Month: February 2021

Much improved Pi Assistant message reader.

The most important improvement is that this program now works… 😎 

I just leave it running on the Pi Assistant, along with the Google provided assistant_library_with_button_demo.py program that I like to use, when I want to ask the Google Assistant something…

#!/usr/bin/python3
#
# Program to run on PiAssistant, to watch for newly arrived text files in
# /home/pi/Messages that it should speak, and delete them once it has.
import os
import paramiko
import time

path = “/home/pi/Messages/”

while True:
    with os.scandir(path) as entries:
        for entry in entries:
            f = open(entry, “r”)
            content = f.read()
            f.close()
            command = “python ~/AIY-projects-python/src/aiy/voice/tts.py “” +
                      content + “” –lang en-GB –volume 10 –pitch 60 –speed 90″
            os.system(command)
            os.remove(path+entry.name)      
            # Now wait for tts.py to finish
            command = “ps -ef | grep -v grep | grep “voice.tts” | wc -l”
            while True:
                ssh_stdin, ssh_stdout, ssh_stderr = ssh.exec_command(command)
                answer = str(ssh_stdout.read())
                if answer[2] == “0”:
                break           
            time.sleep(0.5)
    time.sleep(0.5)

And here is a program to run on a cluster of Raspberry Pi computers, as say_who.py, which will each send a message to the Pi Assistant, from each core of the processor. The assistant will read them out, separately. It does seem still to lose some messages, and if I work out why, I will let you know! I have been searching for simple example programs for Raspberry Pi clusters on the internet for ages, and have not found very many. Here’s my little gift…

#!/usr/bin/python3
from mpi4py import MPI
import os
import time
import subprocess as sp
# Attach to the cluster and find out who I am and what my rank is
comm = MPI.COMM_WORLD
my_rank = comm.Get_rank()
cluster_size = comm.Get_size()
my_host = os.popen(‘cat /etc/hostname’).read().strip()
    
# Make something for the assistant to say
speech = “Host is  {} “.format(my_host)
speech = speech + “Rank {} “.format(my_rank)
# Make a unique filename and path
message = “/home/pi/” + my_host + str(my_rank)
          + time.strftime(“%H%M%S”) + “.txt”
# Put the speech in the file
fp = open(message,”x”)
fp.write(speech)
fp.close()
# Put a copy of the file on PiAssistant
cmd = “scp ” + message + ” pi@PiAssistant:/home/pi/Messages/”
sp.call(cmd,shell=True)
os.remove(message)
You would load that program on each of the Pi machines in your cluster, and then set it running using the command

mpiexec -n 16 -hostfile myhostfile python3 say_who.py

I’m assuming you have four Pi 3 machines in the cluster, hence the -n 16 parameter. 

#RaspberryPi #Cluster #Python

A new program for Google Voice AIY

My earlier post, about a function that could send things to the Google AIY Raspberry Pi Assistant, and supposedly prevent more than one message being spoken at a time, was errmmm, wrong. That’s a technical term, that we programmers use.

I wrote a test program for my Pi cluster, whereby each of the sixteen cores would announce its hostname and rank. It’s not all that often you get the opportunity to use the word cacophony, but…

Basically, several processes could all think the Assistant was not busy, and they all sent messages in the time it took for the first message to start being spoken.

I spent a while looking at how to program mutual exclusivity for a resource, and was impressed by how complex such an apparently simple thing can get.

I decided that what was needed was a simple program, running on the Assistant, that would watch a directory, notice when a file to be spoken arrived, and speak the text in that file. Python makes it easy to deal with more than one file in the directory. Here’s what I wrote…

#!/usr/bin/python3

#
# Program to run on PiAssistant, to watch for newly arrived text files in
# /home/pi/Messages that it should speak, and delete them once it has.
import os
import time
path = “/home/pi/Messages/”
while True:
    with os.scandir(path) as entries:
        for entry in entries:
            f = open(entry, “r”)
            content = f.read()
            f.close()
            command = “python ~/AIY-projects-python/src/aiy/voice/tts.py “” +
                      content + “” –lang en-GB –volume 10 –pitch 60 –speed 90″
            os.system(command)
            time.sleep(0.5)
            os.remove(path+entry.name)
    time.sleep(0.5)

When it spots one of more files in the Messages directory, it reads the text, and sends it out to be spoken. It can supposedly only do one file at a time, but… Still the cacophony!    

