RoboPi+Create

Rsadeika

I just wrote a nice long beginning post and It got lost, not sure what happened, but I guess you get logged out if you are writing a post too long, I think. So I guess I will have to piece meal this thread. I will probably be using the RoboPi to replace the Activity board that I now I have on my iRobot Create chassis. I started this thread so as not to clutter up the RoboPi thread in the other forum. Now I feel like I am under some time constraint while writing this post, I feel rushed, more later...

Ray

Rsadeika

Not being sure as to how much time I have to write this post, before I get logged off, here is another installment. My setup right now is I have a Create with the re-chargeable battery, the docking station,and an Activity Board as the robot controller, unfortunately I have run out of control and processing power with this setup, hence the change over to RoboPi. I hope there is a pre-assembled RoboPi board available, my soldering skills are horrible or maybe its my eye sight that is starting to fail. No excuses, just getting old.

Well I guess I beat the logged off period. Next installment soon...

Ray

Bill Henning

Hi Ray - great idea to make this thread for your bot!

I'll keep an eye on it to answer any questions you may have, I am looking forward to seeing what you will do with your Create and a RoboPi.

Looks like the DB-25 socket on the Create can supply 500mA, which is plenty to run RoboPi, and you could use two of the 5V tolerant servo headers to supply RX and TX to the Create. That will let you use a PropPlug to program/debug RoboPi, with another serial (say Tx=P22, Rx=P23) for a second serial connection, to be used to communicate with the Create.

I do have a limited number of assembled and tested boards available, as several others wanted RoboPi... but did not want to solder

Email me at the address in my signature.

Rsadeika

Looks like the DB-25 socket on the Create can supply 500mA, which is plenty to run RoboPi,...

Since I plan on using the model-b RPi with a camera module and a WiFi module, I have read that probably the power supply should be 1A, and some have suggested possibly 2A. The biggest concern I have right now is how to minimize the DB-25 setup that I am using right now. I found a prepared DB-25 ribbon cable that I had, unfortunately it is about three feet long which is attached to a DB-25 break out board, this setup takes up a lot of room in the cargo bay. So I need some suggestions as to how too minimize that setup, any ideas? I am not into making any boards, but a board with a DB-25 connection on it would minimize a lot of excess wire. I know that iRobot sells an expansion module with a processor in it which fits on the ledge where the DB-25 connection is, it is a nice setup, but the processor is way to underpowered to do anything that is useful IMO.

Ray

Bill Henning

Rsadeika wrote: »

Since I plan on using the model-b RPi with a camera module and a WiFi module, I have read that probably the power supply should be 1A, and some have suggested possibly 2A.

I agree. Sorry, for some reason I thought you would run RoboPi stand-alone...

I use USB powerpacks that have a 2.1A output to power the RoboPi + Raspberry Pi + Wifi on my bots, I am sure there would be more than enough power for a camera module as well.

Rsadeika wrote: »

The biggest concern I have right now is how to minimize the DB-25 setup that I am using right now. I found a prepared DB-25 ribbon cable that I had, unfortunately it is about three feet long which is attached to a DB-25 break out board, this setup takes up a lot of room in the cargo bay. So I need some suggestions as to how too minimize that setup, any ideas?

I'd probably do one of the following:

- get an ribbon cable like yours, only a lot shorter (6" or less) with an IDC-DB25 connector on one end, and a 26 pin female header on the other, and run that to a prototyping board, wiring that to RoboPi via two three-pin servo extension cords - this also gives you an expansion area

- get a solder-lug terminal DB-25-M, and use three one pin male-to-female dupont cables, soldering the male end to the male DB-25 connector, and run Tx, Rx, GND to the servo header on RoboPi - this is the easiest / simplest solution

- get a db25 breakout board from Ebay

Rsadeika wrote: »

I am not into making any boards, but a board with a DB-25 connection on it would minimize a lot of excess wire. I know that iRobot sells an expansion module with a processor in it which fits on the ledge where the DB-25 connection is, it is a nice setup, but the processor is way to underpowered to do anything that is useful IMO.

