Joined: 20 Jul 2007
Posts: 2
Location: Victoria, Australia
Custom Radio Control System
Hi,
I'm a year 11 student and I've started creating a bot with my mate.
I was wondering, (as it was not to clear in the rules) are pic's and wireless modules allowed (not sure if thats the proper name, http://jaycar.com.au/productView.asp?ID=ZW3100).
I have had some experience with using this combination, and would love the experience of using this system in the bot.
Thanks.
Fri Jul 20, 2007 9:10 pm
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
a few people use the 900mhz modems like zigbees and the like i believe, but those things are the kind they use on remote garage door openers and such. im not sure it would have the ability to drive a proportionally controlled robot.
would probably be able to do on / off control. and the range isnt too flash on them.
Joined: 30 Sep 2006
Posts: 673
Location: Perth, Western Australia
I don't think there's anything in the rules preventing you from using those 433MHz modules, but I have heard that they pick up tremendous amounts of static.
Pics, go nuts! Jake uses them in his custom 900MHz control system, and some of us are running around with picaxe speed controllers. Just make sure that they failsafe
Fri Jul 20, 2007 9:22 pm
TheGubble
Joined: 20 Jul 2007
Posts: 2
Location: Victoria, Australia
Thanks for the quick response!
I'm down in Victoria and I'm just looking through the events section of the forum to see whats on down at SideTracked.
I'm glad that i can use pic's and the wireless modules (I'll have to have a look into the interference, as i have only used those modules close range on 2 breadboards).
Thanks all.
You probably already noticed this thread but just in case I thought I would mention it. I have one of Bretts versions and can bring it to our next builders meeting if you want to come over and check it out. _________________ Satisfaction is proportional to effort and results.
Fri Jul 20, 2007 9:42 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
i use maxstream 900mhz modules. They are pretty nifty basically. about 100m range or so, (or good signal through the length of a house). ~$60 each though. But they "just work"
Dumhead (andrew) tried using those with picaxe in stealth but he had lots of problems getting serial data to work. (i think he was doing serial not PWM)
@Glen They are 433mhz radio modules you can in theory send serial data over them, I've never used them.
I wouldn't use picaxe's they are the same price/more expensive than a pic and do much less. Take a look at a PIC 16F877A thats what we use to replace the brain of the IBC. 2 hardware PWM outputs, hardware serial port, interrupt on change pins,2x hardware timers/clocks. All the stuff you need to make a robot controller work at 100%, none of this try and read a pulse in and don't do anything else while you wait stuff.
To program it use JAL version 2 is out and its got arrays and all the other fun stuff you could want. (and its free). To program the chip I recommend the pickit 2 direct from microchip for ~$50 or so. It'll program just about any microchip type chip out there.
Alternatly you can look at the AVR line of micro controllers they have a boatload of open source(free) stuff supporting them and they are fast. _________________ Mechanical engineers build weapons, civil engineers build targets
Sat Jul 21, 2007 10:51 am
DumHed Experienced Roboteer
Joined: 29 Jun 2004
Posts: 1219
Location: Sydney
I couldn't get serial to work reliably with the 433MHz modules so I changed to a PWM system, which worked perfectly at home, and not at all in the arena _________________ The Engine Whisperer
- fixer of things
Mon Jul 23, 2007 1:17 pm
NMO Experienced Roboteer
Joined: 16 Jun 2004
Posts: 486
Location: Melbourne
Hey TheGubble,
We're having a builders meet at my place on the 25th August which you are most welcome to come along to, You could have a look at some of the systems that we use then (Although most of what shows up will be hobby radio based). We have a bit of a chat about robots etc and I'm throwing on a sausage sizzle etc.
I've heard good things about the zigbee modules although never used them myself. The thing to be aware of is that a LOT of aussie builders are now using the spektrum radio systems which operate on 2.4Ghz and fairly efficiently take out most other systems on the band (they completely kill wireless cameras etc).
I did try playing with the 433 modules from jaycar for a while however I could never get reliable comms through it.
Ah im trying to communicate between between two 433mhz modules from oatley but I can get the PICs to run at all. ATM im just trying to get some lights to flash. I am using the 16F628A I thought that all you needed was vdd and vss connected to get it to run with int oscilator. I since have pulled MCLR high but I didn't think this was necessary. Im sure its the same thing I do everytime I build a board. Anyone tell me what im missing so I can test these boards. _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Thu Jul 26, 2007 10:03 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
unless you disable mclr in the fuse bits then you will need the mclr resistor.
make sure your fuse bits are also set to use the int-osc.
If you are trying to serial data than int-rc isnt going to be accurate enough (especially when one is inside a bot next to 100C motors) you are at least going to want a ceramic resonator and preferable a crystal. _________________ Mechanical engineers build weapons, civil engineers build targets
Thu Jul 26, 2007 10:22 pm
Fish_in_a_Barrel
Joined: 30 Sep 2006
Posts: 673
Location: Perth, Western Australia
Any thoughts on where I'd be able to find information on building a trainer box, to control my spektrum from some pots? _________________ They say that he crossed the fine line, from insanity to genius.
Fri May 30, 2008 12:47 pm
Fish_in_a_Barrel
Joined: 30 Sep 2006
Posts: 673
Location: Perth, Western Australia
So I was bored tonight and put a CRO on a trainer cable attached to my transmitter.
The signal looked nice enough to replicate, for all sticks in the middle they each had an on time of about 1.1 ms, with a spacer of 0.4ms. Then there was a low synch period of about 11ms. Also from full on to full off is a range of 0.8ms. Voltage was 1.4V _________________ They say that he crossed the fine line, from insanity to genius.
Wed Jun 11, 2008 12:15 am
Spockie-Tech Site Admin
Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia
This is probably a good place to start
http://www.rcgroups.com/diy-electronics-199/ _________________ Great minds discuss ideas. Average minds discuss events. Small minds discuss people
Wed Jun 11, 2008 1:03 am
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