Roomba Python test script not working

[huitlacoche]

Hi,

I'm trying to get my roomba Discovery to work via a python script but nothing seems to make it respond.
I know that my bot has the updated firmware and I've gotten it to function over an arduino but I'd rather make things leaner and go the python route.

Here's the code:

Code: Select all

import serial

ser = serial.Serial('COM4', 57600) # open serial port 4
print( '%s is in use.' %(ser.portstr) ) # check to see if port is open

#start Roomba commands


ser.write(b'/x80') # 128: start command
ser.write(b'/x82') # 130: control command
ser.write(b'/x87') # 135: clean command


##ser.write( bytes('/x80', encoding='ascii') ) # 128: start command
##ser.write( bytes('/x82', encoding='ascii') ) # 130: control command
##ser.write( bytes('/x87', encoding='ascii') ) # 135: clean command


ser.close() # close port


I'm using Python 3.3, as well. I did some investigating to see if the syntax has changed...that's why there is two different versions of the same command.
Has anyone else run into the problem and found a way around it?
I know that my usb to serial device is working as I can get things to function in Roomba Status.

Thanks!
-- Mark

[huitlacoche]

So I realize now that it *is* waking up. Device detect seems to be working but I still can't send commands.
I checked to see if perhaps my usb to serial device wasn't working with an Arduino. I created a short python script with a ser.read() and it returned byte info...I'm still thinking my syntax is incorrect between python and roomba.

[vic7767]

Is the power on prior to sending commands ?

[huitlacoche]

No, power is off.
So a bit of an update after playing around, I modified the code a bit:

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import serial
import time

ser = serial.Serial('COM4', 57600)

ser.setRTS(0)
time.sleep(0.1)
ser.setRTS(1)
time.sleep(0.75)

ser.write(b"\x80") # 128: start command
ser.write(b"\x84") # 130: control command
ser.write(b"\x87") # 135: clean command

ser.close()

I had originally tried setting the baud to 19200 and using just 'ser.setRTS(0)'
To my delight, it started to vacuum...once.
I'm not sure why it woke up that one time and not again but I pasted in the rest of the wake up sequence and it started working consistently. I had to pull the battery to get it working at 57600 as well.
I didn't think I had changed the baud rate with just a simple ser.setRTS(0). I figured i had to pulse the device detect as it says in the SCI manual. In short, it seems to consistently vacuum now. I need to figure out if this is something that will work for other commands.

I'm still pretty new to this so I'm just throwing together strings of code in a fashion that I think might work...

Code: Select all

ser.setRTS(0)
time.sleep(0.1)
ser.setRTS(1)
time.sleep(0.75)


All this does is wake up the roomba, correct? I've seen it in snippets of code and I've seen others without. I apparently need this in my code to make my roomba do anything. Is there a reason other people get theirs to work without this?

Thanks!
-- Mark

[huitlacoche]

Oh, and another problem is the fact that i had a forward slash instead of a backslash in my byte code.
Luckily I caught that error before I ran in too many circles.

[mfortuna]

The roomba can be powered on manually before SCI commands are sent. It doesn't need to be woken up if it is powered on.