Inspecto Roboto: A dirty robot, just how we like it.

Our resident electronics expert, Andrew has been busy in the man cave this weekend. After reporting some dampness inside his house he decided to take matters into his own hands. The outcome: ‘Inspecto Roboto’! Andrew has pulled apart his racing drone and a few other bits and pieces to hack together a pretty sweet inspection robot for under the house. Check out his build below. And don’t forget to check out some of his other cool projects on his website.

 

Check out the Video in HD here.


Some of the Key components

  • Lynx motion Tri-Tracks chassis
  • 2 x 12V geared DC motors
  • LM298 motor controller drivers

  • 4s LiPo battery pack
  • LED light bar
  • Servos

  • Taranis hobby RC transmitter
  • FRsky receiver
  • Teensy 3.2



The 'Inspecto Roboto' - A confined space inspection robot.

My house has a bit of a moisture problem and I wanted to inspect the floor crawl space to see if there was an obvious fault. It is a horrible cramped environment that whilst I can just wiggle inside the rat carcass at the door confirmed my doubts about venturing any further. So I decided to tackle the problem with robotics!

This was a weekend build and whilst I just used parts lying around I had a lot of nice spares and old projects to work with. Essentially this was a hybrid system using parts from an old racing drone & a lynx motion robotics kit.

Locomotion was a lynx motion Tri-Tracks chassis. It has a nice set of rubberized Tracks as well as an acrylic frame, two 12V geared DC motors and other associated hardware. A basic LM298 motor controller drives each set of tracks from a 4s LiPo battery pack tucked inside. The camera system was from an old racing drone with an FPV display to make driving it around easier. The servo allows for tilting the camera up, panning is just turning the robot on the spot. Finally, a large LED light bar from a vehicle was installed up against the front with some additional acrylic pieces to act as bushes and help retain it in place. The light is controlled via a relay as it is convenient to switch it off when unrequired as it draws about 12W.

The controller was a Taranis hobby RC transmitter paired with an FRsky receiver and a teensy 3.2. The teensy decodes the signals & operates the motors, lights & servo. I have written about using these transmitters with microcontrollers before (Here) and they are a great option for long-range and reliable communication which xBees & other serial radios often struggle with.

The whole system was a bit of a hack but as someone who often spends forever ‘gilding the lily’ on a project until they grow bored of it and don’t finish it, this was a fun and pleasant change.


Andrew Van Dam

An electronics expert based in Australia dedicated to creating great tools for the maker community.


Controlling GPIO with your travel router

The GL-inet range of travel routers are sold with the understanding that we can use them as more than just a router. The idea of being able to interconnect them with everyday items is very appealing. They call this the ‘internet of things’. So the curiosity got the better of me and decided to see if we could do the most basic of tasks. Switch a relay module!

Sounds simple, and sure enough, once we did a bit of research, it was. Keep reading to find out the basics of setting up your GL router to trigger a relay module using the built-in GPIO pins. If the config stuff is a bit boring for you, skip directly to the working video below!


Some light reading/research

  • http://wiki.openwrt.org/doc/hardware/port.gpio (Understand how OpenWrt and GPIO works)
  • You will require a GL-inet router. We used a GL-MiFi and a GL-AR150
  • You will also require a 5V relay and some headers/jumpers to connect
  • A soldering iron


Pinouts (For reference)


Solder some header pins to your device

First of all, you will need to decide which what sort of relay you are going to use and which pins to utilize. I only had 5V relay spare, thus I need to grab 5v from the board and a signal from a GPIO pin. Connect the 5V + and GND up and the signal/GPIO.

The gallery above has the pinouts for the GL-MiFi and the AR-150. Check these to determine the pins you want to use.


Add some config to the router

SSH into your router, locate the file: /etc/rc.local – Add the config below. Remember to set the pin number to the GPIO you intend to use. This will enable ‘output’ on that particular GPIO. Also, make sure you insert before ‘exit 0’


Add some config to the router

Shutdown your router. Connect up your relay to the 5V source, and the GPIO you selected in the rc.local config. Power back on your router, SSH back in and run the commands below. “1” will turn the relay on, and “0” should change the state so that it is off.



