timcorrigan.com

Raspberry Pi Tracked Robot – streaming video and text to speech

Tim Corrigan — Mon, 20 May 2013 12:41:57 +0000

For phase two of my Raspberry Pi based robot (now christened ‘Roger’) I decided to add a camera for remote video based control and a speaker so that it can talk. The camera is a Logitech C200 plugged into one of the Pi’s usb ports and the speaker is the excellent X-Mi X Mini 2 plugged into the Pi’s audio output.

Text to Speech

Easily handled by the Pi. I came across this article with a few methods of achieving text to speech on the Pi and went with the Festival option. At the moment I’m happy with it sounding very robot like! I’m calling it from Python with something like the following: os.system(‘echo “‘ + text + ‘” | festival –tts’) where text is a variable containing the words to speak.

I also added the ability to play a wav file as a way to add solme fun sound effects (like a lorry start up noise when the robot starts up and a siren for waking people up). This is done with aplay – full instructions here. Again called from python with something like: os.system(‘aplay /home/pi/robot/diesel_lorry.wav &’).

Streaming Video

For streaming video I’m using Motion – here are some quick setup instructions for the Pi. The Logitech C200 works well out of the box with the Pi. I did try a C310 first but there was significantly more delay on the video stream (presumably because of the higher source resolution). If choosing a webcam (or any other peripheral) to get for your Pi check out this list of verified peripherals first. Obviously there is tons more I can do with Motion like detecting and responding to actual motion but for a first cut of streaming video to a browser for remote control robot operation this setup works well.

HTTP API

To control the robot via web browser I’m using Webiopi. I have a Python script defining my Webiopi ‘macros’ and a custom HTML page using their Javascript API to create a page with buttons and a text box for entering speech. Complete code listings for these at the end of the post.

Demo of the robots capabilities so far

Code Listings


#webrobot.py
 
import webiopi
import time
import sys
import os
import urllib
from raspirobotboard import *

webiopi.setDebug()
robot = RaspiRobot()

def setup():
    webiopi.debug("Setup")
    flash_lights()
    flash_lights()
    os.system('amixer cset numid=3 1')
    os.system('aplay /home/pi/robot/diesel_lorry.wav &')

def destroy():
    webiopi.debug("Destroy")
    flash_lights()
    flash_lights()
    flash_lights()
    flash_lights()

@webiopi.macro
def speak(text):
    # decode url encoded parameters
    text = urllib.parse.unquote(text)
    webiopi.debug("Speaking: %s" % (text))
    os.system('echo "' + text + '" | festival --tts')

@webiopi.macro
def forward():
    robot.reverse()

@webiopi.macro
def reverse():
    robot.forward()

@webiopi.macro
def stop():
    robot.stop()

@webiopi.macro
def left():
	# turning in small increments, helps with slightly delayed response on a mobile
    robot.left(0.15) 

@webiopi.macro
def right():
    robot.right(0.15)

@webiopi.macro
def lights_on():
    robot.set_oc1(1)

@webiopi.macro
def lights_off():
    robot.set_oc1(0)

def flash_lights():
    lights_on()
    webiopi.sleep(0.25)
    lights_off()
    webiopi.sleep(0.25)






        
        
        
        
        


    
        Hello. My name is Roger. Nice to meet you.

Raspberry Pi Tracked Robot – LED headlight

Tim Corrigan — Fri, 17 May 2013 18:15:23 +0000

Sorting out some boxes the other day I came across an LED keyring torch given to me by friend Michael. Whilst this was an awesome torch, after a while the button became unusable so it has fallen out of use. So I had the idea to use the LED as a headlight for our Raspberry Pi based robot!

Here are the steps:

1. Dismantle LED torch. I was surprised how little there was in this one. Just two 3V batteries stacked on top of one another and the LED mounted in such a way as the switch makes it contact the batteries. No other circuitry or wiring.

2. Cut up protective plastic that often covers a UK mains socket when you get a new appliance. These make great LED bulb holders!

3. Solder the LED to some hookup wire and connect to an output on your controller. I’m using one of the OC outputs on the Raspirobot board. NB: You may need to put a protective resistor in depending on the LED you use.

4. Test. Setting the output to 1 (high) turns the LED on and to 0 turns it off.

5. Turn off the house lights and take your Robot exploring in the dark!

Thanks again for the awesome torch Michael – made a great torch and now make a great robot headlight.