#RaspberryPi #GoogleAIY #Python            

How not to make a Twitter poll.

A Question of Saffron

Something or other reminded me recently that I can’t seem to detect the smell or taste of saffron. A lot of people love it, and write passionately about it. They’ve smelled it being brought to them even before the waiter came through the kitchen door. They say they’ve had it explode in their mouth. And I have missed out… 

I wondered whether it was just me, or a fairly common thing, to be unable to smell and taste saffron, so I made a Twitter poll.














It was worded very poorly. To be fair to myself, at the time, I didn’t think about it at all carefully. The result was that it didn’t work the way I had expected.

A lot of people thought this was a question about whether saffron is wonderful, whether it is over-priced, or any of several possible interpretations. What I should have actually asked was “Can you smell and taste saffron”. Like this…












Of course, this isn’t good enough, either, as it discriminates against people who want to say that they can’t afford saffron, or have never heard of it. But the worst thing is, all we can tell from the result of the original poll is that about half the people who saw the poll, and answered it,

  • like the smell of saffron

and about half of them 

  • think it is too expensive.
which actually tells us nothing at all about how many people can detect the taste and smell of saffron, and how many cannot.

Conclusion

Polls. We see lots of them quoted, and they are mostly about politics, and are supposed to let us know how people think about things that matter rather a lot more than whether one can detect saffron.

And a lot of those polls are even less well designed than mine. Some are even designed to make people draw the wrong conclusion, and it’s not easy to tell which ones those are, is it?







Using Google AIY voice.

Using Google AIY voice, part 94.

I wrote a useful function, so that any of my Raspberry Pi machines could send a string to the Google Assistant as a message to be spoken aloud, and it worked very well. Here it is…
# A function to send a string to PiAssistant for output as speech
import paramiko

ssh = paramiko.SSHClient()
ssh.load_host_keys(filename=’/home/pi/.ssh/known_hosts’)
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

server, username, password = (‘PiAssistant’, ‘pi’, ‘your_password-goes_here’)
def say_this_with_assistant(say):
    ssh.connect(server, username=username, password=password)
    command = “python ~/AIY-projects-python/src/aiy/voice/tts.py “” + say + “” –lang en-GB –volume 10 –pitch 60″
    ssh.exec_command(command)
    ssh.close()
    return 

print(“Starting…n”)
say_this_with_assistant(“Normal service will be resumed as soon as possible. “)
print(“Finished.n”)

The snag occurs when two, or more, machines want to say something at the same time. The PiAssistant calmly multitasks, and says the strings at the same time, which sounds interesting, but tends to be incomprehensible. I hoped that voice/tts.py would have some way of letting other programs know whether it was busy, but it doesn’t. However, the low level Linux ps command can tell when voice/tts.py is running, so I added a check for that as a Paramiko command, like this…

# A function to send a string to PiAssistant for output as speech when it’s free
import paramiko
import time
ssh = paramiko.SSHClient()
ssh.load_host_keys(filename=’/home/pi/.ssh/known_hosts’)
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
def say_when_free(say):
    server, username, password = (‘PiAssistant’, ‘pi’, ‘your_password-goes_here‘)
    ssh.connect(server, username=username, password=password)    
    command = “ps -ef | grep -v grep | grep “voice.tts” | wc -l”
    while True:
        ssh_stdin, ssh_stdout, ssh_stderr = ssh.exec_command(command)
        answer = str(ssh_stdout.read())
        if answer[2] == “0”:
            break
        
    command = “python ~/AIY-projects-python/src/aiy/voice/tts.py “” + say + “” –lang en-GB –volume 10 –pitch 60″
    ssh.exec_command(command)
    ssh.close()
    return 
print(“Starting…n”)
say_when_free(“I waited until I was allowed to say this. “)
print(“Finished.n”)
I’m not going to claim  any of this as properly written Python, the best way to do what is required, or even particularly original, but it does currently seem to be the only description of how to do this that’s on the internet.