Putting robotics at your service™

Free shipping on orders over $200

DIY custom 2.4ghz RC radio system for robotics...

Print view Share :
Previous topicNext topic

Page 10 of 20 [ 289 posts ]

1 ... 7, 8, 9, 10, 11, 12, 13 ... 20
User avatar
Guru ( offline )
Posts: 9256
Posted: 2008-12-10 13:48 
I have been carrying a big box of parts back ad forth from work and home. Not making much progress due to little free time. I asked James to help me get them finished. It's been too cold to get the sand blasting done but remain hopeful. Just so you know progress is being made.


_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


User avatar
Guru ( offline )
Posts: 3578
Posted: 2008-12-10 14:00 
Man that raidio looks like a serious piece of hardare. I love the flat black look!

Are you going to hand build them all? or offer them as kits? If they are offered as kits you don't have to hand build each one. I'm not even sure if you're planing to add them to your line of radios or not. :lol:

_________________
Mike

The robotics nut.


User avatar
Guru ( offline )
Posts: 9256
Posted: 2008-12-10 14:44 
Hi Mike,

The radio is very much a prototype. I have 3 separate "entities" that are very interested in making it a real product. Because it's a transmitter I'm limited by the FCC in what I can do. It will probably never be a kit though. No way to tell what will come of it, but I'm more interested in making the concept available to the general public to advance the hobby robotics industry as I am in making it a product. Legally anyone can do this on their own as a hobby project, I.e. not selling them...

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


User avatar
Guru ( offline )
Posts: 2120
Posted: 2008-12-10 15:29 
:shock:
...

:twisted:
...

:shock:
...

8)


Looking good Jim!

_________________
Kåre Halvorsen, Zenta
-----------------------------------------
Zenta's blog
http://zentasrobots.com/
Zenta's YouTube channel
http://www.youtube.com/ZentaOlbaid
-----------------------------------------


Guru ( offline )
Posts: 2158
Posted: 2008-12-10 15:39 
heh, the word "wow" first came to mind, followed very shortly by "cool..."
8)


User avatar
Expert ( offline )
Posts: 536
Posted: 2008-12-10 15:43 
EddieB wrote:
heh, the word "wow" first came to mind, followed very shortly by "cool..."
8)

The word "wow also came to my mind.. but it was followed by "Oh wait.. I made those..." 8)

_________________
Curiously enough, the only thing that went through the mind
of the bowl of petunias as it fell was "Oh no, not again."

James "Don't call me Jim" Frye
Lynxmotion, Inc
http://www.lynxmotion.com


Guru ( offline )
Posts: 2158
Posted: 2008-12-10 15:54 
Fish (Admin) wrote:
EddieB wrote:
heh, the word "wow" first came to mind, followed very shortly by "cool..."
8)

The word "wow also came to my mind.. but it was followed by "Oh wait.. I made those..." 8)

:lol: I live that from time to time. ;)


User avatar
Guru ( offline )
Posts: 3578
Posted: 2008-12-10 16:08 
Robot Dude wrote:
Hi Mike,

The radio is very much a prototype. I have 3 separate "entities" that are very interested in making it a real product. Because it's a transmitter I'm limited by the FCC in what I can do. It will probably never be a kit though. No way to tell what will come of it, but I'm more interested in making the concept available to the general public to advance the hobby robotics industry as I am in making it a product. Legally anyone can do this on their own as a hobby project, I.e. not selling them...


You could just sell the chassis and leave the radio stuff out... Muhahahahahaaa! :twisted:

J/K, I understand... It looks fantastic... very impressive.

_________________
Mike

The robotics nut.


User avatar
Guru ( offline )
Posts: 9256
Posted: 2008-12-11 14:28 
Time for some technical content. I have started the receiver side program. This is where we read the AUX2 or Channel 7 pulse length to know which pin is being pressed. I wrote a simple program to display the value in a terminal window.

Code:
pulse_value var word
input p3

start:
pulsin p3, 0, pulse_value
serout s_out, i9600, [dec pulse_value, 13]
goto start


Here is a list of the key, the value in the program, the measured value.

Code:
  prog measured
N 1100 1144uS
0 1150 1193uS
1 1200 1243uS
2 1250 1292uS
3 1300 1340uS
4 1350 1390uS
5 1400 1439uS
6 1450 1490uS
7 1500 1538uS
8 1550 1589uS
9 1600 1637uS
A 1650 1687uS
B 1700 1736uS
C 1750 1786uS
D 1800 1835uS
E 1850 1885uS
F 1900 1934uS


This is fine for doing some if-then statements to turn things on and off. Not sure why the discrepancy in values though. If the program is supposed to generate a 1100uS pulse, why is there a 40uS-ish discrepancy? I'm not doing any interupt or debug or even any terminal commands in the transmitter code. I measured with both a scope, and an Atom Pro doing a pulsin and serout-ing to a terminal with the same results.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


User avatar
Guru ( offline )
Posts: 9256
Posted: 2008-12-11 15:18 
Moving on...

