Maker

Next Thing CHiP as a Twitter Bot

twitter-logoThere was a post that came across on Medium recently, How to Make a Twitter Bot in Under an Hour.  It’s pretty straight forward, though it seems to be pretty geared towards non “techie” types, mostly because it’s geared towards people making the bot on a Mac and it uses something called Heroku to run the bot.  Heroku seems alright, except that this sort of feels like an abuse of their free tier, and it’s not free for any real projects.

I already have a bunch of IOT stuff floating around that’s ideal for running periodic services.  I also have a VPS is I really wanted something dedicated.  So I adapted the article for use in a standard Linux environment.  I used one of my CHiPs but this should work on a Raspberry Pi, an Ubuntu box, a VPS, or pretty much anything running Linux.

The first part of the article is needed, set up a new Twitter account, or use one you already have if you have extras.  Go to apps.twitter.com, create an app and keys, keep it handy.

Install git and python and python’s twitter extension.

sudo apt-get install git

sudo apt-get install python-twitter

This should set up everything we’ll need later.  Once it’s done, close the repository.

git clone https://github.com/tommeagher/heroku_ebooks.git

This should download the repository and it’s files.  Next it’s time to set up the configuration files.

cd heroku_ebooks

cp local_settings_example.py local_settings.py

pico local_settings.py

This should open up an editor with the settings file open.  It’s pretty straight forwards, you’ll need to copy and paste the keys from Twitter into the file, there are 4 of them total, make sure you don’t leave any extra spaces inside the single quotes.  You’ll also need to add one or more accounts for the bot to model itself after.  You’ll also need to change DEBUG = TRUE to DEBUG = FALSE as well as adding your bot’s username to the TWEET_ACCOUNT=” entry at the bottom.

Once that is all done do a Control+O to write out the file and Control+X to exit.  Now it’s time to test out the bot with the following…

python ebooks.py

It may pause for a second while it does it’s magic.  If you get the message ” No, sorry, not this time.” it means the bot decided not to tweet, just run the command again until it tweets, since we’re testing it at the moment.  If it worked, it should print a tweet to the command line and the tweet should show up in the bot’s timeline.  If you get some errors, you may need to do some searching and troubleshooting, and double check the settings file.

Next we need to automate the Twitter Bot Tweets.  This is done using Linux’s built in cron.  But first we need to make our script executable.

 chmod 755 ebooks.py

Next, enter the following….

sudo crontab -e

Then select the default option, which should be nano.  This will open the cron scheduler file.  You’ll want to schedule the bot to run according to whatever schedule you want.  Follow the columns above as a guide.  For example:

# m h  dom mon dow   command

*/15 * * * * python /home/chip/heroku_ebooks/ebooks.py

m = minutes = */15 = every 15 minutes of an hour (0, 15, 30, 45)

h = hour = * (every hour)

dom = day of month = * = every day and so on.  The command to run, in this case, is “python /home/chip/heroku_ebooks/ebooks.py”.  If you’re running this on a Raspberry Pi, or your own server, you will need to change “chip” to be the username who’s directory has the files.  Or, if you want to put the files elsewhere, it just needs to b e the path to the files.  For example, on a Raspberry Pi, it would be “python /home/pi/heroku_ebooks/ebooks.py”.

If everything works out, the bot should tweet on schedule as long as the CHIP is powered on and connected.  Remember, by default the bot only tweets 1/8th of the time when the script is run (this can be adjusted in the settings file), so you may not see it tweet immediately.

This is also a pretty low overhead operation, you could conceivably run several Twitter Bots on one small IOT device, with a staggered schedule even.  Simply copy the heruko_ebooks directory to a new directory, change the keys and account names and set up a new cron job pointing to the new directory.

My DIY Dance Dance Revolution Hardpad

IMGP0429Something like ten years or so ago, I built my own hardpad for use on Dance Dance Revolution and Stepmania.  Most of the pads that are easily bought are “soft pads”.  These vary in quality, I have a couple of pads that are pretty light weight and plastic I used ages ago.  These pads tend to get damaged pretty easily, especially when wearing shoes, and slide all over the place when playing.  When i used mine in college I actually taped it to the underside of the rug in the dorm and taped out the grid of squares on the surface, so I could play using my shoes.  I’m sure the people living below me loooove that.  Probably as much as I loved the people above me who played dice constantly.   Some more pricey are made of a thicker though still pliable rubbery material.  These mats slide around less due to the grippy nature of the material, but they can get worn out and damaged by the rough beating of shoes.

