PI Hard with a Vengeance

A novice explores the Raspberry Pi.

Archive for April 2013

Destroyed the SD card socket in my Raspberry Pi.

leave a comment »

image

When it rains,  it poors! For the first week, I have been chasing a bug on the Raspberry Pi. Where keystrokes from the USB keyboard are missing or are duplicated continouesly.  This bug is caused by low or no power on your USB hub. Since I have a 2 amp powered hub, I have tried changing devices looking for something that was shorted or power hungry that could be causing it.  The problem was intermittent, so I would have to wait for it to occur to try and solve it. Today it happened, so I replaced the keyboard (yet again) and started wiggling wires. I pulled too hard and yanked it from its case while the sd card was installed. The Raspberry Pi came out of the case ripping the Sd card mounts clips off.  It will no longer hold an sd card. Without an sd card it would not boot!
Found a quick fix. Took a micro sd to sd card adapter,  a little bit of epoxy and permanently mounted it in place. Put my sd card image on a new micro sd card,  inserted it and it booted right up!  Wonderful, but nothing attached to the hub would start.  No keyboard, no mouse or wifi.. Nothing!  Checked the power and it was fine, but even the LED would not come on. Tried it on a other computer.  Nothing. Ended up buying another one. Started right up!
Used it for a couple hours and not a single problem, not even the low USB power bug! My Raspberry Pi is working better than it did before, bug is gone, sd card works the same as it did before. True it is a smaller card (same 16 gigs), but it plugs into an adapter that is that used to hold the actual sd card.
Well that is part of the good news… Before I found the solution for both hardware problems, I had a moment of pure frustration and had given up for that split second. I feared it lost and ordered a second one. So in a few days it will be double the ‘fun’ when I receive a second raspberry pi.
I really am enjoying this little wonder !

Pi Hard With a Vengeance using WordPress for Android

Advertisements

Written by pihard

April 30, 2013 at 5:29 am

Arduino Bot is hot, NO IT’S ON FIRE..!!!

with one comment

image

Ok,  for 3 nights I stayed up till 3am trying to figure out the insane wiring on this thing and trying to get everything correct. Finally completed it today, typed in some sample code and get ready to test it.  I flip the switch,  The lights come on, a good sign… Then they all go out.  A couple seconds to see if anything is going to happen and….  Nothing.  Damn,  now I have to trouble-shoot and do more research. But wait,  what is that I smell?  Plastic burning?  Yep I smell plastic!  Now I see smoke coming from the wiring/mounting holes.  The power is off so what the heck?  I see more and more smoke coming from the motor compartment and can’t get to it because I tightened all the cover screws!  A race to get the cover off and remove the batteries before the whole thing goes up.
The damage was limited to melting both the battery leads coating completely off and slightly melting the wires near them.   The battery leads were a very thing stranded wire, so when it shorted they acted as a heating element or even a fuse and burned up,  maybe saving the rest of the project!
Immediately checked the boards and they seemed to operate correctly. Then spent about 3 hours chasing the short.  Everything kept coming back alright but I finally managed to trace it to the 5 mm power plug that attached directly to the arduino.   Yes,  it is something I Soldered and looked great. Even tested perfect when the cap was off… But when you screw the protective cap back on, the voltage meter went crazy… The short was in the plug!
Swapped it out for a new one,  replaced damaged wiring and even a new battery case.
Moment of truth…. The darn thing fired right up and had even retained the test code we had programmed it with!   Works as it should, runs the simple driving/avoidance software. Hopefully there will not be any future damage to the chips because of the short.  But for now, it looks great.
Next step… Take a 5 hour nap!   Tomorrow I. Plan to start figuring out how to connect the Raspberry Pi directly.  Not so it downloads the scripts from the IDE, that’s already done..  No,  we want to use the raspberry pi to run programs in Python and use the arduino to handle the physical part of the interface. The ardueno will run all the motors and sensors and the Raspberry Pi will not interrupt the sensor data and issue commands.   Hopefully!
Here’s a couple photos of the charred battery box and wiring… What NOT to do.  I’m going to take a nap… Enjoy!

