SRLM said...
....I need about 24 10 mOhm resistors.
SRLM,
if by mOhm you mean Mega Ohms, try this:
Take a number 2 pencil and scratch a 4 or 5 inch heavy line along a sheet of paper. Now take your multimeter and measure resistance at various points along it.
If by mOhm you mean milli-ohms, then cantcha just coil up some wire???
Yeah, I tried the lead trick, but a single .5mm gave me about 20 ohms, and a strip 11 inches long gave me about 50 kilo ohms. What I need are resistors in the mega range... Plus, how you do reliably attach a wire to a piece of paper? I'm sure you can tape it, but it wouldn't be very durable...
On a site online, I saw how to make a capacitor: two sheets of aluminum foil separated by a piece of paper, with a book on top. Seemed like a quick solution if you're in dire straights...
SRLM said...
Yeah, I tried the lead trick, but a single .5mm gave me about 20 ohms, and a strip 11 inches long gave me about 50 kilo ohms. ...
I'm surprised. I try that same thing on an index card and I consistently get 2 or 3 MegaOhms per inch. Could humidity or the type of paper be a factor? As for making connections, did you try something like alligator clips or paper clips?
Has anyone ever tried using bobby-pins to make connections? Are alligator clips disqualified?
Too bad in-tact pencil leads have little resistance. Drawing a thick line on paper does make a big resistor though.
Heres my entry Its a RC Car turned in to a robot.
I use some a coat hanger to make the the front bump sensor. I use two screws to hold the coat hanger on to the front. and solder a wire to the coat hanger. I also us some hook up wire wraped several times around the front to make it complet the circuit for the front sensors." />
I was luck that when I took the RC car apart to find that the h-bridge for the rear wheels were on a seperate pcb. On the front wheel its like a servo but its now pulse width modulated it is a simple H-bidge. The other nice thing is that both h-bridges had pull down resistor. The one thing that I did have to do was change the way the wires for the rear wheels where soldered to the pcb because it was diffrent from the front wheels.
Heres a shot of the connector for the steering. On the connector the red wire is positive the black wire is negative and the yellow and white wires are for controlling the h-bridge.
Heres a shot of the connector for the rear wheels. On this connector the yellow and white wires are the same as on the steering but I'm not useing the red and black wires becasue on the RC tbey were used to send power to the radio reciever. Bu the·proto board is pulling the power straight from the battery.
On the protoboard I used the resistor for the VGA connector to provide some current limiting for the two H-Bridges
And I used the pull ups from the mouse connector to give a bias to the bumper sensores
The things I want to do next on this project is to add some encoders to the rear wheel so that it would be possible to better control the speed. I would also like to replace the front bump sensors with some thing like the ping so that it would not have to hit the walls. The other thing I want to do is find away to make it steer better because right now it can change its direction to any large degree.
I'm going to add my code later because it on my computer at my house and I only have internet at my moms.
Code now uploaded
Post Edited (Cole Logan) : 2/20/2009 5:20:35 PM GMT
I know you have a $1 limit, but every good grandma should have a drawer of hobby servo's- right? And if not, you can get them on ebay for like $3- so close enough for government work- a trillion here, a trillion there, who's gonna miss $2?
And it's a really cool application- using computer vision to control the position of a servo!
Here's what my dad did a couple days ago:
- connect a hobby servo to the ProtoBoard, black to ground, red to +5, white to pin 9.
- mount whatever you want on the servo top- he used a pointer, but you could put a camera, a doll's head...
- control the hobby servo with the bs2 object from obex (you could also use the servo32 object)
- drive the servo with the position provided by ViewPort's OpenCV filter. Currently, ViewPort let's you capture video from a webcam, a file, or a Propeller frame grabber- he used a webcam. Then, you can select from a HSV color blob finder, a Viola Jones object finder (great for finding faces), or a Hough circle finder. All provide an x,y, width, height result to the Propeller. For this application he uses just the x position.
