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by Idahowalker
Mon Oct 22, 2018 12:36 pm
Forum: Automation, sensing and robotics
Topic: Measuring UBEC output voltage
Replies: 2
Views: 52

Re: Measuring UBEC output voltage

I received today this UBEC https://www.banggood.com/Hobbywing-3A-UBEC-5V-6V-Switch-Mode-BEC-For-RC-Models-p-915037.html?utm_design=41&utm_source=emarsys&utm_medium=Shipoutinform171129&utm_campaign=trigger-emarsys&utm_content=Winna&sc_src=email_2671705&sc_eh=130273cb35096df51&sc_llid=7033010&sc_lid=...
by Idahowalker
Sun Oct 21, 2018 2:30 am
Forum: Troubleshooting
Topic: Raspberry pi heat problem
Replies: 2
Views: 61

Re: Raspberry pi heat problem

Watching the PefMon, does the program start up and ramp up to a high CPU percent rate of use or does it take 30+ minutes or several hours to ramp up the cpu percent of use. Say, when cpu use gets to around 50%, stop the program, does the % of cpu use drop quickly or does it continue at 20% or more? ...
by Idahowalker
Thu Oct 18, 2018 12:26 pm
Forum: Other projects
Topic: Fan with no heatsink
Replies: 8
Views: 149

Re: Fan with no heatsink

Thanks for your reply :) My fan is pulling air from the case instead of pushing, I've read that is more effective. Is this still the case, when running with no heatsink? Positive or Negative air pressure, that is the question. My view, I use positive air pressure over negative air pressure because,...
by Idahowalker
Thu Oct 18, 2018 11:48 am
Forum: Beginners
Topic: How to make a non-blocking delay on Tkinter?
Replies: 8
Views: 166

Re: How to make a non-blocking delay on Tkinter?

import threading import RPI.GPIO as GPIO import time iOneButtonPin = 20 iTwoButtonPin = 21 iButton = 0 def fButtonPressCallback( iChannel ) global iButton iButton = iChannel oEventButton.set() def fPush_buttons(): while ( not bEndOfTheWorld ): if ( running == True ) and ( iButton == iOneButtonPin )...
by Idahowalker
Wed Oct 17, 2018 12:52 pm
Forum: Beginners
Topic: How to make a non-blocking delay on Tkinter?
Replies: 8
Views: 166

Re: How to make a non-blocking delay on Tkinter?

Consider using the GPIO.add_event_detect(channel, GPIO.RISING, callback=my_callback, bouncetime=200) bouncetime to delay the responsiveness of the switch press. I, out of curiosity, tested out the idea with using a 32kHz interrupt routine. I took the frequency of 16kHz got the time period, used that...
by Idahowalker
Tue Oct 16, 2018 11:01 pm
Forum: Python
Topic: Driving multiple stepper motors with Python
Replies: 13
Views: 346

Re: Driving multiple stepper motors with Python

Without looking at the code would a Y-connector cable work?
by Idahowalker
Tue Oct 16, 2018 12:43 am
Forum: Python
Topic: [SOLVED]32kHz interrupt
Replies: 6
Views: 194

Re: [SOLVED]32kHz interrupt

I mounted a fan over the top of the CPU heat sink. The temperature warning went away and CPU utilization dropped to 27%.
by Idahowalker
Fri Oct 12, 2018 4:37 pm
Forum: Automation, sensing and robotics
Topic: Using RPi GPIOs as Low Speed Analog I/O
Replies: 15
Views: 475

Re: Using RPi GPIOs as Low Speed Analog I/O

I’ve pretty much given up on additional passive filtering because I figure the noise is internal to the processor (although the wiring could be neater – but its one Hertz), unless anyone has ideas… Send the noise through a inverter and feed it back into the sample. Might want to send the sample thr...
by Idahowalker
Fri Oct 12, 2018 1:36 am
Forum: Beginners
Topic: Pir sensor with raspberry pi 3
Replies: 4
Views: 103

