Radio options beyond RooTooth

cadcoke4 · Post by **cadcoke4** » October 9th, 2006, 9:30 pm

While the RooTooth is a good product. I really think that I would prefer the range available with the 802.11g standard. I know there has been talk about the possibility of iRobot adding this as a feature, but of course we have no definite information.

I am looking at what the current options are, especially ones that don't require a custom circuit board.

I was looking at Tiger Direct, and saw this 802.11g wireless USB print server. $40 (after rebates) http://www.tigerdirect.com/applications ... &CatId=371

I wonder if I can plug this into a RooStick, and give the Roomba 802.11g capability?

There are also other similar devices with multiple USB ports (perhaps they can allow a USB camera?) and ones with parallel ports (data O/I ports?). I know the parallel port might theoretically be able to simulate a serial port using some of its pins, but that might get very messy with the programming.

Looking at some of the user reviews of the wireless print servers, several commented about the product they purchased not working with multi-function printers. I.e. no bi-directional data.

While the hardware specs on these 802.11g devices seem to imply they will work, I have my doubts.

THX-1138 · Post by **THX-1138** » October 10th, 2006, 11:50 am

Definitely, iRobot is working on something similar. The issue is not if it is possible but instead one should ask how could it be done without sacrificing size and battery life as they are currently on the Discovery series. Do a search within this forum and you will find similar projects done by forum members already.

cadcoke4 · Post by **cadcoke4** » October 10th, 2006, 12:46 pm

THX said;
>Definitely, iRobot is working on something similar.

Do you have any sense of how immenent this would be? I would hate to buy something this month to start hacking, only to find they've released something next month that would have made my work much easier.

cadcoke4 · Post by **cadcoke4** » November 2nd, 2006, 12:06 am

I just corresponded with the roombadevtools company that sells the Rootooth. I was inquiring about the possibility of any user i/o with the Rootooth.

I was surprised to learn that there is an I/O pin, though it is not supported by the company. They said the user manual would provide some data on that.

But, I am having difficulty understanding it. It seems to be the same pin that is used by the Roomba SCI to wake a sleeping Roomba. Thus the pin really isn't available, unless you cut that wire and give up that feature.

I wonder if this available pin might be usable as a means of serial communication with a Basic Stamp ? Perhaps by tapping into one of the indicator LED's on the Roomba we could get a method for data flow control?

cadcoke4 · Post by **cadcoke4** » November 3rd, 2006, 9:21 am

I just came across the Toothpick on Parallax's site, and after I found some real information about it, I was impressed by its abilities.

Here is Parallax's site (with minimal information)
http://www.parallax.com/detail.asp?product_id=30076

Here is the link to the manufacturer's site with complete information in a PDF
http://www.flexipanel.com/BluetoothModules.htm

While the device is being marketed as working with a separate Basic Stamp, I wonder if this device can be used as-is, without the Basic Stamp. The device seems to have pinouts for several Analog/Digital inputs, and serial comminications ability. If I want to do my processing remotely, then I can just use this device by itself... at least that is what I am thinking may be possible.

I am also reconsidering my love of the 802.11 WiFi. As I learn more, I realize it is not designed to work as close to real-time as the Bluetooth standard does. Also, apparently Bluetooth can work up to 330 ft (open space). Of course, the big question is if it will work within range of my house.

cadcoke4 · Post by **cadcoke4** » November 3rd, 2006, 2:51 pm

I have a reply to some questions about the Toothpick I posted to a Parallax forum.

I now understand that the Toothpick is a complete microprocessor and Bluetooth device in one. The Parallax site sells a special "Basic Stamp" edition where the Toothpick can only be used in conjunction with the Stamp. Note that it will work with any Stamp, except for the Stamp 1 (unfortunately that is the one I have).

The firmware on the Toothpick can be changed pretty easily, and several versions which reconfigure the Toothpick can be chosen at purchase time, or field changed. The Toothpick itself can be programmed in C and will certainly serve as a controler for a robot all by itself.

