PICAXE handling GPS for robot boat

Dippy

Moderator
I'm sorry to hear of the boat's demise. Nice project, but to be honest, a huge 'ask' for such a small boat.

I find it difficult to believe that a canoeist grabbed the boat and single-handedly (maybe literally) paddled against tide/wind to sabotage the effort. Sounds like a rumour Chinese-Whispered into reality.

Anyway, good luck with the Mk2. The video I saw was a little blurry so I may have mis-viewed, but I reckon you may have to pay more attention to sealing as I don't think B&Q silicon will be good enough. The difference between a windy lake and the sea is enormous and that ignores seaweed and pirates :)
 

Robin Lovelock

Senior Member
Thanks Folks. Yes I agree - for every "conspiracy" there are a hundred "cock-ups" :) Great if anyone can provide an alternative explanation, but I cannot think of anything other than Snoopy was snatched at about 2pm and taken to near the Needles, then probably released, before he sailed onto the rocks and gave those last two position reports. If you look closely at his track (such as with google earth) you will see their sailing speed was about 1.5 knots and the slower speed after 2pm, and curved path, all makes sense for a boat simply being pointed towards The Needles - their visible landmark. At first I thought it might have been a fishing boat, trawler, or RIB - but they would have speeded up above that 1.5 knots, rather than take hours. A kayak was the obvious boat, but discussing this today, at Bray Lake, with a guy who should know - he did say a small - but slow - sailing dingy (e.g. a Topaz?) might have been less "hairy" but also no faster. He agreed that it sounded foolhardy - even for an expert sea kayaker - to go out in a 20mph wind, with the swell that can be expected. You may notice some extra pictures and "tweak" made today on that page. e.g. "caught" instead of "stolen" :)
While I remember - yesterday I got an email from a member of the French Team: they had their boat stolen, while it was on test sailing around an island, by a fisherwoman. She took it home for her children, but then owned up when she heard about it on the radio :)
Robin
www.gpss.co.uk/autop.htm
 

Dippy

Moderator
There may be people who simply think it's a toy gone walkies surely?
Does it have any messages on it that non-tea-leafs can read so than can put the boat back in the water?
 

Robin Lovelock

Senior Member
Merry Christmas Everybody ! I'm at this PC to delay my having to peel the sprouts !
In past few days I've been tweaking my page, but no change in the news or plans.
Main reason for this email is to make sure you have the link to our family newsletter
with links intended to wind-up other family members - like the elves dancing :)
Have a Great Christmas
Robin
www.gpss.co.uk/autop.htm - robot boat stuff
www.gpss.co.uk/xmas12.htm - family newsletter - enjoy ! :)
 

John West

Senior Member
Merry Christmas, Robin.

I doubt anyone would have grabbed Snoopy, as anyone who knew about the boat would have known full well about the GPS and about how many interested folks were monitoring his path in near real-time.

My guess for what happened is an electrical or mechanical failure of some sort in the salt water. Perhaps coincidence, but perhaps not.

What I would suggest for the next launch is that a manned ocean-going boat be available to follow Snoopy for a few hours, at least until he reached open ocean, clear of any near-shore winds or currents that might send him back in, and with a higher probability that the control systems were in good working order. With the sort of publicity you received with the first launch, and the search for Snoopy, I'm sure a suitable craft would be volunteered for any subsequent launch.

I assume that as long as he is hand-launched from shore and no one comes close to him in the observer boat, Snoopy would still meet all the qualifications for a legal launch. But if he failed to make it out to open ocean, then a retrieval would be almost certain.
 

Robin Lovelock

Senior Member
Happy New Year Folks ! :) Since my last post, you will see that www.gpss.co.uk/autop.htm has been tidied up a bit and new evidence added related to those hours when Snoopy went off course and hit the Needles. Checkout that Royal Marines LCU on the horizon ! :) Thanks for those suggestions - but there are much better ways of covering the "security" of Snoopy - and "openess" is probably the most effective. It's a pity my mind, at the time, was so closed to the idea of it NOT being the tide - or as I say on my page above - we could have arranged a suitable "reception committee" - with photographers! :) Meanwhile, I'm gathering bits for the next boat for Snoopy, for launch this year. Main change will probably be "procedural", in covering this aspect - particularly when dealing with my old friends who have "a little more bottle" than the rest of us ;-)
Robin
www.gpss.co.uk

p.s. "divided by a common language" ? :) "bottle" = Limey-speak for "guts"/"courage" etc.
as in "we should never have worn red and marched in a straight line" :)
 
Last edited:

PADJ

Member
Meanwhile, I'm gathering bits for the next boat for Snoopy, for launch this year. Main change will probably be "procedural", in covering this aspect - particularly when dealing with my old friends who have "a little more bottle" than the rest of us ;-)
:confused: No idea what that means - Something about a hangover?
 

John West

Senior Member
Thanks for the update, Robin, especially the meaning of "bottle." I too was wondering about that.

As a Forum member from the USA in a generally Brit forum, I work at avoiding regional (or national) slang as much as possible in my posts, but sometimes I don't even realize it IS slang. But suffice it to say, that I see British usages becoming ever more common in the US media. Phrases such as "in hospital," instead of "in the hospital," "gone missing, instead of "got lost." And, of course, I slowly pick up the meanings of the Brit phrases as they are used in the Forum itself.

As far as improved procedures for the launching of the new Snoopy, perhaps a launch from a long pier may be in order, although boat and ship traffic may be a concern in such an environment.
 

PADJ

Member
As far as improved procedures for the launching of the new Snoopy, perhaps a launch from a long pier may be in order, although boat and ship traffic may be a concern in such an environment.
At least pick a day when you don't launch downwind straight at the rocks. That's like "wearing red and marching in a straight line"
 

Robin Lovelock

Senior Member
Hi Folks. I'm making good progress on Snoopy's next boat, and - subject to weather - he may get launched on April 1st - very appropriately ! :)

Reason for this posting is that, while I wait for SPOT support, related to getting the tracker working, I've been playing with text-to-speech.

Is there a picaxe chip/board that is completely software-compatible with my servo-controller board, but with more than 2B of program memory ? I assume there isn't - but if there were - it might open up an alternative approach to the one I'm playing with.

The front page on www.gpss.co.uk/autop.htm is similar, but perhaps a little clearer on why Snoopy made that "diversion" onto the steps of that old military bunker. I have some conversations in progress, and it's remotely possible that more information becomes available on this - to amuse us all :) Meanwhile, you can see progress on the next boat on the "design" page www.gpss.co.uk/rbdesign.htm

Today, I was looking at a neater solution for the additional hardware I add for Bray Lake tests. e.g. the little loudspeaker and FM Transmitter to send information to the shore, like distance to waypoint, when at the waypoint, etc. One of the videos on my front page illustrates three methods, the last being text-to-speech (not yet on the water).

I'm thinking of a small, detatchable box at the back, taking GPS data and power from the main "lunchbox" but holding the extra hardware. e.g. FM Transmitter, loudspeaker,
maybe text-to-speech module, and at least one picaxe to drive it. If memory were not so tight, I could simply add the few SEROUT lines needed to drive the TTS, to a copy of the very same program to be used for the attempt - practically identical to that used in the 2012 attempt. It's still an option to stick to that version 1 of my autopilot, but, looking at how busy the shipping lanes are, I thought it wise to change the location of the first two waypoints - VERY CAREFULLY, of course.

Sadly, even "talking" simple things like the number (or name) of the current destination waypoint, the direction to it in degrees, whether turning left or right, whilst trivial to program, soon push the total program over the 2KB limit. Plan B would be to strip this other "talking picaxe" down to the minimum, to act as a "talking monitor". However, if I could simply add a few TTS lines to a copy of the actual program going to sea (and 24/7 tested on Bray Lake) it opens other avanues of testing, including with my GPS simulator. At present, I just see if the rudder is being moved left or right, to steer from the deliberately wobbly path, onto the next waypoint - but it would be useful to hear other information, such as what waypoint is currently selected.

Before someone says "why not use this 'speaking autopilot for the actual autopilot ?" - possible but extremly unlikely - unless maybe a 3 KB+ version of my picaxe available. The nitty-gritty of the design, including the autopilot software and GPS simulator, is on that "design" page above.

Robin
www.gpss.co.uk
 

hippy

Technical Support
Staff member
Adding PICAXE text to speech as a separate assembly is the best solution in my opinion. You only then need to define a protocol of what the master sends to it and can handle how that converts it to speech entirely independently. That makes it easier to develop, debug and integrate.

You aren't tied to 2KB if willing to go to a larger PICAXE chip. The 28X1 has 4 slots of 4KB on-chip and with I2C Eeprom you can add 32 slots, and used as data memory you can go up to an incredible amount. More than you will likely need.

A Text-to-Allophone SPO256-style / SpeakJet system should work. Maybe two PICAXE's; one taking the boat info converting it to 'word token' sequence' and a second splitting those to allophone sequences.

I feel sample-based systems sound much better than allophones and that's an alternative; especially as it can be hard enough understanding voice over radio at the best of times. The Tenda MP3 modules can have ( I recall ) 199 word / phrase / sound samples per directory and that should be enough for what you need. There are possibly other more capable modules.
 

lbenson

Senior Member
I don't remember which picaxe chip you are using, but if it's a 14M2, then you could put a 20X2 in the same socket to give 4K of programming space--the last six pins can dangle, or be snipped off, or the end of the chip can even be sawn off (this has been done with other picaxe chips, and would probably work). If you're using i2c or hser, the pinouts would be different, as, of course, are the names of the pins.
 

Robin Lovelock

Senior Member
Thanks Hippy and Ibenson. Details of the picaxe used are on that "design" link I gave earlier (also at bottom here).

That sounds promising - so what exactly is my shopping list, to end up with a chip (and board if needed, and maybe those servo lead mount pins) so that I have a picaxe board which is software compatible with what I am using and at least 1kB extra program memory ? Please keep it simple - if it's possible.

i.e. I buy the bits, follow instructions to solder together, plug in my same program load lead jack, and use the same program Editor to load my same picaxe program - possibly selecting a different chip than the faster 8 bit M2 chip currently used.

Can you confirm this is possible ? If so, can the required instructions be provided on this forum, if not already in print ?

Meanwhiloe, I'll be doing exactly as you suggest Hippy - which is my Plan A. But, as explained earlier, one picaxe has it's advantages. I had one working back in September, based on the same Autopilot software, but with most of the UK-USA waypoints removed. This was flown in my friends radio controlled model aircraft - but that's another story ! :)

Robin
www.gpss.co.uk/rbdesign.htm - that "design" page.
 

Buzby

Senior Member
Once again I concur with hippy !.

The Text-to-Allophone SPO256-style sounds awful, much better with a stored sample system.

You can hear Text-to-Allophone SPO256-style on your PC by using this app I download from somewhere : View attachment ChipTalk.zip

Good Luck with Snoopy II,

Buzby
 

lbenson

Senior Member
If there is room, a 20X2 can be plugged into an 08M2 board and programmed, giving you 4K of programming space. Whether your existing program will run (after you have appropriately renamed the pins in the program) will depend on whether you are using features of the 08M2 which don't exist on the same pins on the 20X2. Whether it would be suitable, in your environment, to have the extra 12 pins just dangling or even cut off is another question. You might be able to cut the chip off after leg 7, but surely not after leg 4--that would probably amputate the active silicon.

You could try, but a 20x2 board might be a better bet--if it would fit.
 

hippy

Technical Support
Staff member
so what exactly is my shopping list, to end up with a chip (and board if needed, and maybe those servo lead mount pins) so that I have a picaxe board which is software compatible with what I am using and at least 1kB extra program memory ? Please keep it simple - if it's possible.

www.gpss.co.uk/rbdesign.htm - that "design" page.
Too much to read and wade through for me I'm afraid !

Not sure what "software compatible" would be; any PICAXE can take data from another PICAXE. I'd say 20X2 would be the chip I'd choose, but it perhaps depends on exactly what it needs to do which isn't clear to me.

The best way to approach this is as if you were handing it to someone else and getting a finished product back, so you need to define what it will receive as input and what it does with that data.
 

Robin Lovelock

Senior Member
Good memory SRNet. Yes - the 08M2 - as on www.gpss.co.uk/rbdesign.htm under:

what bits have we used and where did we get them ? ...
etc
www.picaxe.co.uk for PICAXE computer - the AXE024 servo driver kit and faster PICAXE-08M2 chip.
etc

Sorry there is a lot of non-picaxe stuff related to this little project.
Guess you will see why I can't spend too much time on the picaxe software now.
But I'm happy to pop the software I have into other hardware - IF it exists :)

Robin

08M2 if I recall correctly ?
 

Hemi345

Senior Member
That sounds promising - so what exactly is my shopping list, to end up with a chip (and board if needed, and maybe those servo lead mount pins) so that I have a picaxe board which is software compatible with what I am using and at least 1kB extra program memory ? Please keep it simple - if it's possible.

i.e. I buy the bits, follow instructions to solder together, plug in my same program load lead jack, and use the same program Editor to load my same picaxe program - possibly selecting a different chip than the faster 8 bit M2 chip currently used.
You mention you can solder, so why not design a custom PCB? Solder a 20x2 and all the other required bits onto it rather than piece it together with off the shelf components? It seems that your base design hasn't changed for a couple boat revs, so a custom PCB would be at the top of my list... especially since most PCB shops will send you x copies of your design (http://www.oshpark.com , http://www.seeedstudio.com , etc) that you can use to build the next Snoopy.
 

JimPerry

Senior Member
Off-the-shelf is solid - Robin tests stuff for 3+ months in a wet lake. It has been suggested to use a custom PCB - but the details are not really set in stone yet ... :confused:
 

JimPerry

Senior Member
So far the Picaxe board does everything it is asked to - new ideas for Snoopy are beyond the standard board (my opinon). :confused:
 

inglewoodpete

Senior Member
The 20X2 comes in an SMD version. Before the 14M2 became available, I became frustrated with the limitations of the 14M. Realising that the 20X2 SMD is about the same size as the 14M, I designed a little adapter board so that a 20X2 could be plugged into a 14M's DIL socket. The mini project is documented here.

It offers most of the capabilities of the 20X2 in a 14-pin footprint. I have several spare adapter boards (Each a tiny 22 x 15.5mm) if you'd like to send me a PM with your details.
 

Robin Lovelock

Senior Member
Thanks Folks. I guess the short answer to my question is "no" :)

But, some good news: I JUST managed to squeeze in some useful text-to-speech (TTS) into my autopilot program, which already has the total UK-USA route, along with test waypoints such as those used for testing on Bray Lake, outside my home, etc.

The SEROUT statements make the Autopilot talk including the "I am Snoopy" on startup, speaking the direction to the selected target waypoint. e.g. "270 degrees" if due west; speaking which way the rudder is turned, steering onto this heading. e.g. "to left" or "to right"; and the distance to the waypoint, when less than 200 metres. e.g. "30 metres." These extra statements seem to work, with my walking outside my house, and only cost about 133 bytes.

So, after a bit more testing, I'll probably make the TTS, loudspeaker, and FM transmitter (for transmitting the speech to shore on Bray Lake) a simple add on box at the back of the boat, which gets the serial data and 5v power down a single servo lead.

Maybe this TTS will be left in the program tested on Bray Lake then launched at sea. It should certainly make testing easier with the GPS simulator and on the water.

Robin
www.gpss.co.uk/autop.htm - main robot boat page.
www.gpss.co.uk/rbdesign.htm - progress on the new boat.
 

John West

Senior Member
Corrosion can cause an on/off switch to fail even when it's sitting in the "on" position. The corrosion can lead to a high enough contact resistance that power will fail. Perhaps a sealed latching relay may be the elegant solution, although I'm the simple minded sort who would just twist the wires together and solder them with a cordless iron just before the launch, cover the connection with 5 minute epoxy and call it good.