Here's the code:
CON
_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000
OBJ
vp : "Conduit" 'transfers data to/from PC
qs : "QuickSample" 'samples INA continuously in 1 cog to 20mhz
BS2 : "BS2_Functions" ' Create BS2 Object
VAR
long pwmst[noparse][[/noparse]100]
byte pw1,x1
pub findblob|pos,x,y,a
vp.config(string("var[img]http://forums.parallax.com/images/smilies/tongue.gif[/img]os,x,y,a"))
vp.config(string("dso:view=[noparse][[/noparse]x,y],timescale=1s"))
vp.config(string("video:source=webcam0,mode=face,result=pos")) 'use video from the webcam, filter with the face mode, and write packed result to the pos spin variable
vp.config(string("start:video"))
vp.share(@pos,@a)
BS2.start(1,2)
cognew(servopwm(@x1),@pwmst)
repeat
x:=pos & $3ff '0-1023
y:=pos >>10 & $3ff
a:=x+y
x1:=x/4 '0-255
pub servopwm(x11) ' generate PWM
repeat ' for servo
pw1:=byte[noparse][[/noparse]x11]
BS2.PULSOUT(9,1*500+3*pw1) ' 1-2.5 ms 2us/cnt
BS2.pause(25) ' 25 ms
See the picture- it shows his setup with a laptop running ViewPort, a webcam, his "Protoboard/IODreamkit", and a servo with a pointer. The bottom row show the servo pointing to different recognized objects. I'll do a video one of these days, everything is done continuously in real time, so if you move one of the objects, the servo follows! ViewPort v4.1 is now released- it comes with a 30 day free trial...
Hanno
There are resistors on the pcb for some of the vga - you can use them in ways to generate tv (maybe not the best, but I am sure you can get a display out of them)
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Links to other interesting threads:
Since you let the cat out, that was one of several tests I did two Saturdays ago when I was
preparing this little game. An easy 32 colors can be achieved easily. [noparse]:)[/noparse]
It was mentioned earlier about your TV thread, but noone seemed to take the bait !
I dont have the time with my other projects, but this is really a great idea OBC. When the contest expires I will post what I thought of - requires no special parts.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Links to other interesting threads:
Since "Fluffy" is already out of the bag, I thought I would pass this along.
Excluding the idea of using the resistors that are already available on the board for TV, I initially had thought using pencil lead would be an attractive alternative to the TV resistors.
Then I thought using capacitors (home made) that were proportionally ratio'd would work in place of the resistors all together... ehhh sort of works.
My final thought is without using any resistors or capacitors at all... Yup! For "crude" TV you can get away with using 2-pins directly off of the Propeller without any resistors or caps.
You have to play with the colors a bit, and they are not what you would expect them to be, but it does work.
I changed the graphics pin mode to %000 instead of the default %001, and connected the video input to P5, while the video ground is using any I/O pin configured as an Input. Connecting
the video ground to VSS provided too much signal and the video washed out. The small amount of parasitic capacitance on the I/O pin is just enough... did I say capacitance? Ok well I used
a parasitic capacitor from the Propeller IC.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Beau Schwabe
IC Layout Engineer
Parallax, Inc.
Wrap up those projects and post them! I'm doing my shipping Monday or Tuesday and
want to ship these two Protoboards I'm sitting on my desk. [noparse]:)[/noparse]
His Prop-controlled RC car is believable that it would be found at grandma's house, and
project certainly meets the qualifications.
Hanno's project is a close second, but his use of a servo disqualified him.
(Sorry, I just can't picture an extra servo at grandma's house, and I've never seen them sold for $.99 (Or less)
Cole, PM me your address and I'll ship two USB Protoboards to you this week!
Thank you very much, and thank you for puttung on these great contest. I promised my little brother that I would give him one of the boards but I think that I will make him have to use the one that I got him for x-mas first.Hanno your project looks really cool to.
However, I must object a little (when do I not ... lolz) to the notion that a servo would not be found in an RC car that could be found in Granny's garage. No instant replay rule I guess [noparse]:)[/noparse]
Congrats to Cole and Hanno, and to OBC for running the contest.
My thoughts were to make a dice display on the TV using a couple of wires to make a switch. Use the switch to count a random number of clocks in the CNT register and do a mod 6, then add 1 to the remainder. I didn't have the time but I did pick up on OBC's hint about the TV object
Thanks again OBC - you make the forum fun
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Links to other interesting threads:
Comments
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
PG
Think poor, don't have much, must work with what is there..
Be creative. You are must less restricted than you think. [noparse]:)[/noparse]
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
SRLM,
if by mOhm you mean Mega Ohms, try this:
Take a number 2 pencil and scratch a 4 or 5 inch heavy line along a sheet of paper. Now take your multimeter and measure resistance at various points along it.
If by mOhm you mean milli-ohms, then cantcha just coil up some wire???
If you need a capacitor, think: Ben Franklin.
On a site online, I saw how to make a capacitor: two sheets of aluminum foil separated by a piece of paper, with a book on top. Seemed like a quick solution if you're in dire straights...
Is there a restriction on the amount of hookup wire one can use?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Beau Schwabe
IC Layout Engineer
Parallax, Inc.
I'm surprised. I try that same thing on an index card and I consistently get 2 or 3 MegaOhms per inch. Could humidity or the type of paper be a factor? As for making connections, did you try something like alligator clips or paper clips?
No, I didn't restrict wire..
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
Too bad in-tact pencil leads have little resistance. Drawing a thick line on paper does make a big resistor though.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
--Steve
Nope... From the original post..
* Hookup wire. (22 gauge wire isn't in every home, but we'll give you this one, even alligator clips.)
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
--Steve
Have I stumped you guys this time??? [noparse]:)[/noparse]
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
I use some a coat hanger to make the the front bump sensor. I use two screws to hold the coat hanger on to the front. and solder a wire to the coat hanger. I also us some hook up wire wraped several times around the front to make it complet the circuit for the front sensors.
I was luck that when I took the RC car apart to find that the h-bridge for the rear wheels were on a seperate pcb. On the front wheel its like a servo but its now pulse width modulated it is a simple H-bidge. The other nice thing is that both h-bridges had pull down resistor. The one thing that I did have to do was change the way the wires for the rear wheels where soldered to the pcb because it was diffrent from the front wheels.
Heres a shot of the connector for the steering. On the connector the red wire is positive the black wire is negative and the yellow and white wires are for controlling the h-bridge.
Heres a shot of the connector for the rear wheels. On this connector the yellow and white wires are the same as on the steering but I'm not useing the red and black wires becasue on the RC tbey were used to send power to the radio reciever. Bu the·proto board is pulling the power straight from the battery.
On the protoboard I used the resistor for the VGA connector to provide some current limiting for the two H-Bridges
And I used the pull ups from the mouse connector to give a bias to the bumper sensores
Heres also some videos of the car in action.
http://s65.photobucket.com/albums/h230/n1elkyfan/Propeller/?action=view¤t=0218091550.flv
http://s65.photobucket.com/albums/h230/n1elkyfan/Propeller/?action=view¤t=0218091551.flv
http://s65.photobucket.com/albums/h230/n1elkyfan/Propeller/?action=view¤t=0218091553.flv
The things I want to do next on this project is to add some encoders to the rear wheel so that it would be possible to better control the speed. I would also like to replace the front bump sensors with some thing like the ping so that it would not have to hit the walls. The other thing I want to do is find away to make it steer better because right now it can change its direction to any large degree.
I'm going to add my code later because it on my computer at my house and I only have internet at my moms.
Code now uploaded
Post Edited (Cole Logan) : 2/20/2009 5:20:35 PM GMT
And it's a really cool application- using computer vision to control the position of a servo!
Here's what my dad did a couple days ago:
- connect a hobby servo to the ProtoBoard, black to ground, red to +5, white to pin 9.
- mount whatever you want on the servo top- he used a pointer, but you could put a camera, a doll's head...
- control the hobby servo with the bs2 object from obex (you could also use the servo32 object)
- drive the servo with the position provided by ViewPort's OpenCV filter. Currently, ViewPort let's you capture video from a webcam, a file, or a Propeller frame grabber- he used a webcam. Then, you can select from a HSV color blob finder, a Viola Jones object finder (great for finding faces), or a Hough circle finder. All provide an x,y, width, height result to the Propeller. For this application he uses just the x position.