Re: Pir sensor with raspberry pi 3

Perhaps 2 detectors would work a lot better, when you figure out what your issue. I use, as a 2nd sensor, a Microwave motion detector in conjunction with my primary sensor to give 2 degrees of detection. Microwave motion detectors, such as a Icstation RCWL-0516 Microwave Radar Detector are low cost,...
by Idahowalker
Thu Oct 11, 2018 10:50 pm
Forum: Python
Topic: Periodically update DS3231 RTC with NTP
Replies: 10
Views: 180

Re: Periodically update DS3231 RTC with NTP

The DS3231 is, supposed to be accurate to +- 2min per year. I'd say if this is not accurate enough for a week or two, not connected to the internet, use a GPS module instead. Something like the Adafruit Ultimate GPS, which has a RTC, just add battery, has a low operating current requirement. I run a...
by Idahowalker
Thu Oct 11, 2018 5:35 pm
Forum: Python
Topic: Help with 128x64 LCD
Replies: 6
Views: 182

Re: Help with 128x64 LCD

I use this code to comm with-an OLED #!/usr/bin/env python # Substantially derived from code by (c) 2015 Richard Hull The MIT License (MIT) # https://github.com/rm-hull/ssd1306: # "Permission is hereby granted, free of charge, to any person obtaining a copy # "of this software and associated documen...
by Idahowalker
Thu Oct 11, 2018 5:15 pm
Forum: Other projects
Topic: making a digital piano : is the rpi fast enough ?
Replies: 13
Views: 405

Re: making a digital piano : is the rpi fast enough ?

If an Arduino can do it https://blog.arduino.cc/2018/10/08/casi ... d-fingers/, a Pi should be able to do it better.
by Idahowalker
Thu Oct 11, 2018 11:51 am
Forum: Automation, sensing and robotics
Topic: Using RPi GPIOs as Low Speed Analog I/O
Replies: 15
Views: 475

Re: Using RPi GPIOs as Low Speed Analog I/O

(very nonlinear - my next post will go through the equations for this part, probably tomorrow am). Thanks The last time I put together a A:D converter, it looked a whole lot like this but without the LED's. https://www.seas.upenn.edu/~ese206/labs/adc206/Image5.gif You can be sure, I'll be following...
by Idahowalker
Thu Oct 11, 2018 12:32 am
Forum: Automation, sensing and robotics
Topic: Using RPi GPIOs as Low Speed Analog I/O
Replies: 15
Views: 475

Re: Using RPi GPIOs as Low Speed Analog I/O

Something to consider. On the measurement node. Between measurements, bring the RPi input to a high impermanence state or remove the connection by opening the connection (a bilaterial switch) to the cap with a electronic switch, also, open the input to the cap, and short the sampling cap to ground t...
by Idahowalker
Wed Oct 10, 2018 8:26 pm
Forum: Python
Topic: [SOLVED]32kHz interrupt
Replies: 6
Views: 194

Re: 32kHz interrupt

Based on the postings in this thread https://www.raspberrypi.org/forums/viewtopic.php?t=26907 a 32khz input does not sound overly ambitious. You have a lot going on in your code. Have you tried a simple experiment with code that only handles the input of the 32 khz signal and nothing else? Somethin...
by Idahowalker
Wed Oct 10, 2018 8:15 pm
Forum: Python
Topic: [SOLVED]32kHz interrupt
Replies: 6
Views: 194

Re: 32kHz interrupt

Nutzzzzz! This code takes up > 30% of the cpu time handling a 32kHz interrupt. import RPi.GPIO as GPIO import time iPinInt = 21 GPIO.setmode(GPIO.BCM) def f32K( iChannel ): print("eek") return; GPIO.setup( iPinInt, GPIO.IN) GPIO.add_event_detect( iPinInt, GPIO.RISING, callback=f32K) time.sleep(100) ...
by Idahowalker
Wed Oct 10, 2018 6:00 pm
Forum: Python
Topic: [SOLVED]32kHz interrupt
Replies: 6
Views: 194