The ideal pad is a hard pad.  These can run hundreds of dollars on-line.  They also tend to be large and bulky and heavy.  Shortly after i had finished in college I decided to employ me newly acquired Engineering design skills to build my own Hard Pad.  The electronics part was easy.  I went to the local used game store and asked for the cheapest used PS2 controller they had in stock.  The guy behind the counter actually asked if I was planning to build a DDR pad with it, which was funny since I was.

The pad itself was a bit trickier.  I’d studied several design ideas on-line that others has built.  I wanted something that was less bulky than most of the pads I’d seen.  I also wanted to keep costs down somewhat, which meant using a little material as I could and not having to invest in a bunch of expensive triggers to wire into everything.  The trigger is the key component of course, since it registers the steps when playing.  The dead squares are all just plywood covered in sheet metal.

The sheet metal is also what I ended up using to build the triggers for the step squares.  When you press a key on a video game controller, all that happens is that an electrically conductive pad is flattened and shorts the connection between two copper pads on a PCB board.  When the electrical short is made,  current can flow which causes some chip somewhere to register the button press.  For my step pads, I simply enlarged this process by attaching plates of sheet metal tot he base and to the bottom of each step pad.  To give the pads some cushion and bounce, I placed strips of weather stripping bought at the hardware store between the base and the pad.  Stepping on the pad creates more than enough weight to overpower the weather stripping causing the two sheet metal pads to connect and trigger, stepping off allows the weather stripping to flex back up pushing the pad back to a neutral, unconnected position. I took some CAT 5 cable and soldered it to the sheet metal contacts and the appropriate parts inside the PS2 controller to replicate the button press action inside the controller.

Everything else was cutting wood, attaching corner brackets and attaching sheet metal.   Here are some old photos of the process.

The general construction was sound, but it had a few issues that I never really got around to fixing until more recently.

In the original design, I soldered the connections for the step pads tot he controller’s D-pad.  Mostly because the solder points were larger and easier to solder to.  This had some unintended side effects that made the game unplayable at any higher difficulty level.  By design, the controller never expects opposite D-Pad buttons to be depressed at the same time.  That is, it doesn’t expect the player to press left and right at once, the D-Pad generally controls movement in most games, why would you need to press opposite ways at once.  Dance Dance Revolution has “jumps” in more difficult stages, these are sequences where two arrows have to be matched at the same time, as in “jumped on”.  Since the D-pad doesn’t register left+right or up+down, these jumps would never register and were always considered a miss.  Kind of game play breaking in the case of DDR.

I also wanted to add a box to the set up, to replicate the buttons on the front of a real DDR machine used to select songs and options.  Not something important, but it would add to the effect, and if I ever got really ambitious, I could build a whole cabinet someday.

The other major issue, when I built the original design, I didn’t really do any real management of the wires between the controller and the pad.  They kind of strung around on the sides, they were all too long, and the controller itself was permanently attached to the pad, making moving and storing tricky.  I wanted to make the controller bits, detachable.

I’ve since solved all of these problems with some improvements, all somewhat related.  First problem was the triggers not working for jumps.  This was simple but tedious.  I needed to reqire the buttons from the D-Pad to the face buttons (Triangle, Circle, Square, X).  These work just fine when pressed together, lots of games have combinations where you have to press several buttons at once.

Please Parton my Shoddy Soldering

During this process, I also pitched the controller shaped housing and stuffed everything in a generic electrical project box.  I soldered the 4 shoulder buttons to 4 buttons attached to the box lid, to be used to interfacing with the menus.  Problem 2 solved, everything is in a nice box.

IMGP0430

The last bit was to make the controller easily detachable.  There are 4 pads, each with 2 wires, for a total of 8 wires going from the controller to the pad itself.  I was already using CAT-5 cable for the wire, it had 8 wires in it, so I attached an CAT5 end on the controller piece and a CAT5 receptacle to the dance pad.  Now the two were easily separable and securely attachable.

The ultimate test of course, does it all work?

stepmaniaresults

I’ve run several sets of tracks using the new set up and it certainly does work.  My DDR skill needs a lot of improvement to get back up where it was at my peak, but the pad itself works just fine.  Which is sort of the point, because it really is a fun way to get a pretty good workout in a short period of time.

 

 

Saving a Slice of Raspberry Pi

Raspberry_Pi_LogoSo of all the things on the network, the DNS and DHCP server are pretty important.  Especially because my experience has been the router the ISP provided is kind of mediocre at doing the DHCP job.  So when the Raspberry Pi I’ve tasked with doing the work started flaking out I was a little worried.

