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by amcdonley
Fri Jun 17, 2016 5:47 pm
Forum: Automation, sensing and robotics
Topic: Raspberry Pi camera recording video lag but CPU usage is low
Replies: 4
Views: 2503

Re: Raspberry Pi camera recording video lag but CPU usage is

You mentioned CPU usage is low, but what about the display memory usage? If you allocate more display memory, are the frame rate/lag affected? Perhaps to diagnose - turn off the GUI, record to file, stop the recording, then read the file to the GUI. Also try low frame rates, and try lower capture ar...
by amcdonley
Thu Jun 16, 2016 3:13 pm
Forum: Automation, sensing and robotics
Topic: HC-SR04 causes Raspberry Pi Reboot - Ideas?
Replies: 8
Views: 1486

Re: HC-SR04 causes Raspberry Pi Reboot - Ideas?

Thanks All,

My RugWarrior Pi (B+ powered) robot ran the HC-SR04 sensor for 11 hours yesterday without a surprise reboot, and eventually detected that the batteries had reached knee voltage (6 NiMH cells * 0.9v) and performed an intentional shutdown.

Alan
by amcdonley
Thu Jun 16, 2016 3:06 pm
Forum: Automation, sensing and robotics
Topic: Pi Robot "Memories" - wtmp file
Replies: 2
Views: 1043

Re: Pi Robot "Memories" - wtmp file

Thanks. Good insight and suggestion.
by amcdonley
Wed Jun 15, 2016 9:10 pm
Forum: Automation, sensing and robotics
Topic: Can boost conventer and raspberry pi work together?
Replies: 5
Views: 1181

Re: Can boost conventer and raspberry pi work together?

Fan - This is a very important question, so make sure you understand this answer. The Raspberry Pi has a set of interface pins which have limits and requirements for two very important measures: current and voltage. Everything you want the Pi to talk to will have limits and requirements for: voltage...
by amcdonley
Wed Jun 15, 2016 7:21 pm
Forum: Automation, sensing and robotics
Topic: Pi Robot "Memories" - wtmp file
Replies: 2
Views: 1043

Pi Robot "Memories" - wtmp file

A robot needs, if it can use, some knowledge of history; humans call these "memories". Some say that our memories are what make us individuals. Some robot memories require overt action to store and categorize events, but a Pi based robot has an operating system which quietly stores many ev...
by amcdonley
Wed Jun 15, 2016 2:00 pm
Forum: Automation, sensing and robotics
Topic: Rug Warrior Pi
Replies: 4
Views: 1324

Rug Warrior Pi: Up alone all night

There is a natural anthropomorphism that happens when I spend a lot of time programming a robot. At first it is a just a bunch of hardware with no "life", but eventually I start to feel squeamish about issuing the shutdown command, like I am cheating an artificial intelligence (an AI) out...
by amcdonley
Wed Jun 15, 2016 4:21 am
Forum: Automation, sensing and robotics
Topic: HC-SR04 causes Raspberry Pi Reboot - Ideas?
Replies: 8
Views: 1486

Re: HC-SR04 causes Raspberry Pi Reboot - Ideas?

Fixed!!

I had the Echo going direct to the GPIO pin - ouch, sure glad I didn't fry my Pi.

Changed the wiring and the code - been running for hours now with no reboots.
by amcdonley
Tue Jun 14, 2016 4:54 pm
Forum: Automation, sensing and robotics
Topic: Can boost conventer and raspberry pi work together?
Replies: 5
Views: 1181

Re: Can boost conventer and raspberry pi work together?

12vBatt+ --------------------------------------------------------------- <--(12v to relay and to 12v-5v converter) | | pump<--+12-- relay<-----interface card<-----Pi <--+5--(12v to 5v converter) | |__________|________________ | _______________|<--(5v and signal ground) | | 12vBat - ----------------...
by amcdonley
Tue Jun 14, 2016 3:27 pm
Forum: Automation, sensing and robotics
Topic: HC-SR04 causes Raspberry Pi Reboot - Ideas?
Replies: 8
Views: 1486

Re: HC-SR04 causes Raspberry Pi Reboot - Ideas?

The reason I suspect the HC-SR04 is that the bot will idle for hours with only a WiFi ssh session but when I start my HC-SR04.py test program it runs for a minute or so and then a reboot occurs. The program loops once a second: (PDALib is for Pi Droid Alpha interface card) PDALib.readdistance() Send...
by amcdonley
Tue Jun 14, 2016 2:23 pm
Forum: Automation, sensing and robotics
Topic: HC-SR04 causes Raspberry Pi Reboot - Ideas?
Replies: 8
Views: 1486

HC-SR04 causes Raspberry Pi Reboot - Ideas?

HC-SR04 operation is causing occasional reboots - Ideas?

Detailed write up on my blog at element14: https://goo.gl/QOT9gG
by amcdonley
Fri Jun 10, 2016 11:59 pm
Forum: Graphics, sound and multimedia
Topic: [Q] Mini Mic for voice recognition
Replies: 4
Views: 4472

Re: [Q] Mini Mic for voice recognition

I have just tried that mini mic with pocketsphinx on my Pi 3 - it seems to work just as well as my Kinobo noise cancelling uni-directional mic - 95% or better with small language model (trained on 105 phrases using 136 words). Both were roughly 1m / 3 feet from my mouth, with the opening pointed in ...
by amcdonley
Mon Jun 06, 2016 12:58 am
Forum: Graphics, sound and multimedia
Topic: PocketSphinx on Pi 3 is amazing!
Replies: 0
Views: 6096

PocketSphinx on Pi 3 is amazing!

