KHR3-HV + Gumstix Overo / Fire
KHR3-HV + Gumstix Overo / Fire
by nunogato
Tue Sep 07, 2010 7:08 pm
Hi, I need to connect a Gumstix Fire to a KHR3 and transform the head into a pan-tilt + camera. Gumstix needs to do image processing with a UVC Linux compatible webcam for self localization and football related activities.
I've ordered the KHR3 and now Looking for some help and ideas on how to go about things with the Gumstix
Your thoughts on the following items will be much appreciated:
1) Gumstix needs to remote control the RCB4 maybe leverage the H2H software and use some API (so that gumstix can send high-level commands to the RCB4). - Seems like Chris Vo's work may provide the solution (?):
Thread discussing Chris's work: http://robosavvy.com/forum/viewtopic.php?t=6470
Chris's API: http://bitbucket.org/vo/libkondo4
There's also some Kondo docs with some C# code in Japanese: http://kondo-robot.com/sys/archives/2477
2) LiPo solution - given the KHR3 battery size area, need to find a decent Lipo battery. Tsukomo's Kondo site they recommend TP1320-3SPL but that would give about 10 minutes of robot life with WiFi enabled (?)
3) KHR3's shoulder bracket - can it be attached to the chest/head (instead of the empty head) and allow a 18th servo to serve as the webcam pan/tilt surface (pan servo is already in the chest) ?
4) Can the back pack to allow for additional gumstix with Summit expansion board + 5V regulator? given that Summit regulator cant take the 11V from the LiPo, need to use a regulator board (sparkfun or ebay).
5) Connecting the RCB4 to the Summit/Gumstix can be done either via the serial through-holes or by USB (OTG). RX/TX on the Gumstix are 1.8V meaning i have to level-shift the signal
. seems like the KHR's USB can be connected to the Summit and maybe Chris Vo's library works on Gumstix too.
6) In the future I'd like to control the KHR3 servos without the RCB's involvement. in this case i'll probably need ChrisVo's board or i-Bot's super-board or maybe find a way to bridge (like Billy's SYNC-READ closed loop method for Dynamixel bus) commands between the Gumstix and the servos via the RCB4
Thanks i-Bot for helping with the above and shedding light on the powering issues of daughter boards Pinto vs. Summit as seen in the pictures below:
I've ordered the KHR3 and now Looking for some help and ideas on how to go about things with the Gumstix
Your thoughts on the following items will be much appreciated:
1) Gumstix needs to remote control the RCB4 maybe leverage the H2H software and use some API (so that gumstix can send high-level commands to the RCB4). - Seems like Chris Vo's work may provide the solution (?):
Thread discussing Chris's work: http://robosavvy.com/forum/viewtopic.php?t=6470
Chris's API: http://bitbucket.org/vo/libkondo4
There's also some Kondo docs with some C# code in Japanese: http://kondo-robot.com/sys/archives/2477
2) LiPo solution - given the KHR3 battery size area, need to find a decent Lipo battery. Tsukomo's Kondo site they recommend TP1320-3SPL but that would give about 10 minutes of robot life with WiFi enabled (?)
3) KHR3's shoulder bracket - can it be attached to the chest/head (instead of the empty head) and allow a 18th servo to serve as the webcam pan/tilt surface (pan servo is already in the chest) ?
4) Can the back pack to allow for additional gumstix with Summit expansion board + 5V regulator? given that Summit regulator cant take the 11V from the LiPo, need to use a regulator board (sparkfun or ebay).
5) Connecting the RCB4 to the Summit/Gumstix can be done either via the serial through-holes or by USB (OTG). RX/TX on the Gumstix are 1.8V meaning i have to level-shift the signal
. seems like the KHR's USB can be connected to the Summit and maybe Chris Vo's library works on Gumstix too.
6) In the future I'd like to control the KHR3 servos without the RCB's involvement. in this case i'll probably need ChrisVo's board or i-Bot's super-board or maybe find a way to bridge (like Billy's SYNC-READ closed loop method for Dynamixel bus) commands between the Gumstix and the servos via the RCB4
Thanks i-Bot for helping with the above and shedding light on the powering issues of daughter boards Pinto vs. Summit as seen in the pictures below:
by i-Bot
Thu Sep 09, 2010 6:08 pm
When Limor told me about this project I was very excited. The Kondo robots are fine machines and the new serial servos on the KHR-3 look to be a step ahead of the AX18F.