Joe Dunfee

cadcoke4 · Post by **cadcoke4** » November 9th, 2006, 1:04 am

I recently re-discovered the sparkfun.com site. I think the last time I was there, they didn't have all of the current site up yet.

They have some roomba specific devices; serial, usb and bluetooth connections. But the bluetooth Roomba dongle doesn't allow us to to add our own sensors, etc.

But, they also have some low-cost bluetooth chips in DIP packages that look like they can easily be interefaced with the Basic Stamp and other microchips. If I didn't already have the Parallax product already shipped, I would have gone with the Sparkfun product. Here is a link;

http://www.sparkfun.com/commerce/catego ... ath=16_115

roadknightlabs · Post by **roadknightlabs** » November 9th, 2006, 3:55 pm

I still think there's room/need for an 802.11-based system due to the inherent low-power draw/range of Bluetooth. Our place is an apartment in an remodeled old-construction building in San Francisco. The walls and pipes just soak up RF like you wouldn't believe.(We've got 3 APs in the house just to provide full coverage everywhere).

I know that I can't leave my Treo 650 in the bedroom(front, facing the street) and expect to get calls on my bluetooth headset when I'm in the kitchen(way in the back) or even the studio area(2 rooms down the from bedroom). So 802.11 it's gotta be, at least for me.

Another thing to watch out for is the Roomba itself. A fellow hacker pointed out to me the other day that he noticed that the Roomba itself uses 2.4Ghz in the WiFi channel 2-6 space for the IR Beacons.

I can see Bluetooth working better in places of more modern construction where the walls and other structures are more transparent to RF.
It will be okay for driving your Roomba around with your phone as long as you're within LOS of it. As a general solution for networking your Roomba, I think it's going to come up short.

cadcoke4 · Post by **cadcoke4** » November 9th, 2006, 8:15 pm

I learned last week that there are different classes of power for Bluetooth. Class 1 is the most powerful and is rated for an open range of 100 meters (over 300 feet), this is the same rating as a standard WiFi router. But, I don't know how their ranges compare inside.

To get that range, both ends of the bluetooth connection must be at that power. Also, your lack of range may be because most headsets use the class 2 (lower power), with its better battery life.

WiFi turns out to be more complicated because it is designed to function more like an internet connection, whereas the bluetooth standard is really designed as a cable replacement. It really is easier to use Bluetooth with its lower power consumption, cheaper price, and with comparable range if you stick to Class I (not to be confused with the various versions of the standard, because the current version is 2)

One benfit of WiFi is that there are low cost range extenders out there, which might make whole-house coverage easier.

gssincla · Post by **gssincla** » November 10th, 2006, 6:09 am

roadknightlabs wrote:A fellow hacker pointed out to me the other day that he noticed that the Roomba itself uses 2.4Ghz in the WiFi channel 2-6 space for the IR Beacons.

Really? I've taken apart of a few of my IR beacons and never noticed any RF components within the device. What exactly did your friend find that was producing interference on that frequency?

Attorney · Post by **Attorney** » November 27th, 2006, 11:05 pm

cadcoke3 wrote:
I wonder if I can plug this into a RooStick, and give the Roomba 802.11g capability?

There are also other similar devices with multiple USB ports (perhaps they can allow a USB camera?) and ones with parallel ports (data O/I ports?). I know the parallel port might theoretically be able to simulate a serial port using some of its pins, but that might get very messy with the programming.

Looking at some of the user reviews of the wireless print servers, several commented about the product they purchased not working with multi-function printers. I.e. no bi-directional data.

While the hardware specs on these 802.11g devices seem to imply they will work, I have my doubts.

Hey, that was my idea. It would have to have bi-directional though. If its printer port specs you may not even need the 232 conversion chip.

vic7767 · Post by **vic7767** » November 28th, 2006, 12:37 am

But I thought the TTL function of the Roomba Open Interface had to be converted to RS232 levels to connect to RxTx external devices.

cadcoke4 · Post by **cadcoke4** » November 28th, 2006, 8:15 am

The Roomba is expecting TTL (5v) level signal, NOT RS232.

