Author Topic: Getting a slow start with Raspberry Pi  (Read 3250 times)

Dragon

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Getting a slow start with Raspberry Pi
« on: September 18, 2014, 00:00:47 »
Based on my interest with the Arduino that I'm borrowing, my wife decided to buy a Raspberry Pi, Model B+, for me as a birthday gift. Apparently I got a bit spoiled playing around with the Arduino kit, which included a bunch of wires and other parts that were fairly simple to start working with... my new Raspberry Pi didn't come with anything. I've been scrounging around home to find some things to use to get the thing going.

I found an old cell phone charger, that I'm hoping will be able to do the trick. Not knowing much about electronics I'm just hoping since I've read some places that some cell phone chargers don't provide enough power for the Raspberry Pi. I found a 32Gb MicroSD card that was used in a cheap tablet that we haven't used in a while, but I don't have a MicroSD card reader on my laptop, so I've plugged the card into my phone and I'm using that to copy over the OS for the Pi. That's now how the guides and intro videos said to do it, but it was all I could think of.

...

Just a few minutes ago, I finally got my Raspberry Pi powered on for the first time. The old USB cord with phone charger adapter worked. I had to go out to the living room to hook it up to the TV, since my computer monitor doesn't have an HDMI input. When I first plugged in the Pi, I saw a couple lights come on, but then they shut off, so I was worried that I had fried it already. I unplugged it and plugged it back in again and saw the lights again... although the second time it seemed like they took a little longer to come on. I still didn't see any response on the TV right away either, but within about 5 or 10 seconds I saw that the HDMI connection on the TV was getting a signal. Woohoo!

Once it booted up, there was a prompt recommending to install Raspbian. I didn't even have a mouse or keyboard hooked up yet, but I grabbed the USB mouse and keyboard that were hooked up to my wife's computer and plugged them in. Raspbian is wiping out everything on the SD card, which is good, because I couldn't get the SD Associates formatter to find it in my phone. So now I'm just waiting... watching the progress meter move slowly across the screen. Now it's starting to get exciting.

Oh... while I was searching around online for some starter videos, I came across one that suggested getting some electronics parts from Pololu, specifically for a Zumo robotics kit;D

<a href="http://www.youtube.com/v/8pEOUdUndys?hl=en_US&amp;amp;version=3" target="_blank" class="new_win">http://www.youtube.com/v/8pEOUdUndys?hl=en_US&amp;amp;version=3</a>
« Last Edit: September 18, 2014, 00:36:14 by Dragon »
"Hello IT. Have you tried turning it off and on again? ... OK, well, the button on the side. Is it glowing?... Yeah, you need to turn it on. Err, the button turns it on. Yeah, you do know how a button works, don't you? No, not on clothes." - Roy (The IT Crowd)

Dragon

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Re: Getting a slow start with Raspberry Pi
« Reply #1 on: September 30, 2014, 23:28:04 »
It's been over a week since my last post, so I thought I should write a follow up. After getting the Raspberry Pi going, I ended up placing an order from Pololu. I ordered a Zumo robotics kit, along with some other bits and pieces to get more out of my Raspberry Pi. I tried getting everything I needed based on the Raspberry Pi Robotics #2: Zumo Robot by ExplainingComputers.com, but I couldn't find the L298N motor controller on the Pololu site, so I ended up ordering a different motor driver that was recommended for the Raspberry Pi, the DRV8835.

Even though the shipment came in faster than I had expected, I got it on Wednesday after ordering Sunday night, with ground shipping, I didn't get the Zumo kit put together until the weekend. Unfortunately, even after getting all the parts together, including soldering, which I hadn't done much of before, I couldn't get the Zumo to move. I'm guessing that it has something to do with the PWM output between the Raspberry Pi and the DRV8835, but I haven't been able to figure out the right setup for the program to work. I've tried to get it worked out for a couple days (this past Sunday and Monday evening anyway) without success... and with the extra stress at work to get all the programming correct during our recent switch from using Fedex to UPS as our primary shipping companies, I'm just kind of burned out for the week.