The problem with Kondo for me has always been the lack of support in the English language. But a KHR3 with Gumstix sounds worth the translation effort and should be able to compete with Robotis GP and Darwin-LC.
The problem with Kondo for me has always been the lack of support in the English language. But a KHR3 with Gumstix sounds worth the translation effort and should be able to compete with Robotis GP and Darwin-LC.
by i-Bot
Fri Sep 10, 2010 4:10 pm
I took a look at the ability of the Summit interface board for the Gumstix to support higher input voltages.
They use the the Texas TPS62111 regulator which is specified up to 17V input, but appear to use only 10V capacitors. To allow a direct Lipo input, you will need to replace C43 as described on the schematic. C42, is not mentioned, so is probably OK.
http://pubs.gumstix.com/boards/SUMMIT/P ... B30001.pdf
C43 is 10uF ceramic in 805 smd package. Possible replacement is:
http://uk.farnell.com/murata/grm21br61e ... dp/1735530
This a 25V capacitor in same package.
No other components need to be changed.
They use the the Texas TPS62111 regulator which is specified up to 17V input, but appear to use only 10V capacitors. To allow a direct Lipo input, you will need to replace C43 as described on the schematic. C42, is not mentioned, so is probably OK.
http://pubs.gumstix.com/boards/SUMMIT/P ... B30001.pdf
C43 is 10uF ceramic in 805 smd package. Possible replacement is:
http://uk.farnell.com/murata/grm21br61e ... dp/1735530
This a 25V capacitor in same package.
No other components need to be changed.
by chrisvo
Sat Sep 11, 2010 5:34 pm
Hi all, sorry I'm late to the discussion.
This architecture looks similar to what I am setting up now. I am using a IGEPv2 board with the KHR-3HV. However, I do not currently involve the RCB-4, I control the servos directly via ICS3.
I have used Gumstix to control both KHR-1HV and KHR-3HV via the RCB boards. For 3HV, my libkondo4 works on Gumstix, but as I mention in the documentation, some modifications need to be made to the RX/TX commands and init so that you can use other UART instead of the FTDI-serial, I use the HWUART on the Gumstix. There are many reasons libftdi was adopted in libkondo4 - it's faster (supports high-speed serial), easier, generally more reliable, and avoids dealing with device filenames.
I'm still adding more functionality to libkondo4; the documentation finally came out in Japanese but I have not had a chance to look through it and properly implement the protocol. I recently added just a touch of direct-servo-control support though.
Please note that you will need some circuitry not just to level shift but also to invert the logic of the signal to connect the UART on your microcontroller. RCB-4 uses 5V logic, idle low. The Gumstix I believe uses 1.8V idle high.
Battery - I personally use a 2200 mAh 11.1v Li-Ion (not Li-Poly) battery which costs $20 USD each and easily lasts for a full 1 hour with all the servos running, WiFi, and 2 processor cards (SRV-1). Li-ion chargers are cheap too. However, it doesn't really fit anywhere on the stock KHR3 body. As a rule of thumb, the KHR-3 draws around 1A average, usually less when you are standing still, and sometimes spikes beyond 2A when running a particularly strenuous motion (pushing the servos too hard). That is very rare, and if you can provide solid 2A you should be fine. Actually, I would put a resettable fuse in there to prevent drawing more than 2A just because I have had the experience of an exploding RCB-4 before...
I also did have to modify the torso to make room for these things. Here's what mine looks like (I simply cut rectangles out of 6061 aluminum because I do not have craft skills to do anything more interesting)
http://www.flickr.com/photos/christophervo/4610291401/
However, if you look at that picture there are three screws at the bottom connecting the legs assembly. Those screws broke eventually and my friend used threaded steel rods to bolt the body together later on. You can kind of see that here:
http://www.flickr.com/photos/christophe ... 081021455/
This architecture looks similar to what I am setting up now. I am using a IGEPv2 board with the KHR-3HV. However, I do not currently involve the RCB-4, I control the servos directly via ICS3.
I have used Gumstix to control both KHR-1HV and KHR-3HV via the RCB boards. For 3HV, my libkondo4 works on Gumstix, but as I mention in the documentation, some modifications need to be made to the RX/TX commands and init so that you can use other UART instead of the FTDI-serial, I use the HWUART on the Gumstix. There are many reasons libftdi was adopted in libkondo4 - it's faster (supports high-speed serial), easier, generally more reliable, and avoids dealing with device filenames.