Ray

I like the Create... I don't like their command module - which appears to be out of stock anyway.

Hope this helps!

Rsadeika

Thanks for the ideas Bill.

I have had my Create for a very long time, and I have tried all kinds of ways to give it lots of processing power. In fact I even tried mounting a mini-itx board, but the problem was the power supply, needed a 12V battery which creates a problem of storage in the cargo bay, let alone a re-charging setup. But the one thing that makes the Create a very useful robot is the re-chargeable battery and the docking station where it gets re-charged automatically, plus it has some built in docking functions. Those are two of the most important things that a robot should have, no matter what size it is IMO.

Ray

Rsadeika

This morning I was looking at the "RoboPi-User-Manual", can I make a suggestion? I noticed that there is no discussion about the power requirements, for instance, RoboPi in a stand-alone configuration, how do you power the board? what kind of power source 5V or 9V or 16V or? Do you use the pins in the upper left side of the board? And a couple of paragraphs for describing the power requirements when you attach the Raspbery Pi. What are the power attachment points the mini-din plug or the GPIO pins, I guess a bold statement "5V ONLY". Does this power both boards? ..., etc.

I was also looking at, according to the manual, how I would make the connection to the Create, which I usually use the default 57600 BAUD. You have the "SENSOR" pins, but how do you setup the BAUD rate for a selected Rx and Tx pins? I did not see any function for that purpose, in the manual. Since I have created some functions, in PropGCC, for working with the Create, I am now considering using C as the programming language, since I already have functions developed in C. Portability at its best. Just a few observations this morning...

Ray

Bill Henning

Hi Ray,

You are most welcome

Look for a "Pico-PSU" for your mini-ITX board, that should work for you.

I might get the charging dock + battery pack later, that would be very useful - I did not get one now as I think I still have a Roomba dock + battery somewhere. For now, I'll load 12x NiMh, that I will charge externally, and I did buy a couple of extra AA battery shells.

Rsadeika wrote: »

Thanks for the ideas Bill.

I have had my Create for a very long time, and I have tried all kinds of ways to give it lots of processing power. In fact I even tried mounting a mini-itx board, but the problem was the power supply, needed a 12V battery which creates a problem of storage in the cargo bay, let alone a re-charging setup. But the one thing that makes the Create a very useful robot is the re-chargeable battery and the docking station where it gets re-charged automatically, plus it has some built in docking functions. Those are two of the most important things that a robot should have, no matter what size it is IMO.

Ray

Bill Henning

Rsadeika wrote: »

This morning I was looking at the "RoboPi-User-Manual", can I make a suggestion? I noticed that there is no discussion about the power requirements, for instance, RoboPi in a stand-alone configuration, how do you power the board? what kind of power source 5V or 9V or 16V or? Do you use the pins in the upper left side of the board? And a couple of paragraphs for describing the power requirements when you attach the Raspbery Pi. What are the power attachment points the mini-din plug or the GPIO pins, I guess a bold statement "5V ONLY". Does this power both boards? ..., etc.

Suggestions are always welcome!

Did you see p.16 of the user manual?

Or p.18 of the build manual?

I talk about how to power RoboPi for stand operation there. That page is due to be updated in the future (including diagrams), but the basic information is there.

Rsadeika wrote: »

I was also looking at, according to the manual, how I would make the connection to the Create, which I usually use the default 57600 BAUD. You have the "SENSOR" pins, but how do you setup the BAUD rate for a selected Rx and Tx pins? I did not see any function for that purpose, in the manual. Since I have created some functions, in PropGCC, for working with the Create, I am now considering using C as the programming language, since I already have functions developed in C. Portability at its best. Just a few observations this morning...

Ray

For the moment, you could use a USB-Serial cable to connect the Create to the Pi on a different serial port.

I was planning on adding a "slave serial device" capability to the RoboPi firmware, I'll see if I can add that sooner rather than later.

