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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: 3241

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: 41979

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: 41979

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: 1
Views: 846

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: 2110

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: 2110

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 device (working file at end of ...
by amcdonley
Tue Jan 27, 2015 9:33 pm
Forum: Beginners
Topic: Omxplayer
Replies: 3
Views: 938

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 group. Old but...

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