Raspberry Pi 3 Model B compared with Raspberry Pi B+ 512MB
Using CMU PocketSphinx: https://goo.gl/RrGgCm

and the video: https://vimeo.com/169445418

Pi 3 is going to be a real game changer for my robot.
by amcdonley
Thu May 12, 2016 4:56 pm
Forum: Graphics, sound and multimedia
Topic: Sphinx usage problem
Replies: 2
Views: 711

Re: Sphinx usage problem

Did you find: http://makezine.com/projects/use-raspbe ... e-control/?

Are you making progress?
by amcdonley
Sun Aug 16, 2015 11:22 am
Forum: Automation, sensing and robotics
Topic: Motor and Servo Self Calibration Routines in Python
Replies: 6
Views: 3700

Re: Motor and Servo Self Calibration Routines in Python

... library for the RWP community ... I guess the software was predicated on everyone having the same robot. The common factor was the same robot brain (68HC11 and InteractiveC with multi-processing). It worked for any two-wheeled bot, with variable speed motors, and encoders. The motors could be a...
by amcdonley
Sat Aug 15, 2015 10:35 pm
Forum: Automation, sensing and robotics
Topic: Motor and Servo Self Calibration Routines in Python
Replies: 6
Views: 3700

Re: Motor and Servo Self Calibration Routines in Python

@joan and fellow robot enthusiasts: The majority of personal robots are driven by two DC motors. Even two identical model motors will perform slightly different. In addition the wheels may be slightly different diameter, and may have some wobble which causes the wheelbase to vary slightly. These sli...
by amcdonley
Fri Aug 14, 2015 11:21 pm
Forum: Automation, sensing and robotics
Topic: Motor and Servo Self Calibration Routines in Python
Replies: 6
Views: 3700

Motor and Servo Self Calibration Routines in Python

I am updating my 15 year old robot with a new brain and also adding a tilt/pan mechanism for a Pi camera and an IR range finder. I am interested to have my new robot calibrate its effectors using its sensors. My chassis has 32 stripe wheel encoders which can provide motion detection, max_speed detec...
by amcdonley
Thu Aug 13, 2015 10:59 am
Forum: Automation, sensing and robotics
Topic: PWM for servos, motors, and LEDs plus plus
Replies: 71
Views: 46435

Re: PWM for servos, motors, and LEDs plus plus

Anecdotal Datum for pigpiod: I clocked the processor load of pigpiod default (equivalent to -s 5) on my Pi B+ with top. The CPU% varied from 8.2 to 8.5 with 8.2% the most often seen reading. (This is with no pwm, no callbacks, and no clients.) Joan, (the pigpiod creator), suggested the default sampl...
by amcdonley
Mon Aug 10, 2015 11:54 am
Forum: Automation, sensing and robotics
Topic: PWM for servos, motors, and LEDs plus plus
Replies: 71
Views: 46435

Choosing pigpiod sample rate? Pi PWM vs pigpiod PWM?

I set up pigpiod to start at boot via the crontab entry: @reboot /usr/local/bin/pigpiod This runs the pigpiod at the default sample rate of 5 uSeconds. With no events, no callbacks, and no clients, pigpiod loads my Raspberry Pi B+ at roughly 9% CPU. The pigpiod docs show possible sample rate options...
by amcdonley
Sun Jul 26, 2015 4:04 pm
Forum: Automation, sensing and robotics
Topic: Rug Warrior Pi
Replies: 4
Views: 1324

Rug Warrior Pi

Hello robo heads, I've finally decided to get serious about updating the brain of my Rug Warrior Pro robot. There used to be hundreds of Rug Warrior and Rug Warrior Pro (RWP) robots scurrying about for university research, hobbyists, and education. My RWP robot is 15 years old now, and really needs ...
by amcdonley
Sun Feb 01, 2015 4:28 am
Forum: Troubleshooting
Topic: Alsa conf default input rate
Replies: 1
Views: 2418

Re: Alsa conf default input rate

So far the only thing that works is putting an alias in my .bash_aliases: .bash_aliases: alias arecord48='arecord -F s16_LE -r 48000' so that: arecord48 test.wav gets me 48k 16bit Mono recordings. The whole sound system on my Pi B+ just seems a mess: 1) There is a 20-30 second delay the first time I...
by amcdonley
Thu Jan 29, 2015 5:08 am
Forum: Troubleshooting
Topic: Alsa conf default input rate
Replies: 1
Views: 2418

Alsa conf default input rate

Audio Configuration: Output: RaspberryPi B+ headphone jack "hw:0,0" Input: USB microphone "hw:1,0" I have figured out the "split config" /etc/asound.conf to make the onboard bcm2835 chip be the default pcm playback device, and for the USB mic to be the default capture d...
by amcdonley
Tue Jan 27, 2015 9:33 pm
Forum: Beginners
Topic: Omxplayer
Replies: 3
Views: 1071

Re: Omxplayer

Perhaps you want to use a semi-colon instead of the ampersand? With a semi-colon the shell waits until the omxplayer completes before executing the "exit" command (which takes the shell and all child processes out of execution). BTW, The user running omxplayer needs to be in the video grou...

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