For my Create, I plan on using P22 & P23 for TX, RX respectively (when I get around to it)

Bill

Rsadeika

I was planning on adding a "slave serial device" capability to the RoboPi firmware, I'll see if I can add that sooner rather than later.

For my Create, I plan on using P22 & P23 for TX, RX respectively (when I get around to it)

For your "slave serial device", what baud rates will you make available? You mention P22 & P23, but it will work with all of the "SENSOR" pins, correct? Out of curiosity, how are you using the RPi to, in essence, program the Propeller? With your setup will you be able to setup an interactive C program to control the robot? I guess I am not sure I understand how you are using the RPi to program the Propeller? Will you be adding some "RoboPi firmware" to use the Propeller COGs, and will you be adding some kind C threading support, may tied too the COG(s)? Or am I getting to advanced here with what the RoboPi will be capable of doing?

Hmm, I am not sure how I missed p16 in the user manual, maybe it was to early in the morning.

Ray

Bill Henning

Rsadeika wrote: »

For your "slave serial device", what baud rates will you make available?

Depends on what the quad serial port driver supports, as that is what I am planning to support, I suspect it will top out at 115.2kbps.

Rsadeika wrote: »

You mention P22 & P23, but it will work with all of the "SENSOR" pins, correct?

It will work on P0...P23, I mentioned P22&P23 as that is what I am planning to use for my Create based robot.

Rsadeika wrote: »

Out of curiosity, how are you using the RPi to, in essence, program the Propeller?

Older SimpleIDE+propgcc recompiled for the Pi, with a modified (by Heater) older propeller load. There is a new version I intend to migrate to over the next few weeks.

Rsadeika wrote: »

With your setup will you be able to setup an interactive C program to control the robot?

Yes, I do that now. Please refer to the user manual, you will see Pi C demo code that talks to the firmware on RoboPi.

Rsadeika wrote: »

I guess I am not sure I understand how you are using the RPi to program the Propeller?

I can, with properller-load, however you can just use a PropPlug to program the eeprom image into RoboPi before stacking it on the Pi, and use the RoboPiLib.o which implements my API (see user manual)

Rsadeika wrote: »

Will you be adding some "RoboPi firmware" to use the Propeller COGs,

Already done, please see product page and user manual

Rsadeika wrote: »

and will you be adding some kind C threading support, may tied too the COG(s)?

RoboPiLib is currently not thread-safe, but could be made to be thread safe fairly easily on the Pi.

Rsadeika wrote: »

Or am I getting to advanced here with what the RoboPi will be capable of doing?

I think you need to take a deep breath, and read the user manual so you can see the capabilities RoboPi provides right now (more capabilities coming over time)

There are basically four use cases for RoboPi:

1) RoboPi+Pi, using RoboPi firmware: basically an intelligent peripheral, supporting only the API functions as documented

2) RoboPi+Pi, advanced user - custom firmware written by the user

3) RoboPi stand-alone (no Pi) - can use RoboPiObj API to quickly write bot code

4) RoboPi stand-alone with custom code - whatever you write

Rsadeika wrote: »

Hmm, I am not sure how I missed p16 in the user manual, maybe it was to early in the morning.

Ray

No worries!

Hope this helps,

Bill

Rsadeika

Thanks Bill, that helps. I want to make sure I completely understand what I will be getting myself into, before I start spending time and money on a new direction of robot controller. I have high hopes of coming up with a fairly decent autonomous robot using the Create chassis, I do not want to end up scratching my head, at some point, trying to figure why or how a ran out of controller resources this time around. This should be way better than trying to mount a mini-itx to the robot, I hope, or am I deceiving myself?

Ray

Bill Henning

You are welcome Ray, I am glad to help!

mini-itx would give you more processing power, but also more headaches including significantly more difficult power subsystem and much higher rate of battery drain

fyi, sooner or later I will release Ubuntu 32 bit and 64 bit RoboPiLib's, as that is actually where I develop the library so even a mini-itx board could use RoboPi for servo/sensor control.

