

Yeah, I tried to google up some of those articles. All the articles I found showed boards that cost more and still used HDMI output.

Just to say, $100 is still pretty cheap. And if he loses interest, use it as a server, or maybe hook it up to your tv and use it as your media player.

Erm, yeah, $100 isn't cheap in my world, unfortunately. Also I have loads of Linux boxen, like I said; I think we may have like, 8 Linux machines going in the house, and I only had to pay for two of them (the rest were given to me by friends/family/coworkers). And those two I got off a gov't surplus auction at $65 each.

Point being, you can see that dropping $100 to just have yet another Debian box (if that's all the Pi turns out to be for us) isn't the best use of funds.

I would take one of the old PC's and put plain Debian on it, then set up a bunch of services on it. Measure the power usage with a Kill-a-watt meter. Now challenge your kids to duplicate those services on a RaspberryPi and measure the power. You go from 50-90 watts to 5-7 watts. Running a server 24/7, the RaspberryPi will pay for itself in short order. Have the kids do the cost calculations.

That's a compelling point. I don't know how these machines affect our electric bill (it isn't horrendous, but who knows?); I might buy myself a Pi just for that reason. I'd hate to give it to my son just to abscond it for the family file server, though .

You are correct, The HDMI to VGA is expensive because it is a digital-to-analog conversion. HDMI to DVI is digital-to-digital and much cheaper. So find an old monitor with DVI or a cheap HDMI TV. The analog video (yellow conector) is hard to program with because the resolution is poor. It's OK for basic status or a simple front end for instrumentation.

That makes sense; I kind of figured the yellow output was not going to be a usable option.

You only need a powered USB hub if you are running USB hard drives. Mice and keyboards run OK directly.

That's good to know; I think I'd read someone complaining about having problems with peripherals without a powered hub, but you know how the internet is.

I would like to know what cooler stuff you can buy for $60.

I had in mind maybe an Arduino kit; you can get a pretty happening arduino starter kit for well under $60, with servos and sensors and whatnot.

Most kids want to go directly into robotics--now that gets expensive.

Ain't it the truth?

[1clue]

To me it depends entirely on what you want to use it for. If you want another low-powered Linux box then I'd say no. If you want a gadget controller for electromechanical experiments, then it seems to be about the cheapest way to get into that sort of thing, the arduino boards seem to be more expensive and MUCH more expensive when you start adding things that the pi already has.

I've been contemplating a pi ever since I heard of one, but for me the problem is time.

Doesn't the pi have a composite tv out as well? You could find any old TV and hook it to the yellow RCA jack, right?