I'm still adding more functionality to libkondo4; the documentation finally came out in Japanese but I have not had a chance to look through it and properly implement the protocol. I recently added just a touch of direct-servo-control support though.
Please note that you will need some circuitry not just to level shift but also to invert the logic of the signal to connect the UART on your microcontroller. RCB-4 uses 5V logic, idle low. The Gumstix I believe uses 1.8V idle high.
Battery - I personally use a 2200 mAh 11.1v Li-Ion (not Li-Poly) battery which costs $20 USD each and easily lasts for a full 1 hour with all the servos running, WiFi, and 2 processor cards (SRV-1). Li-ion chargers are cheap too. However, it doesn't really fit anywhere on the stock KHR3 body. As a rule of thumb, the KHR-3 draws around 1A average, usually less when you are standing still, and sometimes spikes beyond 2A when running a particularly strenuous motion (pushing the servos too hard). That is very rare, and if you can provide solid 2A you should be fine. Actually, I would put a resettable fuse in there to prevent drawing more than 2A just because I have had the experience of an exploding RCB-4 before...
I also did have to modify the torso to make room for these things. Here's what mine looks like (I simply cut rectangles out of 6061 aluminum because I do not have craft skills to do anything more interesting)
http://www.flickr.com/photos/christophervo/4610291401/
However, if you look at that picture there are three screws at the bottom connecting the legs assembly. Those screws broke eventually and my friend used threaded steel rods to bolt the body together later on. You can kind of see that here:
http://www.flickr.com/photos/christophe ... 081021455/
by limor
Sat Sep 11, 2010 8:52 pm
Hi chrisvo
thanks for your feedback.
can you please specify how you level-shifted and inverted the signal from the UART? did you develop a board?
With Gumstix, which daughter board did you use ?
With IGEPv2, which version of the board did you use and did it fit onto the KHR3 ?
When you control the servos without the use of the RCB4, what speed did you set the servos to run and how many serial buses did you use and do you have any code you can share?
We've received the KHR3 and will measure the size of the battery on the back of the robot. hopefully a decent LiPo can be fitted into there without having to modify the structure. I was thinking of using a second small Lipo to power the gumstix.
I've been in touch with IGEP regarding their new gumstix-like board, which comes with USB interface. it will be out in October.
thanks!
Limor
thanks for your feedback.
can you please specify how you level-shifted and inverted the signal from the UART? did you develop a board?
With Gumstix, which daughter board did you use ?
With IGEPv2, which version of the board did you use and did it fit onto the KHR3 ?
When you control the servos without the use of the RCB4, what speed did you set the servos to run and how many serial buses did you use and do you have any code you can share?
We've received the KHR3 and will measure the size of the battery on the back of the robot. hopefully a decent LiPo can be fitted into there without having to modify the structure. I was thinking of using a second small Lipo to power the gumstix.
I've been in touch with IGEP regarding their new gumstix-like board, which comes with USB interface. it will be out in October.
thanks!
Limor
by chrisvo
Sun Sep 12, 2010 11:28 pm
With Gumstix, which daughter board did you use ?
RoboStix
can you please specify how you level-shifted and inverted the signal from the UART? did you develop a board?
This is how we communicate from RoboStix UART (3.3V) to RCB-4.
With IGEPv2, which version of the board did you use and did it fit onto the KHR3 ?
Rev.C, it fits in my modified robot chassis. It does not fit on a stock 3HV, the chest is too small.
When you control the servos without the use of the RCB4, what speed did you set the servos to run and how many serial buses did you use and do you have any code you can share?
They currently run 115200, which seems sufficient.
I have 2 serial busses, one for the left-side servos, one for the right-side servos.
I do have experimental code I can share, but I haven't had a chance to commit it to libkondo4 project. Basically I created an ics.c and ics.h which implements the important parts of ICS 3.0 (everything except for reading/writing the servo firmware)
I've been in touch with IGEP regarding their new gumstix-like board, which comes with USB interface. it will be out in October.
I am interested in their gumstix-sized platform as well...
by i-Bot
Mon Sep 13, 2010 11:08 am
The small IGEP board does look very interesting, but it will depend on whether they or someone else makes a good expansion board for robotics.
Their proposed expansion is large and has a lot on features not required for robotics. Gumstix do seem to have thought about robot application in their range of expansion boards.
