Lipo Conversion Part 2

So I had such great success turning my battery drill into a lipo powered device I thought I'd give something else a go.

I've got a headlight for my mountain bike which has a cree LED in it. Its fantastically bright but its hard to mount it on the handle bars and have it point where I want it to and also the cord is long and gets in the way and finally the battery pack is big and bulky and takes ages to charge. Looks like a good time to break out the lipos and see if I can sold all those problems at once.


Step 1.
The light in its unmodified state.

Step 2.
Cut off the normal plug from the light and solder on a plug that matches the plugs on your lips. I'm using deans plugs here. I chose this 2S 1300mah battery because the voltage the light was supposed to work with (according to the writing on the battery pack)  was was 7V and a 2S is close enough.

Step 3.
Cut and glue a mountain bracket onto your helmet. I did this because mounting it here made a lot more sense to me that mounting it on my handle bars. this way it pointed where ever I wanted it to.

Step 4.
On the back I glued a little bit of foam as padding and a Velcro strap to hold the battery in place and to offset the weight at the front on the helmet.

Step 5.
All ready for riding at night! It charges faster and is way more useful than the original set up. Plus while I was at it I removed the little green LED inside the on button of the light to prevent battery drain when it's not actually turned on. The other good thing about this set up is I can use my lipo checker to see how much charge is left in my battery before using the helmet so I know I've got enough power to make it through the ride. I've also discovered that 3S batteries work with this particular light.

FrSky Taranis Antenna Upgrade Part 2

Well it seems that I am unable to stop modifying my FrSky Taranis so here's the next step.

Firstly I do not take credit for the design of this antenna. That came from the great IBCray and his tutorial for the calculations, theory and measurements can be found here. So I'm not going to go over those again. This is just my build log and application of his design. So that being said lets get started.

Things you'll need.

For the antenna:
1. A small coax cable
2. Copper or steel wire, about 14 AWG
3. Metallic plate
4. Two Nylon bolts
5. Plastic container (optional as this is just the cover)

For the antenna mounting (this is just my solution but many others would work as well):
1. 12mm x 12mm square wooden dowel.
2. Two M3 bolts (atleast 30mm)
3. Heat shrink


Other:
1. Heat shrink
2. Hot glue
3. Solder


Lets get to the modding......




Step 1.
Cut the backing plate and the wire. I used G10 board for the reflector plate.

Step 2.
Start bending the wire at the section lengths for a 2.4 Ghz (see the IBCrazy thread for the calculations to get the dimensions for your frequency)

Step 3.
The reflector plate and the resonator.

Step 4.
Drill a hole in reflector for the coax cable and also mount the nylon bolts to hold the resonator.

Step 5.
Strip the coax cable back and solder the shielding to the reflector.

Step 6.
Solder the resonator to the coax cable and glue it to the nylon bolts

Step 7.
Glue the coax cable and nylon bolts to the back of the reflector and glue the plastic container to the front of the antenna.

Step 8.
You'll need to get the coax cable into the Taranis so instead of drilling into it I ran it though the hole in the ORX module left when I did the antenna mod on it.

Step 9.
New antenna connected to Taranis.

Step 10.
Solder new coax cable to the Taranis module board where the other antenna was connected.

Step 11.
Antenna ready to be mounted.

Step 12.
Cut four sections of the dowel about the length of antenna. Doesn't matter if they are a bit shorter.

Step 13.
Clamp them together and drill a hole where they meet at the top about 4mm in diameter.

Step 14.
Take the handle off the Taranis and put some heat shrink over it to give the clamp more grip.

Step 15.
Drill mounting holes in the dowels just bellow the main semi holes.

Step 16.
Screw the mounts together with the M3 bolts and clamp them to the handle of the Taranis.

Step 17.
Glue the new antenna to the mounts.

Step 18.
All Done!

Note: this reduced my SWR reading down to 16. This is probably fine but I read that to get it even lower you need to make sure that when you're soldering the coax cable to the board you want to expose a very very small amount of the core and make it as close as possible to the soldered shielding.

FrSky Taranis Antenna and Sliders Upgrade Part 1

Well if you've read previous articles on this blog you'll know that I can't seem to stop modding my FrSky Taranis. It really seems to lend its self to modification. I've got some more planed as well.