Afan MTB 2013

Tim Corrigan — Mon, 29 Apr 2013 10:11:26 +0000

After a year off due to non cycling life getting in the way – Team A just made a return to the Afan Valley in South Wales and as usual we had a fair share of fun and drama.

Arriving Friday night and heading straight to the pub regulars Andy, Mark S and myself welcomed Mark F and Tom to the team, sharing stories of breakdowns, accidents and broken riders from previous trips.

We predicted Andy having his usual accident on the first climb and Mark S having his usual mechanical breakdown – supported by Mark’s admission that he’d had his rear suspension ‘temporarily fixed’ by a shop with them predicting it would last ‘a day of riding if he is lucky’!

We also decided on doing the full W2 route on the Saturday. This route is made up by combining the Wall and Whites Level into one big ride (the combination being graded a black route)…

The usual Whites level climb out of the valley was closed and we took the diversion ascending what is normally the final descent. This was very technical climbing indeed but we made it in one piece and after the first section things got easier. After the first descent it was along the high level track over to the Wall, though we did manage to miss a sign and add in a whole extra loop of fire track!

After some more great downhill we came across the new bike park (aka jumps). Riding over for ‘just a quick look’ Mark S had a go on some small jumps and looked so comfortable and smooth I though I’d have a little go as well… and came flying off on the second jump and landed in a heap! Not as easy as Mark made it look then! (it’s all his fault obviously) With a very swollen left hand from my fall I could no longer grip the handle bar so any more technical downhill was ruled out for me. After Mark F bandaged my wounds up (from here on the team A medic) I made it down the hill and had to call it a day returning via the flat valley floor. Tom jumped on this chance to tap out as well and joined me while the others went on to complete the full W2 route. Well Andy, I guess I had to take my turn at being the injured one but I’m sure you’ll be back on form another year

A prominent talking point of this trip were Strava stats! If you’ve not heard about Strava it’s a mobile App that uses your GPS not only to map your rides but also to record your stats including personal records on sections and comparisons with friends and other riders… and it’s addictive. With Tom, Andy and I all training for the same road tour in June and all fairly close on distance ridden and elevation gained in 2013 to date, the competitiveness reached a peak for this weekend with most titles up for grabs.

Sunday had the 2 Mark’s and Andy head off around Whites again – they can’t get enough of that route! Tom and I planned a very sedate ‘Team B’ style ride along the valley floor – however, setting off to explore we ended up climbing out of the valley along some fire track and we were delighted to see from a sign that we’d actually picked up the route of the Skyline! The Skyline is less technical (on average) but a much longer route than the others and though we’ve done it once we tend to avoid it because the others offer riding that differs more from what we can get at home. However it was perfect for me (riding one handed) and Tom (with tired legs) and we made it to the Windmill area at the top of the W2 climb and came down a mixture of more fire track and bridleways. The ride in the end wasn’t that far off (in the all important Strava stats) from the other groups ride so I’ve nominated it the Team A- Afan route (and I’ve a feeling it will be ridden again in future!).

So the winner on the Strava stats? Andy is a clear winner on both elevation gained and distance ridden – but Tom and I managed to keep him well within reach. A great weekend – and as soon as my hand heals I’m going to be back on my bike trying to oust Andy from the top of the stats!

UPDATE 04/05/2013: By popular demand a pic of the swollen hand (much improved since then I’d add!):

Raspberry Pi Tracked Robot Phase 1

Tim Corrigan — Thu, 25 Apr 2013 20:00:53 +0000

So I decided it was time to get myself a Raspberry Pi. I have a few ideas for projects I want to do with it but to start I thought my 7 year old step son would both enjoy and learn from helping me build a robot. (ok I just really wanted to make a robot – I don’t understand why anyone wouldn’t want to make a robot!)

So phase 1 is up and running. It consists of:

Raspberry Pi +accessories. I got a case, mini keyboard, mouse and monitor but none of these are essential – you can setup with any keyboard/tv/monitor and then continue via ssh. I already had SD cards and a suitable power supply.

RaspiRobot board - I did need to solder this myself but even for someone who hasn’t soldered since I was a teenager it was pretty easy. And it let me feel like I actually built something rather than just plugged a few parts together

Arexx RP 5 Chasis - if I’m going to build a robot it’s going to be on a tank chassis!

Edimax EW-7811UN Wireless Adapter

I’m currently connecting via ssh over wifi and just issuing movement commands via the Python API written for the RaspiRobot board.