REVIEW: GL-MiFi 4G Smart Travel Router

If like me, you travel a lot, then having a solid travel router that allows me to work on the move securely and with anonymity is a necessity. The GL-MiFi router has proven to be a solid and reliable unit that has some perks that other travel routers cannot match. This review will cover some of the pros and cons. However, saying that, the Pros far outweigh the cons!

The GL-MiFi is powered by an Atheros AR9331 processor, is small, lightweight and contains a slot for various PCIe 3G or 4G modules. Combine that with 150Mbps Wi-Fi and you have yourself a very powerful little device. The GL-Mifi runs an embedded OpenWrt system, is extremely extendable via hardware and software. It can be used in mobile applications, industrial, commercial or at home.


Pros

  • 3G/4G capable
  • Built in Battery for mobile use
  • OpenVPN client capable
  • Excellent portability
  • 6-8hrs uptime on battery

Cons

  • When trying to charge the battery, router turns on.
  • GL-inet frontend software can be clunky at times.
  • Sim card can easily be inserted incorrectly.



Specifications

CPU  Atheros AR9331, @400MHz
Memory  DDR 64MB/ FLASH 16MB
Interfaces  1 WAN, 1LAN, 1 USB2.0, 1 micro USB (power), SIM card slot, MicroSD card slot, Antenna SMA mount holes
Frequency  2.4GHz
Transmission rate  150Mbps
Tx power (maximum)  18dBm
Protocol  802.11 b/g/n
Power supply 5V/2A
Power consumption  <3W
Dimension, Weight 105*72*27mm, 170g


The Hardware

When you first get your hands on the router, you notice that the enclosure is very solid. (As you can tell, I have dropped this unit twice… and it still works!) Nothing about the physical form of this router says “cheap” or “made in China”, The quality is second to none. All clips, buttons, and panels feel as if they will last the distance. This gives me confidence, I was certainly not afraid to throw it in my backpack with all the other crap I carry around.


3G/4G Module(s)

One of the standout inclusions in this travel router is the modulized 3G/4G PCIe cards that can be included. We ordered the Quectel EC25-AU with the unit. The seamless integration of this module with the built-in WiFi means that we can share a 3G/4G connection with as many devices as we need to. The configuration is as easy as inserting a sim card and selecting the region and provider. The module connects very quickly, so long as you have a data plan you will have connectivity to the internet. Of all the GL-inet travel routers the GL-MiFi is the only one with integrated cellular. Sure the other travel routers can use a USB dongle and tether, but nothing beats the quality and reliability of these built-in modules. For more info on the Quectel 3G/4G modules check them out here.


The Software

The GL-MiFi runs an OpenWrt firmware with a custom front-end user interface for its users. I think the ‘vastness’ of the LuCi interface could be a bit daunting for some, so they decided to write a front-end graphical user interface (GUI) that is easier to use and understand. From a basic user point of view, I think they achieved this goal. However some of the more advanced tasks you still need to achieve from the LuCi interface.

The custom interface interacts with OpenWrt and at times can feel a little bit clunky. Firmware improvements are being rolled out all the time and in the few months I have had the unit, I can see that the GL-inet crew are developing this frontend and fixing bugs as they come up.


The Fun Stuff

By Far the coolest part of the GL-inet routers is the fact that they can operate as an OpenVPN client and a Tor router. (We will do a post soon on setting up as a Tor router.) However, for now, we are going to focus on the OpenVPN side of the device. The OpenVPN client can be used in two ways. Either connect to your own self-hosted VPN server or connect to one of the popular paid VPN services. The paid services allowing anonymity and safety of your data whilst traveling, or operate through your own self-hosted VPN for access back into your business or home network. A typical setup of the OpenVPN service through a paid provider can be found here. (The setup on this router is the same for the MiFi)

If you have a keen eye on the GL-inet routers then you might have also seen in the newest firmware an ‘OpenVPN server’ being rolled out in beta form. I am yet to have a play with this, however, it is exciting to see a device no bigger than a rich-mans wallet hosting its own VPN server.


What next?

So many cool things still yet to be achieved with this router. Here is my list, in no particular order, of the bits and pieces I want to achieve.

  • Solar power kit to run the MiFi indefinitely.
  • Run up the Tor firmware.
  • Look at Mesh firmware
  • 3G/4G VPN tunnels into other networks
  • Control relays from GPIO pins onboard.