Here is a little program to turn on and off the A, B, C led's on the receivers Bot Board II. They follow the keypresses exactly.

Code:
pulse_value var word
keypress var byte
input p3

start:
pulsin p3, 0, pulse_value
;serout s_out, i9600, [dec pulse_value, 13]
if pulse_value > 1662 and pulse_value < 1712 then
  keypress = "A"
elseif pulse_value > 1712 and pulse_value < 1761
  keypress = "B"
elseif pulse_value > 1761 and pulse_value < 1811
  keypress = "C"
else
  keypress = " "
endif

if keypress = "A" then
  low 12
else
  input p12
endif

if keypress = "B" then
  low 13
else
  input p13
endif

if keypress = "C" then
  low 14
else
  input p14
endif

goto start


I'm using these values for the pulsin if-then statements.

Code:
N 1119 - 1169
0 1169 - 1218
1 1218 - 1268
2 1268 - 1317
3 1317 - 1365
4 1365 - 1415
5 1415 - 1464
6 1464 - 1515
7 1515 - 1563
8 1563 - 1614
9 1614 - 1662
A 1662 - 1712
B 1712 - 1761
C 1761 - 1811
D 1811 - 1860
E 1860 - 1910
F 1910 - 1959

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


User avatar
Guru ( offline )
Posts: 2120
Posted: 2008-12-11 15:40 
Hi,

It seems like the 40µS-ish (µS not uS .... :wink: ) tends to get shorter when the main puls gets longer? :?

But as long as the values of the main pulse from the receiver are stable and don't varies to much (about +/- 2µS ?) it should be ok.

_________________
Kåre Halvorsen, Zenta
-----------------------------------------
Zenta's blog
http://zentasrobots.com/
Zenta's YouTube channel
http://www.youtube.com/ZentaOlbaid
-----------------------------------------


User avatar
Guru ( offline )
Posts: 9256
Posted: 2008-12-11 16:18 
zenta wrote:
Hi,

It seems like the 40µS-ish (µS not uS .... :wink: ) tends to get shorter when the main puls gets longer? :?

But as long as the values of the main pulse from the receiver are stable and don't varies to much (about +/- 2µS ?) it should be ok.


Just more curious than anything...

Don't make me do Alt+0181 just for that... :P

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


Novice ( offline )
Posts: 54
Posted: 2008-12-11 18:35 
Jim

Since your using a reciever and transmitter that is already FCC approved I dont see why you cant sell this as product. If you wanted to. You in no way modified the radio system therfore its still approved.

paul


User avatar
Guru ( offline )
Posts: 9256
Posted: 2008-12-11 18:43 
PK wrote:
Jim

Since your using a reciever and transmitter that is already FCC approved I dont see why you cant sell this as product. If you wanted to. You in no way modified the radio system therfore its still approved.

paul


Yeah I know, but it's a grey area at best. I think I'll pass. ;)

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


User avatar
Guru ( offline )
Posts: 9256
Posted: 2008-12-11 18:54 
Robot Dude wrote:
Not sure why the discrepancy in values though. If the program is supposed to generate a 1100uS pulse, why is there a 40uS-ish discrepancy?


I did some testing and worked with Nathan... I know what the cause is. The overhead to get into the pauseus command after exiting the pusleout command is the culprit. The more complex the arguments for the command the longer it takes to get into the command. Takes less time to load a constant argument than a variable one, and it takes less time to load a variable than to calculate an expression. 8) Here is how I implemented the build PPM function.

Code:
makepulses:
pulsout 15,800
pauseus ((cha1*2)-800)
pulsout 15,800
pauseus ((cha2*2)-800)
pulsout 15,800
pauseus ((cha3*2)-800)
pulsout 15,800
pauseus ((cha4*2)-800)
pulsout 15,800
pauseus ((cha5*2)-800)
pulsout 15,800
pauseus ((cha6*2)-800)
pulsout 15,800
pauseus ((cha7*2)-800)
pulsout 15,800


So I broke some rules there. I need to do the math and send the results to variables, then do the above routine. There will be some overhead but once it's calculated it should be constant in all the values, therefore making it possible to subtract it out. Yehaa! Mystery solved. 8)

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


1 ... 7, 8, 9, 10, 11, 12, 13 ... 20

All times are UTC - 5 hours [ DST ]. It is currently 2014-11-23 14:36
Feedback Form
Feedback Form