Here are the steps to get to this point once you have the above items:

- Setup SD card and PI

- Build RaspiRobot board

- Enable SSH

- Setup Wifi

- Connect RaspiRobot board to the PI, and fit (ok blue-tack) to the chassis. I soldered on a power connector I had lying around to connect the battery holder that came with the chassis to the RaspiRobot board. The battery holder slots neatly into the base of the chassis under the Pi. I also added a crocodile clip as a makeshift heat sink on the voltage regulator (I’m not sure if I really need this but it was getting extremely hot).

- Run through the tutorial for the RaspiRobot board to start issuing LED and movement commands from Python!

And here is the functioning Robot at the end of Phase 1.

The next step is to write some proper control programs for it and then think about adding remote control by either Mobile App of Wii remote. And there are of course lots of other possibilities like adding sensors, a camera etc. etc.

Very happy with my robot so far – can’t wait to add more to it!

House renovation phase 1

Tim Corrigan — Sat, 16 Mar 2013 13:54:10 +0000

So we moved into our first ‘proper house’ at the end of 2012.

I’ve since been bombarding people with photos on my phone of various bits of renovation – much like someone who turns up with an armful of photo albums of family holiday pics! So to document some of the first phase of renovations we’ve done, here are some before and after pics. This is very much phase 1, covering the first 2 months of sorting out the worst things and getting everything functional.

Although this is obviously a departure from my normal blogging topics, there is one distinct cycling related advantage to the new place. A garage big enough to store both my bikes (and more) – so for the first time I’m able to live somewhere with both my road bike and mountain bike available at the same time. Hooray!

Bedroom – bye bye gold and pink!

Bedroom door and wardrobe

Kitchen

Dining room

Bathroom

And finally a gallery of images of moving in day and work going on in the early stages:

Training with Strava

Tim Corrigan — Sun, 24 Feb 2013 08:52:52 +0000

I’ve started training for a big cycling trip this year (more on that in a future post!). When one of my fellow riders emailed to say I should get on Strava I thought oh no – not another GPS mapping app – quite happy with Everytrail thank you. However – after a few rides I’m converted. The App is really easy to use and if you have friends that ride you get to see all their rides and compare each others trainers. And I think this is going to be super motivating!

Here’s the ride I did yesterday courtesy of my new favourite mapping AND social networking App Strava:

Remote working: the pitfalls of Skype

Tim Corrigan — Wed, 07 Nov 2012 19:45:17 +0000

I was searching for something in my Skype history today and caught myself laughing at the bizarre mixture of banalities, repetitiveness, dreadful spelling and total screw ups. So here are a few choice excerpts – this is probably only going to interest you if you work remotely or are a programming nerd, preferably both. But if you are – this might ring a few bells…

I’ve anonymized as I’m sure my Skype correspondents don’t expect their chat to get published – but other than that it’s true to the original, spelling mistakes and all.

Idle status?

Tim:will put it in email…
James: Yes – no probs.
James: Whats happening?
Tim: just sent an email…
James: LOL OK
…

Security breach

Tim: wwineS02lkl
Rob: wrong window?
Tim: wwinlol
Rob: Security breach
Tim: sorry – that’s my Ubuntu VM password
Rob: LOL
Rob: Delete chat history
…

Remote server restarts

Chris: Do you want be to stop the web server now?
Tim: ok yes please
Chris: Ok its stopped
Tim: thanks
Tim: ok – can you start server again then please?
Chris: Started
Tim: ok. and now stop please
Chris: Stopped
Tim : thanks
Tim: k can you restart the server please?
Chris: Ok, started
Tim : thanks
Tim: ok and stop again
Chris: Stopped
Tim: cool fixed
…

Crystal Ball

steve: Powering up my crystal ball
Tim: I think the check box is clear – the downside is that it will be hard to fit a descriptive label in (applies to button as well)
Tim: you should go to the crystal maze
steve: lots of crystals there
Tim: ok – more changes pushed to github. I think I’ve addressed everything at least in some way.
steve: checbox thing is pretty good!
…

Coding/Life mashup

duncan: ok laundry + coffee + js scolling — will ping before 11!
…

Responsive Design

dave: but ZOMG narrow the browser
dave: responsive design!
Tim: yeah already done
Tim: very nice
dave: wait are you the kind of SAD NERD who automatically narrows browser windows just to see? o_O
Tim: yeah wonder where I got that from
…

