Roomba Status communication problems

[huitlacoche]

Hi,

So I'm getting some ambiguous responses from my Roomba in Roomba Status.
I made a simple cable to connect the Roomba to a usb-to-serial breakout board I have. I only wired it with ground, Tx, Rx and device detect.
The port is configured correctly and the usb to serial board seems to be responding but the only communication I can do between Roomba Status and my Roomba is turn it on.
I have a Roomba Discovery 4220 and I verified that the firmware is version 2.1. Obviously the thing is responding but I'm wondering where I've come up short.

Thanks!
-- Mark

[vic7767]

Try monitoring the SCI while the charger is directly connected to the Roomba. There is a charging status report that is output once per second as long as the power supply is directly connected.

[huitlacoche]

Is there another program I can use to monitor the SCI? Sorry, I'm a bit new to all of this.

Also, I'm fairly certain that this says my bot was manufactured after Oct 2005 and therefore has the firmware with
the SCI on it. Can anyone confirm this for me so I can eliminate the possibility that I have to upload the hack?

Thanks again!

[vic7767]

Your Roomba date is September 18, 2006 so no issue there. You can use other terminal programs like TeraTerm or RealTerm or HyperTerm to test your setup.

[huitlacoche]

So I've had a little more time to spend with this and I tried out Realterm as well. Still no luck.
Roomba status will allow me to turn on my roomba but it just stays in passive mode and 'connecting...' as the sample count goes on and on and on. Pressing movement enables full-mode but that still doesn't do anything. Althewhile my usb-to-serial's transmit light is blinking.

Again, everything on the port side is configured correctly, my Usb to Serial's port is 4, baud rate is 57600, parity set to none, data bits to 8, stop bits to 1 and hardware flow control to none.

Now if I try out Realterm, it sees my port but here's where I get a little lost. If i start it up with the usb to serial board plugged in and connected to my roomba, it sees the port but the status does nothing except blink a yellow TXD if i type in a string and hit send numbers (I'm using '128 132'). This also causes my transmit led on the usb to serial to blink once. Now if i unplug the usb to serial port from my computer and plug it back in again, Ring, DSR and CTS will begin to blink. I transmit the same string again and it does nothing. Realterm claims it transmits but no light up on the Usb to serial and no action out of the Roomba.
To rule out whether its the usb to serial connector or the roomba, I'm going to run the TurnBump sketch in arduino and see if that actually does anything.
If anyone has any thoughts of something else I can try (or a step I've overlooked), I'd appreciate it!

Thanks!
-- Mark

[mfortuna]

As vic7767 mentioned start by running a terminal emulator with your cable connected to the roomba and the roomba either docked or with the power supply plugged in. You should see once a second charge information. If you don't, double check your cable. Make sure TX from the breakout board is connected to RX on the roomba and vice-versa. The fact that roomba status turns on the robot probably indicates the DD signal is working.

[huitlacoche]

I think I tried running realterm with the roomba docked to no avail.
Let me try and swap the tx/rx pins. I might have wired them so they go tx - tx and rx - rx.
Yeah, as far as I know the device detect pin works so that's a plus!
One thing I didn't mention was that I took the brush assemble off from underneath...just the brushes. I didn't think that would cause any havok but then I'm not certain.

Thanks,
-- Mark

[vic7767]

Removing the cleaning brushes from the brush deck will not cause any issues with the Roomba or its SCI function. Once you can receive the charging reports on the Realterm screen you should be all set to communicate with your Roomba.

[huitlacoche]

Just to verify:
http://osepp.com/products/breakout-boar ... out-board/
this is the ftdi breakout I have. I'm assuming it should work just as well as any ftdi cable. I couldn't verify if it's active high TTL logic (rather I'm not sure what would give that away as I can't find too much information on this board).

Thanks

[vic7767]

Here's what I use: http://www.ebay.com/itm/CP2102-USB-2-0- ... 1e6d5ebbc3

Also before you try your next comm session try removing the battery for a couple of seconds and then install it. This may restore the SCI port. Sometimes the port gets locked up.

[mfortuna]

It is active high.

[huitlacoche]

Reset and a Tx/Rx pin swap was all it took. It's Alive!!

Thanks a ton guys!
-- Mark

[mfortuna]

No problem. Enjoy hacking with your roomba!

[huitlacoche]

Hello again,

So some things that I've noticed. Roomba Status seems to work more or less all of the time yet realterm doesn't seem to function most of the time. I plug in and set my correct port but half the time it doesn't bother to give the roomba's status in the terminal window and it doesn't look like I can send commands like this:
http://www.robotappstore.com/Knowledge- ... ba/18.html

So I'm not sure if I still have a problem or if this is a realterm thing. I took the battery out again and pressed the power buttonn for 5 seconds and reinstalled the battery and only then did realterm see anything but I was still unable to send commands. Would I not be getting a series of blinking lights in the status window if it were working correctly?
I'm rather baffled by this. It seems to work and then it doesn't. heh

Thanks!
-- Mark

[huitlacoche]

Also it's suddenly been acting weird in Roomba Status. The battery info will at times return 0 mAh and 'max' and 'clean' will turn on on their own while I'm doing nothing more than driving the thing with the directional keys. Could this be a battery issue?

-- Mark

[mfortuna]

I have seen roomba status return bad info lots of time but I have not seen it suddenly make the robot start cleaning. It sounds like the get status command is sometimes being miss-interpeted. You could try lowering the BAUD rate by sending the appropriate command. I recall realterm working for me but I rarely use it.

[huitlacoche]

What's interesting to me is that Roomba Status works most of the time yet Realterm acts as if it's never connected. The two should be working with the same data. At any rate I was only using realterm to see if I had an established link. I think Roomba Status proved that but it's still bothersome that it seems so erratic.

[mfortuna]

I will try out realterm on my security bot tonight and see if I can learn anything.