Enough of that though, here's how to upgrade the main antenna of the Taranis and also the sliders. You might want to upgrade the sliders if you bought one before about February in 2014. Until that point they were shipping them with really cheap and nasty feeling sliders on the sides but fortunately you can buy the new sliders from places like Aloft Hobbies pretty cheaply.

Step 1. Things you'll need.
1. A pair of new sliders
2. A 5dB Omni Direction Antenna or A 7dB Patch Antenna
3. A coax cable (I would order this longer one because I ended up cutting the shower one too short and having to use another cable I had lying arund

Step 2. 

Open up the Taranis by removing the screws in the back and take out the sliders and switches at the top left and right. Be careful unpluging these from the main board as they are quite tight. I used a knife to get in and loosen the catches. 

Step 3.

Remove the hot glue blob over the soldered joint with a knife.Mine came off rater worryingly easy.  

Step 4.

Unsolder the coax cable for the antenna that's already there and then remove the main antenna. This will just slide up the top of the Taranis case as long as you use some pliers to squeeze the base of it so the little lugs come free.

Step 5.

Clean up the joint where the cox cable will be soldered on and add a little solder to the ground plates which are the two larger joints beside the little one in the middle which is the what the core wire will be attached to.

Step 6.

Get your coax cable ready. I cut off the little connector because I really don't think i'll be needing to change the connector any time soon so I just prepared it for soldering by feeling back the metallic shielding on the outside and making it into two wound strands which I've covered in solder as well as a little on the core strands to make them easier to connect to the board. 

Step 7.

Hot glue the coax cable into the hole where the old antenna came out of. I put a little bit of scrap wood underneath the hole to stop the glue from running down into the Taranis body

Step 8.

The coax cable hot gluded in place. 

Step 9.

Solder the outer shield joints to one or both of the outside connectors on the board and solder the core wire to the active connector on the board (the one in the middle)

Step 10.

Place a bit of hot glue (and do a better job than they did at the factory) on the joint for the coax cable.

Step 11.

You'll need to take the switches out to remove their wires and plug into the new ones which are attached to the new sliders. 

Step 12.

Put the new sliders back into the case, put the switches back in (make sure you didn't turn them around or put the back in the wrong side) and you're done. :)

Some notes:

One thing which I'm still investigating and testing is that SWR values with the new antennas are a bit higher than they were with the original stock one. I've read on the OpenTx website that this isn't a problem as long as it doesn't go about 50, however to my mind its still indicative of an imperfection somewhere so I shall keep investigating and make some more posts when I work it out.

FrSky Taranis Antenna Mod

So the FrSky Taranis is an awesome radio but with a little modding you can make it even better. Due to its ability to to use both its internal FrSky module and another one in the port on the back it has amazing flexibility. The only problem with using an external module is the fact that the antenna sticks out the back and won't let the radio sit flat on its handle. It also gets in the way when you try to carry it by the handle.

So here's what I did....

1. Take the module out of the radio and also take the battery out so you don't short anything out.

2. Unscrew the six screws in the back of the radio and open that puppy up. Always a little scary I know but this radio is designed to be opened up so you can change the mode if you want to.

3. Open up your module by unscrewing the antenna and the four screws in the top. I'm using the ORX DSM2 module from Hobby King so I can fly my Nano QX and my old foamies with this radio. The little antenna cable you here see I got from eBay for a few dollars. Just get a RP-SMA antenna cable like this one from an electronics store or eBay.

4. Put the module shell back in so you can drill through into the inside of the Taranis like I've done here. The hole just needs to be big enough for the small end of the cable to go through. Be careful when you drill through that you don't hit anything inside the Taranis. If you drill through here like I did you should be fine.

5. Now drill a hole in the top of your Taranis. This can be anywhere you want the second antenna to be mounted. I put mine up here behind the main antenna. The hole needs to be just big enough to put the big threaded end of the RP-SMA connector through with out letting the whole thing (the collar and nut) fall through.

6. Put the big end of the cable though the big hole and the little end through the little hole. Once you've got the big end though, put the washers and the nut on the top to stop if falling back into the Taranis.

7. Connect the little end of the cable to the board in the module and put the board back in the module case.

8. Close the module up and put it back in the case. You can close the hole left by the antenna with some tape if you want.

