Roomba SE Recieving Serial Data

[tkj]

Hi.
I've just got my RS232 to Roomba board soldered today and got it working, nearly
I can send data to the roomba, control it, but i can't recieve any data.
I'm using a MAX232 and a 7805 to convert the RS232 serial data to TTL level, and i know it is working, as i can make a loop and then recieve the same data as i send!

If i initialize the Roomba serial communication by sending 128 and 130 using Baud 57600 bps, if i then plug in the power adapter, the Power LED switch to red/orange, but i don't recieve any data.
Also if i reset the roomba by sending 7, i don't recieve anything either!
I've also tried taking out the battery and plug it in again - nothing...

What is the problem?


Best Regards
Thomas Jespersen

[vic7767]

Remove your battery, press Pwr button for 10 seconds. Replace the battery, set up your comm environment, plug the power supply directly to the Roomba power jack and monitor the ASCII output from the SCI port. The charging data is sent by the Roomba once per second. If you don't receive anything then you have an issue somewhere between your PC receive and the Roomba Tx leads.

mfortuna also mentioned that if you are using the schematic from the Hacking Roomba book there is a ground missing in the drawing.

[tkj]

Nope, nothing!
This is the schematic of the MAX232 board - http://www.mikroe.com/pdf/max232_board_ ... c_v100.pdf
And i don't know if the problem could be that the RX line isn't pulled up using a resistor?
Should i try to pull the RX line up using a resistor, or would that fry the Roomba?

Just to inform you, on the schematic the RX is Output (to roomba) and the TX is Input (from roomba)!

[mfortuna]

Make sure pin 5 of your db9 is grounded. It shows a ground in the schematics but maybe you have an open?

[vic7767]

Try this transmit test. With the power supply plugged into the Roomba and the charging status LED either blinking or steady, send the reset command 7. The charging status indicator should go off for a few seconds then come back on and indicate a low battery (red LED).

[tkj]

I know it's grounded as i'm using a bought MAX232 module from MikroElektronika, which måde this schematic over their board.
And i know transmitting is working perfectly, both when i use Roomba Status, but also if I make my own serial program.

[tkj]

So, so make a summary:

• I can't read/get the data from the roomba
• NEW - I can't use Roomba Status to set the roomba into Seeking after Charger mode
• NEW - I can't/don't know how to start/use RoombaComm on windows

[mfortuna]

Check the connections you made to the Roomba serial port. Maybe you have a wire in the wrong place.

[tkj]

Check the connections you made to the Roomba serial port. Maybe you have a wire in the wrong place.

Nope, everything is fine there.
I've ohmed the cable, checked the connections on the breadboard - and everything is fine!

[mfortuna]

So if you loop TTL TX to RX on your module does it work? I think you did this. Unplug the RX line from the roomba and tie the TX and RX together. You should get characters looped back on the PC. If this works it says the roomba is not returning data. You should not need a pullup on RX.

[tkj]

So if you loop TTL TX to RX on your module does it work? I think you did this. Unplug the RX line from the roomba and tie the TX and RX together. You should get characters looped back on the PC. If this works it says the roomba is not returning data. You should not need a pullup on RX.

Yes i've tried that, and yes i reiceve the same data as i send!

[mfortuna]

With the roomba off and charging you should see battery information once every second. Try downloading realterm, that is the program I have great luck with.

Now if the roomba is not responding to SCI commands it may be the firmware is too old and would require a OSMO to add SCI capability.

[tkj]

With the roomba off and charging you should see battery information once every second. Try downloading realterm, that is the program I have great luck with.

Now if the roomba is not responding to SCI commands it may be the firmware is too old and would require a OSMO to add SCI capability.

The roomba is responding to serial commands, and i can control it using the Roomba Status or my own Visual Basic software.
But the only thing I can't, is to recieve data from the roomba!
As i don't even get the power information every second

[tkj]

Now I successfully made a bluetooth module for the Roomba, but that isn't working with the recieving part either!
I can send commands to control the Roomba, and that works perfectly, but I still can't recieve data!

[mfortuna]

It sure sounds like the roombas RX line is not functioning maybe due to a blown IC or a bad connection between the controller and serial port.

[tkj]

It sure sounds like the roombas RX line is not functioning maybe due to a blown IC or a bad connection between the controller and serial port.

So what should i do? Any suggestions?

[vic7767]

You might consider testing your transmit / receive hardware with another Roomba if you have access to one. You can also consider obtaining the Create IRobot com cable for $19.95 on the IRobot web site.

[tkj]

You might consider testing your transmit / receive hardware with another Roomba if you have access to one. You can also consider obtaining the Create IRobot com cable for $19.95 on the IRobot web site.

I only have this Roomba, and i can't buy the cable as i don't live in the US, and iRobot doesn't ship the Create out of North America. Isn't that correct?

[vic7767]

You might consider checking with Chris, on his web site are different hardware options you could purchase. He does ship internationally.

http://www.protechrobotics.com/roomba_dev_tools.php

[tkj]

I'm very confused now...
Because if i take my Oscilloscope, set it to Trigger and then measure between the two pins on the picture, nothing is going on. So it means that nothing is being transmitted!
I've tried the to plug the power in, but nothing happends afterwards either.


The picture is seen from above, as if you look at the connector on the Roomba