Bill

Rsadeika wrote: »

Thanks Bill, that helps. I want to make sure I completely understand what I will be getting myself into, before I start spending time and money on a new direction of robot controller. I have high hopes of coming up with a fairly decent autonomous robot using the Create chassis, I do not want to end up scratching my head, at some point, trying to figure why or how a ran out of controller resources this time around. This should be way better than trying to mount a mini-itx to the robot, I hope, or am I deceiving myself?

Ray

Rsadeika

I just read the Arlo Power Distribution Board (APDB) thread, and I am starting to rethink the use of the Create. I guess the first question would be, can the RoboPi work with the HB-25 Motor Controller? That APDB really creates some great expansion possibilities, I like that you can pick up 5V 1AMP, that would be great for the RPi, I would think? The only thing that would be missing is some kind of auto re-charging scenario for the robot, if it had that... Thinking...

Ray

kwinn

Rsadeika wrote: »

I just wrote a nice long beginning post and It got lost, not sure what happened, but I guess you get logged out if you are writing a post too long, I think. So I guess I will have to piece meal this thread. I will probably be using the RoboPi to replace the Activity board that I now I have on my iRobot Create chassis. I started this thread so as not to clutter up the RoboPi thread in the other forum. Now I feel like I am under some time constraint while writing this post, I feel rushed, more later...

Ray

For long posts I use a word processor to compose it and then copy/paste it to the forum. Avoids frustration. Checking the "Remember me" box also helps.

Bill Henning

Hi Ray,

The APDB looks good, however I'd still power the RoboPi+Pi+WiFi+camera combo from a USB powerpack with a 2.1A output as 1A is not enough for Pi+WiFi.

While I don't have an HB-25 yet (it's on my "To Buy" list), it should work great with RoboPi as it uses servo-style pulses to control direction and speed.

See http://www.parallax.com/sites/default/files/downloads/29144-HB-25-Motor-Controller-V1.2.pdf

Use a separate servo connector for each motor, and it should work with the existing RoboPi firmware.

It would be possible to support the "dual mode" (two HB-25's on one servo connector) however that would require a separate driver in a separate cog, and I'd rather use two pins than use up a cog, so I do not plan on supporting that mode.

Auto-recharge will be a fun sub-project for you

Bill

Rsadeika wrote: »

I just read the Arlo Power Distribution Board (APDB) thread, and I am starting to rethink the use of the Create. I guess the first question would be, can the RoboPi work with the HB-25 Motor Controller? That APDB really creates some great expansion possibilities, I like that you can pick up 5V 1AMP, that would be great for the RPi, I would think? The only thing that would be missing is some kind of auto re-charging scenario for the robot, if it had that... Thinking...

Ray

Rsadeika

Auto-recharge will be a fun sub-project for you

That sounds like a major project, not having any schematics, I do not think there are any provisions for any other type of recharging methods without of course butchering up the board, which I am not capable of doing. It would be kind of interesting to maneuver a robot two prong recharge wire into a wall socket LOL

I also noticed that the Eddie Control Board is a final build, I wonder if that means EOL. I always thought that the board was way underpowered for an expandable chassis like the Arlo. This will give me something to think about, should I or shouldn't I? Not even thinking about an Eddie Board.

Ray

Bill Henning

Rsadeika wrote: »

That sounds like a major project, not having any schematics, I do not think there are any provisions for any other type of recharging methods without of course butchering up the board, which I am not capable of doing. It would be kind of interesting to maneuver a robot two prong recharge wire into a wall socket LOL

Hmm... vision application?

Rsadeika wrote: »

I also noticed that the Eddie Control Board is a final build, I wonder if that means EOL. I always thought that the board was way underpowered for an expandable chassis like the Arlo. This will give me something to think about, should I or shouldn't I? Not even thinking about an Eddie Board.

Ray

I am not familiar with Eddie, however I must admit to having urgers to build BIGGER robots!