Home working environment

scott: I am experimenting with standing rather than sitting at work cos my back has been bad recently
Tim: wow
Tim: sounds bad
scott: yeah I am such a hipster — standing desk
scott: all the web 3.0 startups have them
scott: get with the programme
Tim: web 3.0? I’m web 4.0
…

Browser compatibility

Tim: The IE error could be because of the embed?& (shouldn’t have the & in this case) or perhaps so other problem with encoding of that url
Ben: we’ll work on the IE 8 problem.
Tim: to be clear – I’ve tested in latest Firefox, latest Chrome and IE9 (sorry not 8) – they should test in other as well – especially older IE versions
Ben: So it’s IE9, not 8, that you tested?
Ben: Thanks, Tim.
Tim: yes. IE9 for sure.
…

Nerd Hipness

scott: I am off to Bletchley for Over the Air tomorrow
Tim: oo nice
scott: now who’s the loser schmooser not-so-hipster?
Tim: I’m launching an Android app tomorrow!
dave: ooh
scott: I have been working with PHP CodeIgniter framework (2 weeks ago) and now PHP Cake framework
Tim: hmm I’n not sure that gets you any points
…

Your own Skype (or GChat) excerpts are welcome in the comments.

SW Coast Path Sidmouth to Abbotsbury

Tim Corrigan — Thu, 25 Oct 2012 21:10:13 +0000

This year I’ve managed to add a new leg to my South West Coast Path record with my friend Mike. Over the course of two separate weekends we managed to cover the path from Sidmouth in Devon to Abbotsbury in Dorset. This section features some challenging hills including Golden Cap, the highest point on the whole trail.

This being Devon and Dorset and England though it would have been rude not to have sampled a fair few English breakfasts, ice creams, pub meals, cream teas and beers along the way! Two very enjoyable weekends indeed!

Some pictures and a rough route map follow (map isn’t true GPS data this time – but it’s enough to give you an idea). For more on my previous excursion onto the SW Coast path you probably want to check out the other Michael’s account

SW Coast Path Sidmouth to Abbotsbury at EveryTrail

Tour du Mont Blanc 2012

Tim Corrigan — Sun, 01 Jul 2012 13:16:17 +0000

Michael, Alex, Mark and I set out to walk the TMB – a 170km long route circumnavigating Mont Blanc in the Alps with around 10,000m of ascent and descent over 10 days.

We were at the very beginning of the season, staying in several refuges the day they opened for the first time in the year. Being so early, the trail was relatively quiet but we still met several others doing the same trip or some portion of it.

We stayed in a combination of B&Bs, hotels and refuge accomodation – the refuges including the absolutely delightful Refugio Bonatti (nicer than many hotels I’ve stayed in) and the Refugio Elisabetta. The later would have probably been pretty nice except that… Michael lept to take the first shower which he managed… just! After that no more running water in the entire refuge for the duration of our stay (one 15cmx15cm wipe was my entire showering experience that night!)

Other highlights:

Sliding down the snow slopes in the passes (see video below)
Eating as much as we liked (and then some) for 10 days
Some challenging river crossings (I removed boots for just 1 to wade)
in 10 days of walking only 2 hours of rain and many glorious sunny days
The variety of views as we changed altitude and country (France -> Italy -> Switzerland -> France)

Sadly, Alex didn’t make it the whole way round due to a lot of knee pain. I believe that descending presents a bigger challenge to those not used to this kind of walking for exactly this reason. Alex was the only one who’d not done a long distance trail before (though we all felt knee pain during the first few days) so I guess the moral of the story is – the TMB probably isn’t an ideal first multi day hike. Nonetheless hopefully he’ll have got a taste of the truly stunning views and sense of achievement and will keep up the hiking!

Here are a selection of photos from the trip:

… and a 2 minute video, giving a small glimpse into what it was like on our Tour du Mont Blanc. I think Mark’s line “STOP taking pictures and walk… oh God” will be one I’ll remember for some time!

In summary – the views were stunning, the walking challenging but satisfying and the company fantastic so all in all it was certainly the best walking trip I’ve ever been on and right up there in the top handful of trips of any kind. Highly recommended once you have 1 or 2 slightly flatter long distance walking trails under your belt!

Tour du Mont Blanc day 10 update

Tim Corrigan — Sat, 23 Jun 2012 13:46:17 +0000

We have finally completed our Tour du Mont Blanc and have arrived in Chamonix.

Over the last few days we’ve done a huge amount of ascending and descending, have seen many ibex and enjoyed the part of the route with many ladders. Some more photos before a full write up when I get home…