I am still very appreciative of my loving wife getting an interesting little toy for me for my birthday. I don't want her to think that I don't like it, but it's just getting frustrating to work on some. Maybe I'm just getting too far ahead of myself and I need to step back to learning more about the blinking lights.  :-\
"Hello IT. Have you tried turning it off and on again? ... OK, well, the button on the side. Is it glowing?... Yeah, you need to turn it on. Err, the button turns it on. Yeah, you do know how a button works, don't you? No, not on clothes." - Roy (The IT Crowd)

Dragon

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Re: Getting a slow start with Raspberry Pi
« Reply #2 on: October 01, 2014, 00:03:06 »
Before I lose track of it... here's a link that I found for the L298N. I think this is the one that was used in the video, even though this one says it's for the Arduino.
"Hello IT. Have you tried turning it off and on again? ... OK, well, the button on the side. Is it glowing?... Yeah, you need to turn it on. Err, the button turns it on. Yeah, you do know how a button works, don't you? No, not on clothes." - Roy (The IT Crowd)

Dragon

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Re: Getting a slow start with Raspberry Pi
« Reply #3 on: October 03, 2014, 20:59:57 »
Here are a couple pictures of my home made Raspberry Pi case made of Lego blocks. After making this one I came across a website selling similar things, although I think mine is cooler looking, for around $40! Fortunately mine was just built out of blocks that my son had... which had been passed down from my youngest brother, who had received many from me. So I guess those blocks have now come around full circle.  8) 
« Last Edit: July 13, 2017, 17:41:41 by Dragon »
"Hello IT. Have you tried turning it off and on again? ... OK, well, the button on the side. Is it glowing?... Yeah, you need to turn it on. Err, the button turns it on. Yeah, you do know how a button works, don't you? No, not on clothes." - Roy (The IT Crowd)

Dragon

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Re: Getting a slow start with Raspberry Pi
« Reply #4 on: October 08, 2014, 18:24:58 »
Apparently HDMI to VGA is a popular converter for the Raspberry Pi. I did a quick search for "HDMI converter" and the first page I clicked I found code for the Raspberry Pi to be optimized for that converter. I also found a couple other cheaper options to go from HDMI to DVI... not sure which one I'd want to get yet... I just need something to hook up in my den since my computer monitor doesn't have HDMI input. (I've just been taking over the TV for a while when I want to do some RPi stuff.)

Anyway, here are the links to what I've found:

HDMI to VGA Video + Audio Adapter for $18.95 - This one includes the optimization code!
3ft 28AWG High Speed HDMI® to Adapter DVI Cable w / Ferrite Cores - Black for $3.33
DVI-D Single Link Male to HDMI® Female adapter for $2.28
"Hello IT. Have you tried turning it off and on again? ... OK, well, the button on the side. Is it glowing?... Yeah, you need to turn it on. Err, the button turns it on. Yeah, you do know how a button works, don't you? No, not on clothes." - Roy (The IT Crowd)

Dragon

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Re: Getting a slow start with Raspberry Pi
« Reply #5 on: October 09, 2014, 00:36:39 »
Success!!!

Yesterday I had posted a message up on the Pololu.com forum to try to get some help. Thanks to a photo that I had included, today (Wednesday) there was a reply from a Pololu employee stating that it looked like my positive and ground connections were switched around the wrong way. It seemed a little odd, since the order pretty much looked like it would be +-+-+-, but actually it was more like +-+--+ ... Oh well... that little change got it so that one motor started moving.

After running the program a second time after the change, I noticed that a wire was loose from one motor, so I took the Zumo apart and soldered the wires on again. (The other wire was on strand away from falling off before that anyway, so I took that one off to redo too.) I found that one motor would work, but it was the opposite of the one that worked before, so I checked around a little more and found that my soldering job on the motor control board wasn't solid where the Motor 1 connection was. After soldering that I was able to get the motors going, which was soon after my family arrived home for the evening, so Isaac was able to participate some in reassembling the Zumo and even tried a little more programming to get the Zumo to move around some.
"Hello IT. Have you tried turning it off and on again? ... OK, well, the button on the side. Is it glowing?... Yeah, you need to turn it on. Err, the button turns it on. Yeah, you do know how a button works, don't you? No, not on clothes." - Roy (The IT Crowd)