Their proposed expansion is large and has a lot on features not required for robotics. Gumstix do seem to have thought about robot application in their range of expansion boards.
by nunogato
Wed Sep 15, 2010 1:24 pm
Already finished to assemble the robot.
To make the pan/tilt I had to use some parts from the leg (now need to order more to finish the robot) to do this I needed:
1 x Servo
1 x YHR-A1-1
1 x YHR-A1-2
1 x YHR-A1-3
1 x YHR-A1-4
And some screws.
The only parts needed to order are the bold ones, the kit comes with spare screws and some spare YHR-A1-4
The pan tilt head works perfectly, here are some photos and the video
I was measuring the space to check where to fit the gumstix and the batteries.
To power the Robot I found this LiPo 1300mAh 11.1v (71 x 34 x 24mm) battery that fits exactly inside the robot (I made some cardboard cubes with the same size to check where it fits).
To power the gumstix this 460mAh 7.4v (52 x 30 x 8mm) it's really small, can fit in the chest or in the back pack. In the next photo i'ts glued with some tape
The problem with the LiPo batteries now is the charger. Need to search for it.
The next step is find some space to fit the gumstix with Pinto/Summit board and all the cables. One option is remove the battery from the inside of the robot and put there the boards. The battery can then goes under the backpack
To make the pan/tilt I had to use some parts from the leg (now need to order more to finish the robot) to do this I needed:
1 x Servo
1 x YHR-A1-1
1 x YHR-A1-2
1 x YHR-A1-3
1 x YHR-A1-4
And some screws.
The only parts needed to order are the bold ones, the kit comes with spare screws and some spare YHR-A1-4
The pan tilt head works perfectly, here are some photos and the video
phpBB [media]
I was measuring the space to check where to fit the gumstix and the batteries.
To power the Robot I found this LiPo 1300mAh 11.1v (71 x 34 x 24mm) battery that fits exactly inside the robot (I made some cardboard cubes with the same size to check where it fits).
To power the gumstix this 460mAh 7.4v (52 x 30 x 8mm) it's really small, can fit in the chest or in the back pack. In the next photo i'ts glued with some tape
The problem with the LiPo batteries now is the charger. Need to search for it.
The next step is find some space to fit the gumstix with Pinto/Summit board and all the cables. One option is remove the battery from the inside of the robot and put there the boards. The battery can then goes under the backpack
by nunogato
Mon Sep 20, 2010 5:07 pm
Spaces within KHR3HV
In the two pictures below you can see where it is possible to insert batteries and electronics.
1) Back-pack top side (above the RCB4 cables)
2) Back-pack side - involves removing one of the two plastic part that are screwed to the sides of the RCB4. They don't serve a purpose other than holding the gyros and accelerometer. Only one is really needed and the other can be removed leaving space for a small LiPo battery.
3) Inside Cavity
4) Chest cavity - not much space but can hold a small battery
5) Below the back-pack, on the external part of the robot ("The BUM") - perfect place for a 1300mah LiPo
Using 2 LiPo's - 11.1V and 7.4V
If we use two batteries, it solves the problem of Summit board not accepting the 11.1V due to a 10V capacitor (even though the regulator can accept more). The diagram below shows the new solution.
