2nd K9 Continued

After a little work in the garage, I'm begining to see what I need to do to knock this body shell into shape. A little strengthening here and there etc and it should be good to go.

It looks much better with the excess fibreglass cut off.

The second control panel,

Second Head

The Idea is to cut a hole in K9's head to accomodate a speaker, but as I don't want to do major changes to K9 which I cannot easily reverse I thought it best to make a whole new head to work on.

and so it begins

The Gel coat took an exceptionally long time to cure, so I've ordered some fresh catalyst, but in the mean time I removed the part from the mould.

And did a little tiding up.

Now I'll have to wait for the new catalyst to arrive so progress is halted.

 

The head ready to come out of the mould.

Next the control panel and side panel. The side panel may take a little longer as I don’t have a mould for the side panel. The panel I have on K9-1 is plywood that is impregnated with resin and spray, but I can perhaps use it as a pattern.

K9 - head upgrades

Now progress on the control panel is coming to fruition, I need to look at wiring the I2C bus into the head. However when I came to look at the wiring, I've realised that a bit of rework is in order.

The visor Arduino Mega is mounted nicely, but the Arduinos for the radar ears and laser is very poor so needs sorting out before I add the extra wiring.

Spaghetti junction

After much work I've created an assembly for the 2 Arduino Nanos that control the ears and the laser, as well as a DC-DC converter an a signals distribution board. It is alittle tighter than I anticipated, but it is a removable module. 

Also it incorporates the I2C bus, so eventually they will take commands from the Raspberry pi, and not ust the control panel switches

Progress

K9 - Control Panel

This weekend I'm changing the button signals to I2C signals. I was disapointed to find that the Raspberry pi could only be a master so will not respond to I2C signal. It will only request data from slaves.

Pre - conversion pic

Progress is slow but getting there.

Nano support and some wiring

Arduino Nano One to control the LED's in the switches. Arduino Nano 2 to detect button pushes and send via the I2C bus. Arduino Nano 3 & 4 to control the LED matrix in 2 red displays. Only One LED matrix fitted and half wired.
Power and signals to the control panel through the 9 pin D-type connector.

Red Wedge Down

Whilst reviewing Red Wedge with a view to letting the Young Roboteers a go driving a small combat robot, I realised that one of the wheels was seized. After stripping the gearbox, I found that many of the gears had broken teeth which were jamming the gearbox.

So I need a replacement if Red wedge is to fight again. This is an old motor from an cheep drill I think it was B&Q we got them from. This was before the moder LiPo batter drills.

K9 - Is there anybody home?

ROS on my pi

It was fun to build a K9, but there is something missing to my canine companion. That is intelligence!

With this in mind I'm investigating the Robot Operating System or ROS for short.

It has been painful getting it onto the Raspberry pi, as the instructions are not quite as complete as you would like and my knowledge of the raspberry pi is a little sketchy. Consequently it has taken about a week of the Christmas break to get it installed.

However, it is now on the pi (and backed up) and I've started on the actual ROS tutorials :)

So far I've got as far as driving around a simulated turtle, as above

K9 Diaries - 2017 Mini Maker Faire Derby

K9 had another outing, this time at the Derby Mini Maker Faire, at the Silk Mill Museum on the 28th of October 2017 and look who he snapped on his K9 cam.

Dr Lucy Rogers

Improvements since Whooverville are the tail mechanism and the visor lights, although there were some malfunctions with the visor lights, as some of them wer not working, but this turned out to be just some poor connections.

I usesd an Arduino Mega 2560 for the visor control, mostly because of the large number of I/O's available, and there is a connection to one of the switches on the control panel to change from all on mode to a Knight Rider function.

Below is the mounting of the Arduino Mega 2560, mounted on a plate, which slides into features which are bonded to the inside of the head, then a retaining clip holds it in. I just need to figure out the cable routing.

Arduino Mega 2560 mounted

I've since fixed and added a random function

The tail now also wags at the push of a button on the control panel. This is controlled by an Arduino Nano, with a simple sequence to a servo.

We  ordered a Tom Baker cut-out to pose next to K9, who was well received with many people having their photos taken with K9 & Tom and lots of  children had fun pushing the buttons.

I'm still working on improvements such as fitting the laser extender mechanism and the Software for the visor lights, which needs changing to an inturrept rather than waiting for the loop to finish before recognising the input.

K9 Diaries - Development

ADC and level shifter

The first job is battery monitoring, as I don't know how long to expect the batteries to last then it is important to have some feedback from them to determine their charge level. The Batteries at 12.4V each and the minimum discharge level is 9V.
A simple voltage dividing pair of resistors and a connection to the Raspberry Pi via the I2C bus has been made. The Adafruit library and example program has been added to the Pi and tested, so I just have to wire the inputs to the batteries and adjust the program to monitior the voltage and calibrate the output to reflect the true voltage.

K9 Diaries - Motor Controller Issues.

K9 wiring

The inside on K9 are pretty straight forward. There is a Sabertooth motor controller. Its a 2x32 generation 3 controller, which means it has a USB interface to an application called DEscribe. With this you can monitor the inputs and outputs, which is handy. You can also specify the battery chemistry and many other bits and pieces.

I've just fixed the motor controller location between the drive wheels, so it is no longer on top of the batteries.

The other upgrade is fitting the Arduino Nano to control the tail servo. Again a little more thought  when I was designing the wag mechanism, so there was somewhere to mount it, but ti-wraps to the rescue, and a mount from the walker robot and it is secure. The next iteration will have a dedicate mount point. The point is the tail which now wags!

I decided to fit the 4 switch elements in the control panel, and wire them, and the I2C pins of the control panel Nano to the D-type connector which I've used as an interconnect. The I2C pins are fur future use / development. One of the switches can now be used to activate the wagging.

The switches are a low level implementation but a first step in getting things going.

K9 Diaries - Whooverville 9 2017

Success, K9 was completed for Whooverville 9 at Derby Quad, his first ever outing, all the hard work was well worth it seeing the smiles on the faces of people that met him. I lost count of the number of people that complimented me on the build and a few even asked to buy him, more than my life is worth to sell him though, Debs finally has a dog and she's not parting with him lol!

I had to have a go in the TARDIS :)  K9's control panel looped through a sequence of K9 and then 200 random selections of the lights.

The screen was fully operational, although we didn't want to infringe any copyrights by playing Dr who episodes at a public event, but as well as photo capabilities, K9 has movie playing abilities on his screen via his built Raspberry Pi.

His antenna ears operated continuously for the whole event, as did his control panel, and we had his camera taking photos every 10 seconds to record what he could see during the day.

Although we did have to cut out a fair number of shots of peoples trousers. Next time we'll have a perimeter around so we get see more people and less of their bags and behinds, we'll also encourage the people to smile for K9's Timey Wimey Cam as Debs has christened it. Below is a video Debs made from the images that K9 took.

Sadly his drive broke down, some issue with the motor control / receiver which needs to be investigated but all in all it was a brilliant experience,really good to see the smiles on the faces of people young and old who wanted to meet K9 and have their photo taken with him. We're already looking forward to Whooverville 10, see you there!