9. Screw the second antenna onto the SP-SMA cxonnector and close the Taranis case. One thing to note when putting the screws back in. If you don't hold the two halves together the screws won't grab in the front half and they will push it open. So just keep the two halves held together while you do it. Also make sure you put the top two switches back in the right way, brown wire to the top (like all the others).

10. All done!

11. It works :)

Lipo Conversions Part 1

If you're into RC at all you're mostly likely know what LiPo batteries are. If you're not have a look here

Having a whole load of these batteries in my garage I've discovered that you can do a whole lot more with them than power RC aircraft. 

So my first LiPo conversion project was to resurrect my trusty battery drill. Its a great drill however it suffers from the same problem that a lot of battery drills do in that if you don't use it all the time the batteries die eventually and also the batteries take a very long time to charge. So I converted mine to run on Lipos and now it not only charges much faster, but I can buy very cheap replacement batteries for it when ever I need to and charge it with my Lipo charger instead of the big bulky charger it came with. 

So here's how to do it. 

Step 1 - Battery Selection.

You'll need to open up the battery that comes out of the handle of your drill and have a look (or measure with a multimeter) at much much voltage the battery supplies. Then you can buy a lipo to match. In my case this was a four cell 1.3 amp hours battery by Turnigy. Its also Important to take into account what the maximum discharge rate that battery will be subjected to is and make sure you get a battery that can handle that. I'm not exactly sure what that is for my drill so i got this 45-90 C discharge batter from HobbyKing for $13.50. The final thing to consider is a battery that will fit in your drill's battery casing. Don't get one too big or it won't fit and you'll be up a certain creek. 

Step 2 - Solder up the connectors 

Once you've got your battery ready to go you'll need to solder the connectors from the battery casing to a plug that will match what ever kind of battery plug you use. I use deans so that what I've connected here. You can work out which is the positive and which is the negative terminal by looking at the old battery you've taken out and seeing how it was connected. 

 

Step 3 - Insert Battery
Once you've got your connectors soldered up you can put your battery in side, plug it in and put the whole thing back in the drill. One mod you could do which I didn't, was to solder another battery connectors outside your battery casing so you can charge it with out taking it out of its case. I simply unscrew the case and take the battery out when I want to charge it. I've actually got two so I just swap the battery over and put a new one in while I charge the flat one.

 

Japan

I just arrived home from a two week trip to Japan for the purposes of site seeing and snow sports. Over the next few months there will be photos appearing on Flickr of my travels. However in the mean time I thought I'd make a little post about my thoughts of Japan and recommendations about where to go and what to see when you are there.

Firstly it would seem that all those website who say its a good idea to book ahead when you visit Japan are in fact correct. We didn't. Well we already had our first week of accommodation booked in Niseko where we went skiing however we didn't book much else and we kind of had to take what we could find, which wasn't always easy. That being said, if you are going to wing it as we did, there are a lot of things that will help you, like some great websites such as Booking.com, WiFi everywhere you can imagine and a very awesome Japanese Rail network that will get you everywhere, quickly.

One word about booking.com. While its true they won't charge you to use their website they will charge the hotel you are booking with and in the case of the smaller ones, they'll probably jack the price up to match. So if you can speak Japanese or get lucky enough to phone a place that speaks English, simply get the number of booking.com and phone then for you reservation instead of using the website, you might save a few hundred Yen.

Japan rail is an amazing organisation and moves a truly impressive amount of people around every day with out incident. They are also the most punctual institution I've ever dealt with. So if you are traveling to Japan and are going to be using them, and I'd recommend it, then you should probably get your self a JR Rail Pass.

Of the many reasons to use JR, one of my favorites is the opportunity to ride on the mighty Shinkansen or bullet trains. It is truly incredible how fast, smooth and reliable these trains are. If you do want to go on the fastest one of all, you'll need to travel express from Utsunomiya to Morioka (or the other way) on the Hyabusa Shinkansen which will get up to 320 km/h.

Japan is a beautiful and diverse place. In our travels, my friends and I went from Niseko to Sapporo to Hakodate up in Hokkiado (north island) and on down though Honshu (middle island) stopping at Nikko, Nagoya, Kyoto, Mishima and Tokyo. My picks of the places we went would have to be Kyoto for its shrines and temples, Nagoya for its winter lights festival and Niseko for its beautiful scenery and amazing food.