Rsadeika

Well I ran into some set backs. I ordered some stuff to test, and just determined that the WiFi with the antenna needs a separate powered USB hub, and I have not seen any that could use the battery pack as a power source. This means that without a functional WiFi setup, it makes using the Pi camera pointless. So, this would be pointless for either setup, Arlo or the Create chasis. The reason for the WiFi with the antenna, provides for a wider operating range, the Raspberry Pi does not have a program that has a switching capability between hotspots. I guess it is back to the drawing board.

Ray

Bill Henning

Hi Ray,

I have about eight different kinds of WiFi sticks... most do not work without a powered hub. There is a page on the Pi wiki that lists WiFi adapters, shows which ones will work without a powered hub.

The following should work:

- USB battery pack with dual output (1A + 2.1A)
- power hub from the 2.1A output
- power Pi from 1A output

I agree re/ WiFi sticks with external antenna for greater range, I have received two different ones that I need to test.

In a few weeks I'll have time to test the above, I'll report my findings once I do.

Bill

Rsadeika wrote: »

Well I ran into some set backs. I ordered some stuff to test, and just determined that the WiFi with the antenna needs a separate powered USB hub, and I have not seen any that could use the battery pack as a power source. This means that without a functional WiFi setup, it makes using the Pi camera pointless. So, this would be pointless for either setup, Arlo or the Create chasis. The reason for the WiFi with the antenna, provides for a wider operating range, the Raspberry Pi does not have a program that has a switching capability between hotspots. I guess it is back to the drawing board.

Ray

Rsadeika

So I made some progress with my RPi WiFi battery setup. The attached images are the RPi with the pi camera taking pictures of its own setup. The RPi camera came with a very short ribbon cable, so I was very limited as to how much I could take in the picture.

The top left item is the "Power Bank", the top right is a 4 port USB hub that is getting some power from the "Power Bank", and the bottom left is just the end of the RPi, which is also drawing power from the "Power Bank". I was logged into the RPi via mstsc on my windows 7 box where I was able to operate the camera to take the pictures.

So far the RPi end of it looks promising for a remote controlled system, but I sure am getting a lot of cables that will somehow have to be dealt with. The next step I guess will have to be hooking the RPi configuration to the Create just to see if I can get that aspect to work. More to come...

Ray

ratronic

Hi Ray I have started to work with computer vision with the Raspberry Pi and my Stingray robot. This just the very begining of my project and I don't have one of Bill's boards but from what I've

seen it would work just fine with the Python code I'm posting, you will need to change the serial tx/rx pins in the Spin program to match were they are connected to Bill's board. This Python program

is set to detect the largest orange blob in the web cam video frames. I tried the Raspberry Camera module but I couldn't get all the noise out. In one of the pictures shows both the masked blob and the real video

with the orange ball with a small blue tracking dot in it. It is sending the current tracking position out the serial port to the Propeller. The forum wouldn't let me upload a .py file so the .txt should be saved as .py.

If you are interested I can let you know how I set it up - I took the easy way.

EDIT: I originally posted the wrong Spin program to match the Python program.

Rsadeika

Looks good ratronic, but it also looks like the Stingray chassis is packed. I am probably going to use the Create chassis as test base, but am seriously considering an Arlo chassis for the real robot.

I am still waiting for the Arlo power board to materialize, I want to see what exactly it is that is on there. One thing that I hope it has is some way or some connection to the power board, so you can monitor the status of the batteries. The other item I mentioned earlier, an automated re-charging system, but I am not holding my breath on that one.

I have been giving The Arlo chassis some thought, I think I might set it up like the Create, have a separate Propeller controller board for the Arlo which will have an Rx/Tx connection that will provide a means for another control system to log in. That way you would send commands to the Arlo board, and the robot responds. The Arlo board would be in control of the battery status, edge of cliff sensors, check for low level objects, ... etc. Thinking out loud on this...

Ray

ratronic

That Stingray is way over packed! I am powering it with a 7.4 volt 5000mah Lipo. My first step is to get the webcam on the rear x,y platform to follow the detected object then in the end I hope to get the

whole Stingray robot to follow around a Scribbler2 (controlled by RC) with the ball on top. I wish I had a bit bigger platform but I am trying to make the best out of what I have. Have fun putting this together!