[SOLVED]32kHz interrupt

Just playing around, I enabled the 32jHz oj my DS3231 RTC and added on some code to handle the 32K signal as an interrupt. In short order cpu use jumps to > 50% and the red sign of doom shows up. I would think the RPI-B would handle a 32kHz-interrupt? import serial import RPi.GPIO as GPIO ##import s...
by Idahowalker
Sun Oct 07, 2018 9:49 pm
Forum: Python
Topic: Periodically update DS3231 RTC with NTP
Replies: 10
Views: 180

Re: Periodically update DS3231 RTC with NTP

I use a DS3231 RTC. I have programmed the RTC to provide a 1PPS interrupt to a Python application. I recommend that, before the RTC is set to be used by the OS set up the alarms or interrupts before the OS locks you out. Once the RTC has its settings set then add it to the OS. This link should answe...
by Idahowalker
Sat Oct 06, 2018 7:31 pm
Forum: Beginners
Topic: Measuring speed with a Pi
Replies: 7
Views: 244

Re: Measuring speed with a Pi

I want a device that measures the speed of a repetition of a barbell in a gym environment. I am only concerned with speed on the one plane - no interest in trying to track horizontal movements. Is this something that could be done with a Pi? In terms of hardware I envisioned a cable reel that could...
by Idahowalker
Sat Oct 06, 2018 2:47 am
Forum: Python
Topic: imports and classes
Replies: 3
Views: 127

Re: imports and classes

Douglas6 wrote:
Sat Oct 06, 2018 1:09 am
Python recognizes what files are imported, and does not import them again.
Thank you, very much, for that bit of info.
by Idahowalker
Sat Oct 06, 2018 12:40 am
Forum: Python
Topic: imports and classes
Replies: 3
Views: 127

imports and classes

In theory: In the main code I import time. In a class that is in another module, that I import, time is imported. It makes sense, to me, that if I import time, before I import the class, then I do not need for the class to import time., correct? Also, if time is imported once and the class is callin...
by Idahowalker
Fri Oct 05, 2018 9:47 pm
Forum: Python
Topic: No module named 'smbus' on Python3.6.2
Replies: 18
Views: 6456

Re: No module named 'smbus' on Python3.6.2

djdan_23 wrote:
Sun Sep 10, 2017 12:39 pm
Could anyone tell me what is wrong. Thanks
Just for fun, can you put

Code: Select all

import serial
as the top entry and do you get a no module named serial found when you try to run the code?
by Idahowalker
Fri Oct 05, 2018 9:03 pm
Forum: Automation, sensing and robotics
Topic: Powerful servo motor ?
Replies: 4
Views: 191

Re: Powerful servo motor ?

i_like_raspberry wrote:
Fri Oct 05, 2018 6:18 pm

It says full metal gear ! That sounds promising ! Thank you so much for the tip ! ! !
You are welcome.
by Idahowalker
Fri Oct 05, 2018 1:17 pm
Forum: Advanced users
Topic: External led event on if/then previous gpio status
Replies: 4
Views: 83

Re: External led event on if/then previous gpio status

I figure that if one was to use your way of blinking an LED one would want to set the GPIO pin high and then low? GPIO.output(4,GPIO.HIGH) In both the On and Off code setting the GPIO 4 to the same state will leave the LED on or off, depending how it is wired. In one of the scripts you need to chang...
by Idahowalker
Fri Oct 05, 2018 12:30 am
Forum: Troubleshooting
Topic: RPi 3 B+ downloaded IDE doesn't upload correct to arduino
Replies: 3
Views: 110

Re: RPi 3 B+ downloaded IDE doesn't upload correct to arduino

You are welcome.

I have a Arduino connected to myPi through the serial port. I use the Arduino to take sensor and LIDAR readings as well as torque the 3 servos. myPi makes the decisions. Good luck.

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