Messing with the internal databases of Android Apps in Windows

OK, first things first. You'll need a rooted Android Phone for this. If you haven't rooted this here's a link to get you started. The Unlockr

So now that you've got a rooted phone (with some kind of super user app, I user SuperSU ) have you ever thought it would be fun to change things about apps which you can't other wise. Cheating at games comes to mind, but there's loads of other things you could do by playing with the databases which back Android Apps. This is also very useful if you are developing an app which uses a database and you want to have a look at whats in your database. The other thing you'll need before we start is the Android Debugging Bridge which you can get from the Android Developer web page as part of the SDK with some help on it here

So lets go.....

Step 1.

Open up a terminal and navigate to the install directory you installed the android SDK to. 

On my machine it looks like this.

C:\Users\Rob\AppData\Local\Android\android-studio\sdk\platform-tools>

Step 2.

Run the following command to make sure you're device is listed

C:\Users\Rob\AppData\Local\Android\android-studio\sdk\platform-tools>adb devices
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
List of devices attached
003f7cf0df1ab41d        device

This will show you your device connected to the ADB. If you don't see any devices here you might want to check the Android Developer pages for some help

Step 3.

Run the following command.

C:\Users\Rob\AppData\Local\Android\android-studio\sdk\platform-tools>adb shell
shell@mako:/ $

Now your connected to the Lunix terminal of your device. So far so good but we need to give your selves super user permissions to do this.


Step 4.

Simply issue the following command and the accept the prompt (if the super user app your using issues one) on the device.

shell@mako:/ $ su
su
root@mako:/ #

Step 5.

Now that you're a super user you can do pretty much anything, but remember, with great power comes...well you know.

Anyway now you'll want to change down a couple of levels as follows and list the directory contents.

root@mako:/ # cd data/data/
cd data/data/
root@mako:/data/data # ls
ls
at.mroland.android.apps.nfctaginfo
com.adobe.air
com.adobe.reader
com.android.backupconfirm
com.android.bluetooth
com.android.browser.provider
com.android.calculator2
com.android.cellbroadcastreceiver
com.android.certinstaller
com.android.chrome
com.android.contacts
com.android.defcontainer
com.android.documentsui
...

Step 6.

What you'll see here is a lost of pretty much all the apps you've got installed, including the out of the box ones. This is pretty much your "Program Files" directory on Android. Now pick an app you'd like to mess with and change in to its directory and then on down into its database directory. I'm going to change into the directory of the popular Cycling app Strava. Note that not all apps have a database directory so if not there isn't much you can do. Well you can edit their properties files and other files you find there.

root@mako:/data/data # cd com.strava/databases/
cd com.strava/databases/
root@mako:/data/data/com.strava/databases # ls
ls
google_analytics.db
google_analytics.db-journal
mixpanel
mixpanel-journal
strava
strava-journal
root@mako:/data/data/com.strava/databases #

Step 7.

Now that you know where the database is located for your app change but up to the root directory and see if you have sqlite3 installed bu doing the following.

root@mako:/data/data/com.strava/databases # cd ../../../../
cd ../../../../
root@mako:/ # sqlite3
sqlite3
SQLite version 3.7.16 2013-03-18 11:39:23 [www.ptsoft.org] [www.ptdave.com]
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite>

Step 8.

As you can see I've got sqlite3 installed. If you don't, have no fear just go and grab the installer here and install it and then try it again.

Once your ready to open your first database simply do the following.

root@mako:/ # sqlite3 /data/data/com.strava/databases/strava
sqlite3 /data/data/com.strava/databases/strava
SQLite version 3.7.16 2013-03-18 11:39:23 [www.ptsoft.org] [www.ptdave.com]
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite>

Step 9.

Well there you have it. Get your SQL on and have fun. A couple of handy commands for sqlite3 are .exit to quit and .tables to show you all the tables in the database. Once you've got all them you can simply select or modify their data in anyway you like. Have fun.

Note: to exit simply type .exit to quite sqlite, then exit to quite super user, then exist to quit adb and finally exit to quit the command prompt.