Joe Dunfee

vic7767 · Post by **vic7767** » November 28th, 2006, 6:31 pm

That's what I thought I said. The external devices I mentioned are like the roo devices and bluetooth devices. I understand that the Roomba Open Interface is TTL logic. But most of the GUI interfaces utilize RS232 protocols, DB9 port, USB with communication software, Hyperterm, Procomm, SCItester, Roombacomm, etc

cadcoke4 · Post by **cadcoke4** » November 28th, 2006, 10:53 pm

Vic, perhaps I still don't understand your question, but here is another try.

First, I think the RS232 standard specifies its voltage as +12 and -12 for its signaling. The "level shifting" that goes on when you want to connect a 5 volt device to RS232 is just performing a voltage conversion. However, the actual content transfered over the wires is not in any way modified.

This brings up the next phrase, which is "TTL Level RS232"... this is not true RS232, but a 5 volt version of it. The actual encoding of the data is the same, though.

I am currently working to add a computer on a chip (a Basic Stamp) to the Roomba. It will interface to the Roomba using 5 volt logic.

Joe Dunfee

gssincla · Post by **gssincla** » November 29th, 2006, 6:22 pm

cadcoke3 wrote: First, I think the RS232 standard specifies its voltage as +12 and -12 for its signaling. The "level shifting" that goes on when you want to connect a 5 volt device to RS232 is just performing a voltage conversion. However, the actual content transfered over the wires is not in any way modified.

This brings up the next phrase, which is "TTL Level RS232"... this is not true RS232, but a 5 volt version of it. The actual encoding of the data is the same, though.

What Vic was saying was that you can't do native RS232 with the roomba unless you have a TTL level converter. the original poster was mentioning using the LPT as an interface to the roomba. Vic was questioning how that would work because you need the 0-5v levels not the standard RS232. I'm sure Vic knows how the RS232->TTL works... the man's got an army of roombas!!!

greg.

roadknightlabs · Post by **roadknightlabs** » November 29th, 2006, 9:25 pm

gssincla wrote:
roadknightlabs wrote:A fellow hacker pointed out to me the other day that he noticed that the Roomba itself uses 2.4Ghz in the WiFi channel 2-6 space for the IR Beacons.
Really? I've taken apart of a few of my IR beacons and never noticed any RF components within the device. What exactly did your friend find that was producing interference on that frequency?

Never mind. I thought about this and realized he was confused. Same frequency yes, but we're talking radio vs. optical here. D'oh!
My bad.

gssincla · Post by **gssincla** » November 30th, 2006, 12:44 am

roadknightlabs wrote: Never mind. I thought about this and realized he was confused. Same frequency yes, but we're talking radio vs. optical here. D'oh!
My bad.

lol, no problem. i was curious how your friend found that... i was about to start tearing apart more of my roomba accessories

stevepyle · Post by **stevepyle** » December 1st, 2006, 10:43 am

Hi All,
Newbie here, but looking forward to hacking my 2 roomba disco's
So I'd be interested in you thoughts...

Bought 2 of these USB devices (one for the PC and one for Roomba) http://cgi.ebay.co.uk/USB-Bluetooth-Ada ... dZViewItem

Planning on interfacing it to roomba via one of these http://www.ftdichip.com/Products/Evalua ... 32R-WE.htm

Total cost around ?25, could it work?

vic7767 · Post by **vic7767** » December 1st, 2006, 9:10 pm

Hi Stevepyle

If you want to go bluetooth wireless, the usb stuff you got for the pc side may be ok but for the roomba go to this site and read about the hardware available for the roomba sci port.

http://www.roombadevtools.com/productca ... dproduct=1

Robot Reviews

Radio options beyond RooTooth

Radio options beyond RooTooth

Re: Radio options beyond RooTooth

Blue tooth USB -> TTL interface