Here's the code:
CON _clkmode = xtal1 + pll16x _xinfreq = 5_000_000 OBJ vp : "Conduit" 'transfers data to/from PC qs : "QuickSample" 'samples INA continuously in 1 cog to 20mhz BS2 : "BS2_Functions" ' Create BS2 Object VAR long pwmst[noparse][[/noparse]100] byte pw1,x1 pub findblob|pos,x,y,a vp.config(string("var[img]http://forums.parallax.com/images/smilies/tongue.gif[/img]os,x,y,a")) vp.config(string("dso:view=[noparse][[/noparse]x,y],timescale=1s")) vp.config(string("video:source=webcam0,mode=face,result=pos")) 'use video from the webcam, filter with the face mode, and write packed result to the pos spin variable vp.config(string("start:video")) vp.share(@pos,@a) BS2.start(1,2) cognew(servopwm(@x1),@pwmst) repeat x:=pos & $3ff '0-1023 y:=pos >>10 & $3ff a:=x+y x1:=x/4 '0-255 pub servopwm(x11) ' generate PWM repeat ' for servo pw1:=byte[noparse][[/noparse]x11] BS2.PULSOUT(9,1*500+3*pw1) ' 1-2.5 ms 2us/cnt BS2.pause(25) ' 25 msSee the picture- it shows his setup with a laptop running ViewPort, a webcam, his "Protoboard/IODreamkit", and a servo with a pointer. The bottom row show the servo pointing to different recognized objects. I'll do a video one of these days, everything is done continuously in real time, so if you move one of the objects, the servo follows!
ViewPort v4.1 is now released- it comes with a 30 day free trial...
Hanno
The robot car is very cool.. It appears that you've met the qualifications for the contest. Neat stuff!
The tracking system is also very cool, but in order to qualify can you replace the servo with something else?
Good stuff gang! Keep'em coming!
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Links to other interesting threads:
· Home of the MultiBladeProps (SixBladeProp)
· Prop Tools under Development or Completed (Index)
· Emulators (Micros eg Altair, and Terminals eg VT100) - index
· Search the Propeller forums (via Google)
My cruising website is: ·www.bluemagic.biz
preparing this little game. An easy 32 colors can be achieved easily. [noparse]:)[/noparse]
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
I dont have the time with my other projects, but this is really a great idea OBC. When the contest expires I will post what I thought of - requires no special parts.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Links to other interesting threads:
· Home of the MultiBladeProps (SixBladeProp)
· Prop Tools under Development or Completed (Index)
· Emulators (Micros eg Altair, and Terminals eg VT100) - index
· Search the Propeller forums (via Google)
My cruising website is: ·www.bluemagic.biz
Excluding the idea of using the resistors that are already available on the board for TV, I initially had thought using pencil lead would be an attractive alternative to the TV resistors.
Then I thought using capacitors (home made) that were proportionally ratio'd would work in place of the resistors all together... ehhh sort of works.
My final thought is without using any resistors or capacitors at all... Yup! For "crude" TV you can get away with using 2-pins directly off of the Propeller without any resistors or caps.
You have to play with the colors a bit, and they are not what you would expect them to be, but it does work.
I changed the graphics pin mode to %000 instead of the default %001, and connected the video input to P5, while the video ground is using any I/O pin configured as an Input. Connecting
the video ground to VSS provided too much signal and the video washed out. The small amount of parasitic capacitance on the I/O pin is just enough... did I say capacitance? Ok well I used
a parasitic capacitor from the Propeller IC.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Beau Schwabe
IC Layout Engineer
Parallax, Inc.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
http://www.propgfx.co.uk/forum/·home of the PropGFX Lite
·
Wrap up those projects and post them! I'm doing my shipping Monday or Tuesday and
want to ship these two Protoboards I'm sitting on my desk. [noparse]:)[/noparse]
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
His Prop-controlled RC car is believable that it would be found at grandma's house, and
project certainly meets the qualifications.
Hanno's project is a close second, but his use of a servo disqualified him.
(Sorry, I just can't picture an extra servo at grandma's house, and I've never seen them sold for $.99 (Or less)
Cole, PM me your address and I'll ship two USB Protoboards to you this week!
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
OBC, thanks for the second prize and running this competition!
Hanno
However, I must object a little (when do I not ... lolz) to the notion that a servo would not be found in an RC car that could be found in Granny's garage. No instant replay rule I guess [noparse]:)[/noparse]
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
--Steve
My thoughts were to make a dice display on the TV using a couple of wires to make a switch. Use the switch to count a random number of clocks in the CNT register and do a mod 6, then add 1 to the remainder. I didn't have the time but I did pick up on OBC's hint about the TV object
Thanks again OBC - you make the forum fun
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Links to other interesting threads:
· Home of the MultiBladeProps (SixBladeProp)
· Prop Tools under Development or Completed (Index)
· Emulators (Micros eg Altair, and Terminals eg VT100) - index
· Search the Propeller forums (via Google)
My cruising website is: ·www.bluemagic.biz