11.1V LiPo - https://www.sparkfun.com/commerce/produ ... ts_id=9702
7.4V LiPo - https://www.sparkfun.com/commerce/produ ... ts_id=9701
(The ppt file is linked below so if you wish to suggest an alternative, you can use the ppt)
http://robosavvy.com/Builders/nunogato/KHR-Summit-Gumstix1.ppt
Current thinking regarding the various options
<table border="1" cellpadding="5" cellspacing="0"><tr><td></td><td>Summit</td><td>Pinto</td><td>IGEP</td></tr><tr><td>power</td><td>Accepts up to 10V (TPS62111accepts up to 17V but capacitor on board only accepts 10V)</td><td>Accepts up to 10V (TPS62111accepts up to 17V but capacitor on board only accepts 10V)</td><td>Powered by USB</td></tr><tr><td>External wifi dongle (cheap)</td><td>Can connect directly via USBhost. (Standard 500mah rating)</td><td>Requires powered USB hub</td><td>n/a (includes wifi)</td></tr><tr><td>webcam</td><td>Can connect directly via USBhost. (Standard 500mah rating)</td><td>Requires powered USB hub</td><td>Requires powered USB hub</td></tr><tr><td>usb2serial</td><td>Can connect directly via USBhost or OTG (rated 100mah)</td><td>Requires USB hub</td><td>Requires USB hub</td></tr><tr><td>Direct Serial connection</td><td>level shift + inversion(sparkfun BOB-08745 can level-shift but no inversion)</td><td>level shift + inversion(sparkfun BOB-08745 can level-shift but no inversion)</td><td>level shift + inversion(sparkfun BOB-08745 can level-shift but no inversion)</td></tr><tr><td>SD card</td><td>onboard the gumstix</td><td>onboard the gumstix</td><td>onboard the IGEP</td></tr><tr><td>space on robot</td><td>Has to go into the back-packabove the RCB4 cables</td><td>Can go into the internal cavityof the robot or into the back-pack above the RCB4 cables</td><td>Can go into the internal cavityof the robot or into the back-pack above the RCB4 cables</td></tr><tr><td>usb plug direction</td><td>Vertical USB mini-A USB hostmust use angled USB connector</td><td>Vertical USB mini-AB USB OTGmust use angled USB connector</td><td>Vertical mini-AB USB OTG</td></tr><tr><td>11V Lipo battery for servos andRCB4</td><td>Can go in internal cavity or onrobot bum</td><td>Can go in internal cavity or onrobot bum</td><td>Can go in internal cavity or onrobot bum</td></tr><tr><td>7.4V 460mah LiPo for linux (fitsin front chest or on side of RCB4)</td><td>Can power the Summit. Gumstixrated 250mah w/o wifi. can it power the wifi+ webcam ?</td><td>Can power the Summit. Gumstixrated 250mah w/o wifi. can it power the wifi+ webcam ?</td><td>Can power the IGEP, rated at450mah max. With wifi . can it power webcam ?</td></tr></table>
Table of measurements
<table border="1" cellpadding="5" cellspacing="0"><tr><td></td><td width="150">L (cm)</td><td width="150">W (cm)</td><td width="150">H (cm)</td></tr><tr><td>Internal Cavity</td><td>7.1</td><td>4.2</td><td>2.4</td></tr><tr><td>Chest Cavity</td><td>7.1 (7.6 w/o corners)</td><td>3.5 (5.2 w/o corners)</td><td>1.2</td></tr><tr><td>Backpack (top)</td><td>9.6</td><td>5</td><td>1.5</td></tr><tr><td>Battery</td><td>7.1</td><td>3.4</td><td>2.4</td></tr><tr><td>Summit+Gumstix</td><td>8</td><td>3.9</td><td>1</td></tr><tr><td>IGEP</td><td>7</td><td>1.8</td><td>0.7</td></tr></table>
In the two pictures below you can see where it is possible to insert batteries and electronics.
1) Back-pack top side (above the RCB4 cables)
2) Back-pack side - involves removing one of the two plastic part that are screwed to the sides of the RCB4. They don't serve a purpose other than holding the gyros and accelerometer. Only one is really needed and the other can be removed leaving space for a small LiPo battery.
3) Inside Cavity
4) Chest cavity - not much space but can hold a small battery
5) Below the back-pack, on the external part of the robot ("The BUM") - perfect place for a 1300mah LiPo
Using 2 LiPo's - 11.1V and 7.4V
If we use two batteries, it solves the problem of Summit board not accepting the 11.1V due to a 10V capacitor (even though the regulator can accept more). The diagram below shows the new solution.