image

image

Pi Hard With a Vengeance using WordPress for Android

Written by pihard

April 26, 2013 at 12:27 am

Posted in Raspberry Pi

Tagged with , , , , ,

Arduino Mega 2560 + Raspberry Pi experimental platform

leave a comment »

image

First experiment with a mobile platform using the Raspberry Pi and the Arduino mega 2560.  The kit comes from Sainsmart.com and is a very basic starter kit with the mega 2560, motor driver board and the sensor shield as well as most of the car parts themselves. I purchased them from Amazon.com for about $80 each.  Not bad when the Mega alone sells for $60+ bucks.
  We purchased 2 of them so my son and I can build them together. They have been very educational, but even more aggravating. The paperwork has to be searched out on the internet, and has been written by running another language through some translation software. Needless to say, the documents in English do not say what is intended and is very hard to decrypt. Same for the support site. The forums are updated, but it looks like the replies to customers are run through translation software. Plus user photos are missing from the forums.  The last avenue of support…. They say there is a support wiki, but when I try to log from multiple links, I get the dreaded ‘forbidden access’ error message.
  I am not alone here, everyone has problems with the wiring and getting help solving it… Almost nothing in Google searches as well. 4 paragraphs in the instructions does not help wire it… It really needs photos to show the connections the instructions can’t express.
  The vehicle is pretty straight forward and can be done from the instructions. I have worked in hobby electronics and know that I will figure it out soon, mostly because I own test equipment and know what to look for.  But for the average person entering into Arduino and robots? I would really research this kit first and understand what needs to be plugged into where,  before purchasing it. Their instructions are on the web (check amazon’s product description for the link.) be sure to read the ‘coding’ section, since that has the few paragraphs on the wiring.
  Overall, I am impressed with it and think it is well worth the money. Very configurable and can be expanded forever. If Sainsmart would develop their documents a little better, this could be the ideal entry level system at an incredible price! The way it is?…. I am going to learn more about computer hardware and electronics than I had planned too.
Stay tuned…. PI Hard!

Pi Hard With a Vengeance using WordPress for Android

Written by pihard

April 24, 2013 at 8:31 pm

Raspberry Pi

leave a comment »

image

Ran into a few problems before even getting into the programming.  I have been reading several books on python while waiting for a delivery of arduino and parts to build a robot.  Anyhow every time I have tried to enter code or update the system, strange things have been happening.  The first keyboard I kept missing keys or getting certain keys stuck in the buffer. so I replaced the keyboard and it seemed to correct the problem.  For the last 2 days I kept trying to download software to install hardware or update the Raspberry Pi itself. My internet connection kept crapping out after 3-4% of a file. (could not keep an internet connection for more than a few minutes)
So I chased software and configuration settings and could not find it.  Replaced the wifi hardware and still no go.  Then I plugged the faulty wifi dongle direct into the usb port and the keyboard into the powered usb Hub/splitter.  The Wifi started working and the keyboard started having the same problems!

It was the powered USB hub! Raspberry Pi does require a powered Hub since it does not supply enough power to run multiple USB devices on it’s own.  I had purchased the Amazon Recommended (pictured, Macally) one with my Raspberry Pi as a package deal.  The problem is that it is only 800Ma.  I thought it should be plenty, but obviously not.  Most people recommend at least 2 Amp for the hub and that is what I will be looking for now.

Well the RPI is running smooth, the OS has been upgraded and is configured to my preferences and I have been able to explore Python for a bit. The next day or two I should be getting the robot kit, so I will be able to use some real world examples and really try out this little device!

I have started a new page off of this main one as well, titled hardware. Listing all of the parts I am currently working with.  I will try and post some pictures and links for that page as well.

The Robot I ordered is the Sain Smart for Aurduino Mega2560 4wd mobile Platform. I will also try and build a page for the robot as well since the documentation is really lacking on it and it appears that no one has recorded their builds to share with others.  Real novices are having a real hard time with the document that Sain Smart Provides.  See if I can help with that as well.

Pi Hard With a Vengeance using WordPress for Android

Written by pihard

April 22, 2013 at 10:07 pm

Posted in Raspberry Pi

The journey begins… Into the Raspberry Pi hole!

with 3 comments

Rasp_turn_aroundI am a 45-year-old father of one with very little experience in programming and even less experience in electronics. My programming experience is limited to C64 and Timex Sinclair 1000 basic when both machines were new and state-of-the-art during my teen years.
Fast forward 25 years and my son wants a Raspberry Pi computer. Helping him set it up and things just start sparking and growing in my mind. The more I explore this device, the more I imagine what it could be used for. Now I own my own RPI setup and have started to explore it as a complete and utter novice.
I understand the device was designed to introduce children into the world of micro-controllers, but I can see it has much more potential. As an older adult, I think it is harder to teach ourselves and to grasp the ideas behind new technologies. But this little device and the community that supports it make it a very powerful learning platform. So I decided to document some of my adventures into the world of this tiny micro controller and see what I can create and unlock. Hopefully you will be able get something out of my experience and insights.
With grand ideas of web-connected robots and RPI controlled CNC or 3d printers to fabricate parts for prototypes, this will prove to be an exciting learning experience for “this old dog”.
Well, here we go. Enjoy the ride!

Written by pihard

April 19, 2013 at 6:40 am

%d bloggers like this: