Just realised Plan-G didnt have a thread.
Plan-G will be attending the next event (we hope)
however it wont be the same Plan-G

or is it Plan-F will be attending

i'm not sure.

its sort of the illigetimate child of a shotgun marrage between Plans F and G with a banjo playing in the backround. Plan-A is the Grand-pappy or something, perhaps a cousin called igor.

spent all day getting my PIC programming environment back up and running and finding the code for the radio. We need to add a wep control to the 900mhz system to run the victor. Damn I hate servo pulses its going to hose the radio something nasty.
_________________
Mechanical engineers build weapons, civil engineers build targets

mmm battery goodness
shame about the picture


_________________
Mechanical engineers build weapons, civil engineers build targets

Looking very nice!
Still, be careful with shorts... one of my packs cells shorted with itself after a singularity impact so I wouldn't like to see an impact send those cells shorting with the aluminium!
So is it a drum like plan F was?
_________________
( •_•)

( •_•)>⌐■-■

(⌐■_■)

YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

you can see in the pic at the bottom the urithane insulation in there same as the last time.
basically we cast the urithane inside an aluminium cap top and bottom so we shouldnt have those flexing problems we had last time.

Got the radio running with a servo output.
it has however hosed the good signal rate. :-<
still it seems "ok" at the moment.
need better error checking than what i have at the moment but apart from that.
_________________
Mechanical engineers build weapons, civil engineers build targets

w00t
Its ALIVE
quote of the moment
"hmmm i really need to do some work on that failsafe code"

well i managed to get the radio working using timer interrupts rather than fixed delays and it has made a masive difference to the recieved signal. before the "signal error" light was on almost constantly now its back to the occasional flicker.

In operation, its twitchy as heck. I'm going to cut drive motor power to 50% and then limit the steering to 50% as well which might help.
I want to get one of these
http://www.sparkfun.com/commerce/product_info.php?products_id=741
and stick that in and use it for traction control.
with our current radio it would mean i would have to do the quackulations on the bot itself but if we can get bluetooth happening then the data rate and latency should be low enough that it can be farmed off to the controler for 32 bit calculation lurvin.

my current checksum system dosent seem like its quite up to snuff.
(or theres some logic bug)
basically the scheme is like this

code:

---

        if (packetmode == 1) then
           -- we are recieving a motor drive packet
           if rxptr == 2 then seqid = rxdata end if
           if rxptr == 3 then ch1 = rxdata end if
           if rxptr == 4 then ch2 = rxdata end if
           if rxptr == 5 then ch3 = rxdata end if
           if rxptr == 6 then opts = rxdata end if
           if rxptr == 7 then
              -- packet finished
              check = rxdata
              -- check validitity
              var byte doublecheck
              doublecheck = 0
              doublecheck = doublecheck + packetmode
              doublecheck = doublecheck + seqid
              doublecheck = doublecheck + ch1
              doublecheck = doublecheck + ch2
              doublecheck = doublecheck + ch3
              doublecheck = doublecheck + opts

              if (doublecheck == check) then

---

That's some nice work Jake

Someday I'd like to have a crack at such an interesting project such as your PC 900mhz radio. Keep us posted

PS: Pics or BAN!
_________________
https://www.halfdonethings.com/

Jake, you could also try deviding all the values by 5 or 10 before you ad them togeather to stop them going over 256.

problem with dividing by 10 is i am only doing integer maths, so 3/2 = 1 (or 2)
and for small values it would loose alot of information.
the general way of doing it is to add up all the values into a 16bit variable then divide that by some number and your checksum is the quotient and remainder of that,
But thats too much like hard work.
Perhaps in JAL V2 i'll do that, it has 16 and 32 bit variables built in.
_________________
Mechanical engineers build weapons, civil engineers build targets

Event report
Status : crappy.
Physically the bot is fine. In our first fight Vs road kill we went the full 3 minutes and the battery pack was a bit warm, dad could keep his hand on it, i couldnt, we are calling that 65c ;->
During the fight though the bot was very jerky, driving in spurts but i didnt notice the failsafe or bad signal lights flashing. If anybody has vids i'd like to see them. Weapon was a little underwhelming, I think the diamiter is just too low to really get the KE we were looking for. Orbit seems about 2-3x more effective. We never really got a good hit in on roadkill though so who knows.

Second match Vs cobra, everything was going fine, wasnt too jerky, Then we got a big hit on cobra (about 20 seconds in) and it went to crap, i lost all drive )pretty much though the wep was fine. Turns out one side died and we only had forwards on the other. We had one more big hit and we were dead. When i got into the arena and killed the power the "everything's OK" light wasnt on, niether was the failsafe or the bad signal light, perhaps most worrying the "sometimes turns green" light was also not on. Anyway put it on the pit table and turned the power on and all was well. Killed my assumption that we had just popped a controller chip off the board :-<

We ruled out continiuity problems in the brain transplant cable and i got the multi meter onto the PWM pins and we could see the voltage change as i changed throttle so the PIC and everything seemed to be working so then we tried swapping the hip chips over. Turned the thing on and nothing much happened "ok" light was good, i tried driving it a bit then there was a big spark type bang that i didn't see but heard, dad said it was coming from around the area between the HIP's and the fets. Either way then we had no motor drive.
The fets seem un-explodificated but with the amount of carbon on the board i'm amased something hasnt happened before.
I cant think what could take out 1.5 H-bridges in one hit, the only thing i can think of is the metal blocks that the FET's heatsink to touched? not quite sure what that would do right now, my brain isnt working, but its the only plausiblle explination i can come up with.

Next Plan is to go sensored brushless.
_________________
Mechanical engineers build weapons, civil engineers build targets

plan g was very cooool

i honestly think u rebuild rhe body though as there was ALOT of unused space inside the robot and the body was very big for what was in it, making it alot more compact would mean better driving (hopefully and more weight saved and such
_________________
Andrew Welch, Team Unconventional Robotics

Got a replacement V1.3 IBC off Jeff-f Via Glen on thursday. Way better in terms of design I must say, good ground planes etc. During the battles it hardly even got warm though i must admit i was handling it with kid gloves, partly because it was somebody elses IBC partly because the bot tended to do 180's if it got too sideways. (24V running drill cells limited to 50% drive, though in the jolt match i did add a scroll bar to vary the "nerf" level ;-> ie adjust the drive power limit)

Fight 1 was jolt, the most feared.
We went far better than I expected to lol. Had our "good" battery pack in (as opposed to the one with all the dodgy cells in it). We put the "jolt catcher" steel on the front and the undercutting blade thingie on the back which caused us to be sitting up off the ground before some minor adjustements were made. We had to go with the polycarb lid for this one because of the weight.
Basically because the bot just kept flinging sideways i just kept the throttle real low and aimed the nose at jolt then advanced slowly lol. Somehow we managed to "wedge" jolt a few times which let me open it up a bit as jolt acted as a pretty good stabiliser. Jolt caught the catcher a bunch of times making lots of pretty sparks ;-> bent it a little in a few places but all in all it just worked w00t. Jolt caught the glass a few times (only just) but that stood up well, looked like it got a bit of a hair cut was all. The poly carb "flexed" untill it shattered sending a chunk flying outta the way. Highlight was wearing jolt like a hat with the bar going madly on top ;->

Fight 2 was against cobra.
We put the drum on and were hoping to see the hard facing on the teeth actually stand up. It did w00t. Turns out the trick is to weld an inch then quench it. All was going according to plan (yes us getting picked up and thrown around the arena is part of the plan as was driving straight up the wedge and using it against your spikes ;->) with us gouging bits of glens spikes off and bending assorted peices. Untill glen must have nicked a belt which made it slip off to one side by 2 V's where it rubbed on the side of the bot, making mucho smoke. Glen however was also having intermittant drive at that point so we decided to call it a draw. (our bot was fine, could have continued running but i guess i'm just paranoid wrt smoke pouring outta the bot)

Fight 3 was roadkill.
Off to a bad start with the bot stopping all the time, I updated the controller firmware recently to include a 1 second delay on startup to help aleviate the "tick" it had when it turned on, this combined with i think a really bad cell in the pack lead to the bot basically halting whenever current was drawn or whenever a connection bounced. We pulled it apart and did the battery pack up which seemed to fix the problem somewhat but it still intermittantly froze during the match. Was fairly energetic match with lots of turning competitions, angus driving in a ring around us with me trying to turn fast enough to get the weapon on him without spinning out. All in all I think it was anguss' driving and reliability that won him the match. No complaints wrt that judgement here.
_________________
Mechanical engineers build weapons, civil engineers build targets

Well blew up Jeff's IBC at the last event the logic power supply died, i did the old 9v battery trick but that was as fragile as always.
Found a supplier who would sell me the chips for $12 rather than the $36 RS and farnell wanted, (linear's Australian distributor sonar (or something close) they also have 1405's pretty cheap, credit card orders online and next day shipping for $

Only problem is they didn't have the high voltage version of the chips so its back to "receiver" batteries now but thats not a bad thing. separating the fragile logic supply from the 50V spikes that come in on main battery cant be all bad. If i can get one of those teensy 3 cell LiPo packs that should last all day and with the lt1170 in place it wont matter if they get flat (and they should handle ~150ma current draw a tad better than a 9v battery ;->)

Hopefully that will fix all the problems Plan-g has been having (crosses fingers)
_________________
Mechanical engineers build weapons, civil engineers build targets

Jake, i've got sonar's catalogue. Want it?
_________________
( •_•)

( •_•)>⌐■-■

(⌐■_■)

YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

I'll take a squiz at the next event perhaps?
their website is pretty good though so no rush.
_________________
Mechanical engineers build weapons, civil engineers build targets