11.1V LiPo - https://www.sparkfun.com/commerce/produ ... ts_id=9702
7.4V LiPo - https://www.sparkfun.com/commerce/produ ... ts_id=9701
(The ppt file is linked below so if you wish to suggest an alternative, you can use the ppt)
http://robosavvy.com/Builders/nunogato/KHR-Summit-Gumstix1.ppt
Current thinking regarding the various options
<table border="1" cellpadding="5" cellspacing="0"><tr><td></td><td>Summit</td><td>Pinto</td><td>IGEP</td></tr><tr><td>power</td><td>Accepts up to 10V (TPS62111accepts up to 17V but capacitor on board only accepts 10V)</td><td>Accepts up to 10V (TPS62111accepts up to 17V but capacitor on board only accepts 10V)</td><td>Powered by USB</td></tr><tr><td>External wifi dongle (cheap)</td><td>Can connect directly via USBhost. (Standard 500mah rating)</td><td>Requires powered USB hub</td><td>n/a (includes wifi)</td></tr><tr><td>webcam</td><td>Can connect directly via USBhost. (Standard 500mah rating)</td><td>Requires powered USB hub</td><td>Requires powered USB hub</td></tr><tr><td>usb2serial</td><td>Can connect directly via USBhost or OTG (rated 100mah)</td><td>Requires USB hub</td><td>Requires USB hub</td></tr><tr><td>Direct Serial connection</td><td>level shift + inversion(sparkfun BOB-08745 can level-shift but no inversion)</td><td>level shift + inversion(sparkfun BOB-08745 can level-shift but no inversion)</td><td>level shift + inversion(sparkfun BOB-08745 can level-shift but no inversion)</td></tr><tr><td>SD card</td><td>onboard the gumstix</td><td>onboard the gumstix</td><td>onboard the IGEP</td></tr><tr><td>space on robot</td><td>Has to go into the back-packabove the RCB4 cables</td><td>Can go into the internal cavityof the robot or into the back-pack above the RCB4 cables</td><td>Can go into the internal cavityof the robot or into the back-pack above the RCB4 cables</td></tr><tr><td>usb plug direction</td><td>Vertical USB mini-A USB hostmust use angled USB connector</td><td>Vertical USB mini-AB USB OTGmust use angled USB connector</td><td>Vertical mini-AB USB OTG</td></tr><tr><td>11V Lipo battery for servos andRCB4</td><td>Can go in internal cavity or onrobot bum</td><td>Can go in internal cavity or onrobot bum</td><td>Can go in internal cavity or onrobot bum</td></tr><tr><td>7.4V 460mah LiPo for linux (fitsin front chest or on side of RCB4)</td><td>Can power the Summit. Gumstixrated 250mah w/o wifi. can it power the wifi+ webcam ?</td><td>Can power the Summit. Gumstixrated 250mah w/o wifi. can it power the wifi+ webcam ?</td><td>Can power the IGEP, rated at450mah max. With wifi . can it power webcam ?</td></tr></table>
Table of measurements
<table border="1" cellpadding="5" cellspacing="0"><tr><td></td><td width="150">L (cm)</td><td width="150">W (cm)</td><td width="150">H (cm)</td></tr><tr><td>Internal Cavity</td><td>7.1</td><td>4.2</td><td>2.4</td></tr><tr><td>Chest Cavity</td><td>7.1 (7.6 w/o corners)</td><td>3.5 (5.2 w/o corners)</td><td>1.2</td></tr><tr><td>Backpack (top)</td><td>9.6</td><td>5</td><td>1.5</td></tr><tr><td>Battery</td><td>7.1</td><td>3.4</td><td>2.4</td></tr><tr><td>Summit+Gumstix</td><td>8</td><td>3.9</td><td>1</td></tr><tr><td>IGEP</td><td>7</td><td>1.8</td><td>0.7</td></tr></table>
by chrisvo
Tue Sep 21, 2010 3:48 am
I like it! I have the IGEPv2 board and I can take pictures of it with the 3HV backpack to give you an idea if it would fit in there...
On a slightly related note, for our robot's power switches, I've been trying to find a place to buy some small subminiature rocker switches. They just don't seem to make subminiature rocker switches in the USA. A perfect example of what I want is the KCD11 rocker switch that's on the Robotis CM-700 (here's a picture): http://imgur.com/EummM.jpg
Anyone know where I can get something like that? I know I can buy these from China in quantities of like 10,000 but I only need about 20 of them...
On a slightly related note, for our robot's power switches, I've been trying to find a place to buy some small subminiature rocker switches. They just don't seem to make subminiature rocker switches in the USA. A perfect example of what I want is the KCD11 rocker switch that's on the Robotis CM-700 (here's a picture): http://imgur.com/EummM.jpg
Anyone know where I can get something like that? I know I can buy these from China in quantities of like 10,000 but I only need about 20 of them...
by i-Bot
Tue Sep 21, 2010 9:56 am
Chris,
I had problems finding a small switch too.
In the end this was the best I could find in the small size from a low volume distributor (Newark through Farnell).
http://www.newark.com/cherry/prk22j5bbb ... tt=25k9380
It is not DC rated, but works fine for me.
I had problems finding a small switch too.