Rsadeika

Today when I was doing some more testing of the WiFi setup on the RPi, for the heck of it I decided check what port the WiFi was assigned too. In my setup, using the LB-LINK WiFi module, it uses ttyAM0, I believe that it could be a problem with a RoboPi connected, which also uses the ttyAM0 port. Not sure if that would be a problem with other WiFi modules. Just a heads up.

Ray

ratronic

I am not sure how Bill's board firmware talks to the Propeller but on my Pi board ttyAMA0 is the serial port and the way I am using it I had to disable the Pi's serial port console function to use it. Some info on how to do that here.

To find out the usb devices attached I type lsusb in a terminal window.

Bill Henning

Dave,

Looks like a good beginning for computer vision!

I am curious about the noise with the Pi camera module.

Please keep posting updates on how it goes!

Bill

ratronic wrote: »

Hi Ray I have started to work with computer vision with the Raspberry Pi and my Stingray robot. This just the very begining of my project and I don't have one of Bill's boards but from what I've

seen it would work just fine with the Python code I'm posting, you will need to change the serial tx/rx pins in the Spin program to match were they are connected to Bill's board. This Python program

is set to detect the largest orange blob in the web cam video frames. I tried the Raspberry Camera module but I couldn't get all the noise out. In one of the pictures shows both the masked blob and the real video

with the orange ball with a small blue tracking dot in it. It is sending the current tracking position out the serial port to the Propeller. The forum wouldn't let me upload a .py file so the .txt should be saved as .py.

If you are interested I can let you know how I set it up - I took the easy way.

EDIT: I originally posted the wrong Spin program to match the Python program.

Bill Henning

Hi Dave,

RoboPi uses the Pi serial console (/dev/ttyAMA0) + GPIO#17, so the Pi serial console has to be disabled.

heater's modified propeller_load can be used with SimpleIDE / PropGCC / OpenSpin to develop propeller code on the Raspberry Pi.

For "normal" Pi C code, RoboPropLib implements a protocol over /dev/ttyAMA0 that talks to the RoboPi firmware. See my user manual for more info.

Bill

ratronic wrote: »

I am not sure how Bill's board firmware talks to the Propeller but on my Pi board ttyAMA0 is the serial port and the way I am using it I had to disable the Pi's serial port console function to use it. Some info on how to do that here.

To find out the usb devices attached I type lsusb in a terminal window.

ratronic

Thanks Bill.

EDIT: The pictures I posted were using a Python program and opencv2. To get the opencv library for Python use I type sudo apt-get install libopencv-dev python-opencv .

I had slightly noisy video when using the Raspberry Pi camera module but it takes very good still pictures. I am using a Logitech C270 web cam for the above. The serial output consists of a flag of !# and then a byte each showing the x

and y coordinates of the detected object then transmits a word for z showing how large the object is. The video captured is resized to 190 by 140 for faster processing.

Rsadeika

http://www.codeproject.com/Articles/665518/Raspberry-Pi-as-low-cost-HD-surveillance-camera , ratronic you may want to go to this site, he set it up as a surveillance camera, and in the write up he does not make any mention of any "noisy video". I am considering a similar setup on the robot, whichever chassis it turns out be. I want to be able to view the streaming picture, and decide which way I should head the robot. In fact I would also like to be able to do some still shots after the robot finds something interesting to itemize.

Now that I found out that the WiFi uses ttyAMA0, I am considering using the RoboPi as a stand-alone board that would control the Arlo chassis attached sensors. That way I could have a couple of pins for Rx/Tx and they could be connected to the RPi via ttyUSB0. For general information, for this project Spin is good, but C is better, and so all the Propeller related stuff will be in C, and at this point I am thinking that the RPi stuff will be in Python. But things do change, so...

Ray

ratronic

I have spent no time in trying to use the Raspberry Pi camera module because the Logitech webcam was right there and a Python demo program showing object detection using Python wrappers for opencv

using a USB webcam so I did what I always do - take the easy way to do it.