After some investigation, it seems the SD card had lost a sector, or whatever the equivalent thing is to a sector on flash memory.  These things do have a bit of a limited life and this particular one was a small 4GB card that was a little older.  Four gigabytes isn’t even above the recommended size for the Pi, but I knew I wasn’t planning on putting a lot on it.  Problems arose when it started dying though.  There actually isn’t much using the PiHole, some of the things my wife does with coupons and such I suspect might get blocked and I don’t want the headache of dealing with trying to manually whitelist things and complaints that this and that isn’t working.  The DHCP is another issue.  When the DHCP server disappears, it seems anything using it simply can’t connect to the internet.  I have a lot of static assignments but there’s quite a few assigned by the server.

I may have to look into setting up a secondary backup server, maybe on one of the CHIPs even.

I started out simply re-imaged Raspbian onto a fresh card and setting things up again following the tutorial I had posted.  Everything went pretty smoothly except that I was now out my old config file and would have to go through the hassle of recreating all of the changes I’d made adding and removing devices.

So I went with a new strategy, why not just clone the old card to a new one.  Unfortunately, Win32 Disk Imager, the recommended tool for imaging these SD cards, couldn’t read the whole card, it got hung up and failed partway in.  So I turned to my laptop and Linux hoping for something more robust, which I found in ‘dd’.  It probably stands for “Disk Duplicator”, but don’t quote me on that.

I started running dd to make an image of the old card to put onto a new card, unfortunately, it also failed, like Win32DiskImager.

Back to Square One…

After some searching, I found this post suggesting something called ddrescue.  Most of it wasn’t anything I needed aside from the following.

sudo apt-get install gddrescue
sudo ddrescue -v /dev/sdb /dev/sdc

A few things of note.  My laptop, like many, has a build in SD slot, I added a second using my USB card reader.  I opened the disk manager to get the path to each card, /dev/sdb and/dev/sdc.

This command also hit an error at the same point as both Win32DiskImager and the “dd” command, but it pushed on through, recovering everything else.  At this point it’s a matter of hoping that one bad spot wasn’t int he middle of an important file.

Internet of Things, Internet of Stuff

I wanted to take some time to touch on my every changing collection of Internet of Things style devices.  Honestly, it’s kind of iffy what constitutes an “IOT” device, but for the most part I’m sticking with “cheap” and “non traditional computing devices”.

The chief player among these are of course…

The Raspberry Pi

I’m up to 5 Raspberry Pis, a B+, two B2s, one B3, and one Pi Zero.  I have already discuss these quite a bit so they don’t need a ton of additional discussion.  The B+ still operates my DNS/DHCP server, one B2 still runs my IRC stuff, one B2 still runs a Minecraft server.  I actually have not yet come up with a good use for the B3 and Zero yet.  I’ve started messing with Windows 10 IOT on the B3 a bit and there is a Retro Gaming GameBoy project using the Pi Zero floating around on Reddit I may have a go at.

Arduino

If Raspberry Pi is the king of IOT, then Arduino is definitely the Queen. I’ve kind of dropped out of doing Arduino projects a bit and dismantled most of the ones I had built.  Other than adding a WiFi enabled board to my set (by mistake, I thought I was ordering a Shield not a board), not much has changed on my Arduino library.

i did try to build a little digital hourglass project I found online but it’s not going super great.  Stay Tuned for More

Next Thing’s CHIP

CHIP is still one of the most annoying and impossible to search for terms online.  I’m up to three CHIPs now, I’ve received my second Kickstarter CHIP and my VGA DIP.  I’ve still been having some bad luck getting my CHIPs to do much of anything.  I tried to build an Amazon Alexa with no luck in the end after a ton of troubleshooting.  I’ve been trying to get Synergy combined and running on one to let it work with my multi monitor set up.

Now that the Kickstarter campaign is more or less finished and the CHIP is reaching a wider audience I’m hoping it starts to get more support online.

Remix Mini

Another kickstarter product, the Remix Mini is a small computer that runs Android as a desktop.  It works pretty well, I mostly used it last year while traveling for work in the Hotel Room.  I have not touched it since, for one simple, stupid reason.  The HDMI output doesn’t support any of my HDMI to DVI cables.  I can’t plug it into a regular monitor, so I just have… not used it.  I could plug it into a TV but it’s effectively a simple desktop machine and doesn’t work as well for a “lean back” experience.  Maybe if I had a wireless KB and Mouse it would work better.

It’s a shame to because I was really looking forward to this one and it runs a lot of my apps surprisingly well.

ChromeCast

I picked up a Chromecast last year on Black Friday. I used it a bit but in the end, it’s ended up in a drawer.  It’s just too much of a hassle and it caused too many problems.  First off, the hassle.  My crappy old Nexus 7 is partially to blame here but in general the lack of any built in interface is just a flat out pain.  Having to dig out my tablet to use it is a pain.