A major difference between months on Bray Lake and months on the high seas is obviously the salt water. Is there any chance the PV panels will get coated with enough salt that you'll lose power? I apologize if you've already addressed this in the docs, Robin. It's a very substantial project with more info published than I have the time to fully read.
 

srnet

Senior Member
Corrosion can cause an on/off switch to fail even when it's sitting in the "on" position. The corrosion can lead to a high enough contact resistance that power will fail.
Well yes.

Shirley you would not use a mechanical switch for an application like this, unless it was a completely sealed type and completely immune from water\salt ingress ?
 

John West

Senior Member
They did indeed have such a switch fail, which is why they are contemplating completely sealed (buried in the hull) normally closed reed relays and such.
 

John West

Senior Member
That looks like the sort of device that might work, but they need something that can reliably handle more current. I'm still of the "solder it on and coat it with epoxy" persuasion.
 

Hemi345

Senior Member
Yeah, heck, even those irrigation system grease caps I used to waterproof the solenoid wiring connections would be a reliable option.
 

Robin Lovelock

Senior Member
Hi Folks. Thanks for the comments about the switch - everything is important. Just to say here that I've been updating the "design" page, day by day, on www.gpss.co.uk/rbdesign.htm as the new boat has taken shape. I expect the sails to be delivered soon, and Snoopy may begin testing on Bray Lake next week. That design page shows the text-to-speech in it's box at the back (part of the FM transmitter) and there is a video (end of autopilot software section) showing the TTS during the Atlantic crossing with the GPS simulator.
 

Robin Lovelock

Senior Member
Hi Folks. I just posted this to the [Microtrasat] list, and someone here may know better how to do it.....

Many Thanks Folks - I've changed the title to "[Microtransat] low power compass"
since it has little to do with raspberry pi which consumes too much power for me.

Here is a specification for a low power compass subsystem, and maybe someone out there
could implement it, including the handful of source code lines needed to
read any I2C non-"rs232" serial data from a compass chip, and squirt out
rs232 data (e.g. "H090" at 4800) to the autopilot picaxe.
Maybe, if needed, smoothing logic. Kalman filter based if they really must :)

Kalman filters ? Ahh - those were the days, in 1970, when implementing
the military radar tracking software to go on board UK Royal Navy Type 21 Frigates.
Our prototype used a kalman filter, but we ended up with simple alpha-beta smoothing.
KISS. Sorry I digress :)

I'll paste this Microtransat posting onto my picaxe forum thread, since that is probably
where I'm more likely to find someone who actually does it - including
what might be weeks or months of building and testing, rather than
a few minutes talking about it, like I am doing here.

The relevant links are on my www.gpss.co.uk/rbdesign.htm page.

If someone succeeds, and shares the "shopping list" (< 100 USD total ?)
and picaxe program ( < 20 lines of code ?) then maybe I can use it
in my boat for 2014. It seems unlikely it would be before then.

Here's an outline spec for the compass subsystem:

Preferred compass chip: whatever you like that's suitable. Ideally it does't need a processor.
Preferred processor if needeed: a picaxe - familiar to me, including program loading tools.

Power consumption: < 3mA from 5v
(including chip, picaxe, and any power conditioning if not able to run off 5v)

Output: rs232 text (0v-5v swing) at 4800: magnetic direction in degrees clockwise. e.g. H090 <CR>
Rate: output at 1 Hz (but you may choose to take data faster from chip and smooth it)
Accuracy: better than 5 degrees; target accuracy 1 degree.
Time constant for smoothed output: less than 3 seconds to reach a stable direction.

Any student wanting to take this up, could obviously start with a first issue of software
that would immediately be useful. If they wanted to make it a more ambitious project,
they could easily extend it to provide "true heading" instead of "compass heading"
although that might be difficult without a low power GPS to provide date and location.
Probably better to KISS :)

Meanwhile, today I expect to receive the sails from Mr Postman,
for Snoopy's new boat that should be starting tests on Bray Lake next week,
prior to his next attempt from Barton-on-Sea - maybe on 1st April ! :)

Robin
www.gpss.co.uk/autop.htm
 
Top