If you have any thoughts on what else we could do here, let us know in the comments below. Very keen to get your thoughts!!!



Get access to your PI ZERO W without a keyboard, mouse or monitor

So you purchased a Raspberry Pi ZERO Wireless and like me, did not realize that you would have no way to actually access the small form factor computer, because it does not have any standard USB ports. You actually require an OTG cable to attach any peripherals to the PI ZERO… well I have a pretty easy fix for you. It involves building the SD card using ETCHER (As seen here) or check out the links below. Adding a config file for the built-in wireless (Assuming you have a PI ZER W) and turning on SSH. If you can achieve this you will then have unobstructed access to your new PI ZERO wireless.


What do you need?

  • PI ZERO W
  • Micro USB cable for power
  • 2.1A Power supply



Step 1. Setup SD card and download your image.

Download Raspbian Stretch Lite and use Etcher to get the image on your SD card. Grab your copy of Raspbian from here. The prerequisite steps here will walk you through Etcher. We will run the ‘Lite’ version on the PI ZERO because it does not have the processing power of the RPI3. Also, there is no point loading the GUI if we do not intend to use it for that purpose.

Note: Once etcher is complete, you may need to unplug/plug your SD card back in. Etcher may unmount the drive for you when it is finished. Also if windows spit up some errors asking to format the drive. Do not do it!


Step 2. Add two files to the PI ZERO SD card to allow wifi and ssh to connect on power up

The first thing we need to do is create two files in the root of the SD card. When you plug the SD card back into your computer, look for the drive called “boot”. You need to create two files. Once called “ssh” and another called “wpa_supplicant.conf” Please note that the file called ‘ssh’ has no file extension, and wpa_supplicant.conf has a file extension of ‘.conf’

The ‘ssh’ file can remain blank, we do not need to add any config to it. This will simply enable SSH on the PI ZERO. However the ‘wpa_supplicant.conf’ file will require us to copy and paste this config onto it.


Step 3. Put the SD card into your PI ZERO and power it up

Put the SD card into the PI ZERO and power up the PI. It will take approx 30sec to a minute for it to power up, get wifi connectivity, grab a DHCP address from your router and enable the SSH service. The problem we have now, however, is that we do not know the IP address of the PI ZERO for us to SSH into.

To find the IP address of the PI ZERO, we are now going to use ‘ANGRY IP’ Scanner on our local computer. You can see a run-down of how to find your RPI IP address here also.

If you don’t want to check out the link above. Then Go download angry IP and run it up. It is pretty easy to use and will ping every active device on your network to tell you if it is UP or DOWN. The hardest part is identifying the correct Pi on the network. If you are like me, you may have more than one.


Step 4. Now that we know the IP address of our PI ZERO, lets try SSH into it.

Open up ‘Putty’ and enter the IP address into the required field. Make sure the SSH radio button is selected. Generally, port 22 is suitable for SSH. (This is the default port.) Then click ‘Open’ at the bottom.

So long as the PI ZERO has wifi connectivity you should now be able to SSH into your PI. I would now start to update the build/packages and also look at changing the hostname so that it can be identified easier on the network.



Powering Ubiquiti links from 12v

So it seems that I can power a Ubiquiti Bullet and Rocket directly with DC 12v. In the past I have been chasing POE and wasting precious milli-watts converting 12V to POE standard (Usually 24v or 48v) then powering the devices.  A power saving can be made by connecting direct to 12V. If using a solar setup, the power savings can mean more up-time, and better use of your batteries. Some testing will follow this blog post. However in the interim, it seems pretty stable here in the workshop.


How to make your own cable for 12v power supply.

  • RJ-45
  • RJ-35 Crimp
  • Pliers
  • Box Cutter
  • Straight through Ethernet cable

In a nutshell, the Ubiquiti Bullets and Rockets grab power from 4 pins on a standard RJ-45 connector. In our case here in Australia (Blue/White-Blue) pins 4 & 5 will carry 12v+ and pins 7/8 12v-.


Prepare your cable

If you have the resources to cut up a straight-through cable, then go ahead and cut one end off. (Otherwise you will have to complete two terminations) Strip the cable back a bit to expose the pairs of wires. Identify the solid blue and Blue-White wires. These will be your 12V Positive injection points. Now identify the Solid Brown and Brown-White wires. This will be your 12V Negative injection point. From here identify the remaining cores and insert them into an RJ-45 housing.