Worse yet, it was causing problems with the Wireless in the house.  I disabled guest mode which eliminated the problem (eliminating the interference) but it’s still kind of lame that it was an issue to start with.

Kindle Fire Stick

A more recent addition to the network, I added a Kindle Fire Stick.  This is effectively the same as the Chromecast, without the hassle and bull shit of needing a separate device to use it.  It’s not completely without it’s issues but it works pretty well.  The main problem I’ve had is that it loses signal, a lot.  It doesn’t work as all directly hooked to my HDMI switch and at this point it’s cabled out and laying out on the floor behind everything to get it away from any interference.

It runs Amazon videos, which I don’t really use, it runs Netflix, which is used a lot.  It also works well with the fact that I buy my MP3s primarily through Amazon.  Another nice bonus, I use Amazon Cloud to backup all of my Photos, so they are all available through the Fire Stick now to view on the TV.

SteamBox

 Another newer addition is the SteamBox.  Specifically, the cheap streaming box.  It works pretty nicely.  I haven’t had a chance to really put it through the loops yet but my first tests worked well.  I’ll probably do a more in depth write up at some point on it.

NextThing CHIP and Raspberry Pi Zero

Raspberry Pi Zero and Next Thing's CHIPI’ve already briefly discussed my NextThing CHIP computers before. A few weeks ago I was purchasing a Raspberry Pi 3 and found that the store had Pi Zeros in stock as well, so I tossed one on because, hey, $5, and they are apparently hard to find.

These two little devices are pretty similar, but at the same time so different.

Both are small computers, not just microcontrollers like an Arduino, but little Linux machines. Both have GPIO pins, both can be used as a regular “desktop” if you wanted, both cost less than $10… Mostly…

Raspberry Pi ZeroThe cost is where things get tricky, especially for the Raspberry Pi Zero. Upfront, the Pi Zero is only $5, which looks great on paper, and it’s still pretty cheap. That five dollars gets you a small flat circuit board with a few low profile ports on it. Chances are you’ll need a power supply, if you want to be able to configure it at all you’ll also need a way to plug a standard USB hub for keyboard and mouse into a micro USB port. The display out is a mini HDMI port, which you’ll likely also need an adaptor for. The Pi Zero also doesn’t have any sort of case on it. All of this is stuff that you may or may not need, you might have on hand, or, if you’re programming many Zeros, you can reuse the adapters and parts on all of the Pi Zeros you want, once configured.

The point is, after picking up even some cheap accessories, you’re probably looking at closer to $15 for a Pi Zero. Still cheap, just not quite AS cheap.

Next Thing CHIPThe CHIP on the other hand, is $9. It has built in WiFi and Bluetooth, it comes with a little plastic case for the underside of the board, and it comes with an RCA adapter. The RCA isn’t ideal and an HDMI or VGA attachment are both coming (for $10-$15) but the RCA is usable for setting up WiFi easily for SSH or VNC access. It even has built in storage. For $9, you’re pretty much up and running right out of the box. The Pi Zero is actually kind of useless all on it’s lonesome.

That doesn’t necessarily mean the CHIP is better.

Both The Raspberry Pi Zero and Next Thing’s CHIP run an arm based version of Debian (by default, but this could be changed), thus both have a lot of common in terms of what sorts of software can be used. The CHIP however seriously lacks the Raspberry Pi’s strong community. I’ve not been able to find any decent resources for how to even use the GPIO pins, for example. I had hoped to use one of my CHIPs for a project in the garage but I’ve hit some roadblocks.

chipdesktopI’ve actually had lots of roadblocks with the CHIP. Initially they were unstable, requiring a firmware update. I’ve had many strange problems getting software packages to work properly, even when following tutorials put out by others. The closest I’ve come to finishing a project is making a homemade Alexa clone. Even after buying identical parts (Mic and Button really), after trying many fixes and even wiping the thing out and starting from scratch, I still get errors with the Audio about “Period too large”.

Everything being built in is really convenient though. I honestly haven’t come up with any ideas yet for what to do with my Pi Zero. It ends up with some goofy dongles all over it to make it functional and I have 4 full sized Raspberry Pis at my disposal for other projects. I’ve seen an interesting Game Boy emulator build using the Zero I will probably try but so far, it’s pretty much just been running quietly on my workspace counter.

Personally, I think that ultimately it comes down to there is a point where these things become too cheap or small to be useful, at least for my needs. The sorts of projects a smaller board like this may be useful for feel like they would be better suited for an Arduino. Most of the projects I use my Pis for amount to “Hardware VMs”. Single task servers that can easily be repurposed or swapped out (using SD cards).