In the end this was the best I could find in the small size from a low volume distributor (Newark through Farnell).
http://www.newark.com/cherry/prk22j5bbb ... tt=25k9380
It is not DC rated, but works fine for me.
by i-Bot
Tue Sep 21, 2010 10:13 am
Nunogato,
I would avoid the USB hub unless you are sure you have the right one. I have been doing some tests and many USB 2.0 give lots errors, slow frame rates, or fail to work. Especially, some give frame errors on large isochronous packets (video). I suspect this may be due to buffer sizes in the hub chip. Some other errors may be due to the poor quality construction of some hubs.
I have success (no errors) with hubs based on FE1.1s chip and the USB2514 chip.
This has the FE1.1s chip (or at least mine did !):
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0409815541
If you use the Overo fire, the WLAN in on SPI I think. So you have enough ports without hub.
We can do a simple level convert/invert if you need it.
I would avoid the USB hub unless you are sure you have the right one. I have been doing some tests and many USB 2.0 give lots errors, slow frame rates, or fail to work. Especially, some give frame errors on large isochronous packets (video). I suspect this may be due to buffer sizes in the hub chip. Some other errors may be due to the poor quality construction of some hubs.
I have success (no errors) with hubs based on FE1.1s chip and the USB2514 chip.
This has the FE1.1s chip (or at least mine did !):
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0409815541
If you use the Overo fire, the WLAN in on SPI I think. So you have enough ports without hub.
We can do a simple level convert/invert if you need it.
by nunogato
Tue Sep 21, 2010 1:03 pm
where can i find the smallest UVC webcam ?
it needs to fit onto that small pan-tilt servo.
As for plugging the USB cable into the Summit, the idea is to use an angled USB cable connector although so far we haven't found a short cables of type [Female-A to Mini-A], [Female-A to Mini-B], therefore the solution would be to DIY it . Buy a standard Female-A thin usb cable, cut it short and solder the 4 wires to a Mini-A and Mini-B connector.
any other ideas or opinions ?
it needs to fit onto that small pan-tilt servo.
As for plugging the USB cable into the Summit, the idea is to use an angled USB cable connector although so far we haven't found a short cables of type [Female-A to Mini-A], [Female-A to Mini-B], therefore the solution would be to DIY it . Buy a standard Female-A thin usb cable, cut it short and solder the 4 wires to a Mini-A and Mini-B connector.
any other ideas or opinions ?
by i-Bot
Tue Sep 21, 2010 2:27 pm
I don't have a complete answer on the camera.
I first tried a cheap UVC camera from here:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0484107927
It was recognised OK as a USB 2.0 Hgh speed UVC camera, but did not work with the MJPEG-Streamer software. It does seem to work in YUV, which is probably what you want for image capture and analysis. The other thing I did not like were the LEDs. They don't really work, so are a waste of space and power.
I eventually got this Logitech 3000 for Business (SKU 960-000310):
http://www.amazon.co.uk/Logitech-960-00 ... 360&sr=8-1
This does the MJPEG streaming OK. Did not try on YUV though
For the cable, all the webcam cables are too long, so I suggest to cut it down and add your right angle connector.
I first tried a cheap UVC camera from here:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0484107927
It was recognised OK as a USB 2.0 Hgh speed UVC camera, but did not work with the MJPEG-Streamer software. It does seem to work in YUV, which is probably what you want for image capture and analysis. The other thing I did not like were the LEDs. They don't really work, so are a waste of space and power.
I eventually got this Logitech 3000 for Business (SKU 960-000310):
http://www.amazon.co.uk/Logitech-960-00 ... 360&sr=8-1
This does the MJPEG streaming OK. Did not try on YUV though
For the cable, all the webcam cables are too long, so I suggest to cut it down and add your right angle connector.
by i-Bot
Wed Sep 22, 2010 12:57 pm
I opened up both cameras to check the internals.
The Cheap YUV camera has a single board with lens attched to board and not to case. The wires for the microphone, USB, and mini DIN for audio are soldered to board. Overall size of board inc wires and lens is 30 x 25 x 20 mm. LEDS are easy to remove.
The Logitech is also single board with lens attached to board only. Wires for USB, microphone and push buttone are via plugs and sockets. Overall size of board inc connectors and lens is 38 x 31 x 25 mm.
The Cheap YUV camera has a single board with lens attched to board and not to case. The wires for the microphone, USB, and mini DIN for audio are soldered to board. Overall size of board inc wires and lens is 30 x 25 x 20 mm. LEDS are easy to remove.
The Logitech is also single board with lens attached to board only. Wires for USB, microphone and push buttone are via plugs and sockets. Overall size of board inc connectors and lens is 38 x 31 x 25 mm.