  • PIN 1 – White-Orange
  • PIN 2 – Orange
  • PIN 3 – White-Green
  • PIN 6 – Green

Now crimp your RJ-45 and you are all done. The bare wires can be used in anyway to inject 12v. ie Barrel jack. I would use a fuse close to the source to protect your equipment. Also confirm the pinouts prior to plugging in. The last thing you want is to fry your Ubiquiti gear.


Or Don't hack up a cable and buy some injectors

If you want that more professional look, then you can always purchase a few of these injectors. Have a look at the specs though and make sure the power inputs are on pins 4/5 and 7/8. Let me know how your setup goes? I really need to do some testing on the longevity of this type of setup. My only concern is that the fluctuating 12v from batteries could damage the Ubiquiti gear over time. Maybe I need to look at a circuit to provide clean power.



The Scott Bonnar 45 Project

Have you ever just wanted to get the boys (and girls) away from the PS4 for a while? well I think I found the solution… My son and I decided to give the whole “reel mower restoration” thing a go. After a bit of searching I decided upon the ever popular Scott Bonnar/Rover Model 45. It seems you can still find many parts for these suckers as well as plenty of donor mowers also if required.

We searched the ever faithful GumTree for a semi cheap donor mower and came across an old chap down the road selling the exact one we were after. A 17″ reel mower with the Scott Bonnar 45 stickers all over it. The nice, but old green paint job and oil stained Briggs and Stratton engine has us in awe. I gave it a quick test cut on the lawns and we purchased it on the spot.

Without looking too close, we probably should have checked it a bit more thoroughly. It seems that these mowers have a bit of a problem with the horizontal supports for the engines. Over time the engine mount holes get cracks in them and this can spell disaster for any home restoration project. The good news for us however that after a complete strip of the engine we had zero cracks and the restoration was good to go.


Some History on the mower

Thanks to ‘Bonnar Bloke’ from the Outdoorking.com forums we were able to get this little piece of history on this particular model of Scott Bonnar 45 mower.

“Well that’s one of the early made “Eagle Farm” Scott Bonnar’s after Rover closed the Holland Street Thebarton Factory in Adelaide the previous year. Your mower was assembled in early (March) 1984 with the Engine being made on the 6th of December 1983 over in the US of A.”

“It’s a rather interesting example as the ID plate is of the first batch of green metal plates that doesn’t refer to Brisbane as the city of manufacture. The later ones do, before they changed to silver foil style ID stickers. Also this mower shows evidence that they had not commissioned their new state of the art “Powder Coating line” yet which introduced the Kermit Green coloured Rovers. So the Eagle Farm factory was still shooting Hammertone Enamel paint which was now a different colour than what was used in Adelaide (Apple Green)even though the 1984 Range of mowers brochure still showed the Apple Green colour as being current.”


Getting rid of the paint

So apparently back in the day powder coating was not a thing and the SB’s were painted with a Hammer-tone enamel paint. I can tell you that it is truly very stubborn to remove. Initially I used a sandblaster with the course garnet and it got rid of all the rust and crap. But the paint that was still good quality would not budge.

I then switched to the grinder with sanding pads, which worked pretty well. However all the small grooves proved to be a hassle with the grinder. The third method was to then use those wire brush attachments for the drill and after some time was able to bring the mower back to bare metal.


A new motor

The original Briggs and Stratton engine that came with the mower still runs, however it has seen its best days and I decided a retro fit was in order. Would you believe that you can get a direct replacement “Chonda” or Chinese Honda for $144 delivered? well you can’t really beat this and even if I get 5-6 years out of it I will be happy. The process of removing and replacing the engine is pretty straight forward. 4 mounting bolts, a throttle cable and thats about it.


Update - 29/11/17

So it has been a long time between drinks. Since I started the SB, I have moved workshops, got married and renovated some of the house. Also had a few other projects on the go recently. What I can say is that the SB is mostly stripped back and in primer. I still have parts everywhere, hopefully I’ll find some time to continue the build soon. Oh and I also purchased a “Daily” mower that has been keeping the lawn in good condition. It came with the original manuals! Check out the pics below for more details.


Work in progress

This post is a bit of a work in progress. I’ll keep updating it as we go with the resto. Wish us luck!