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by Idahowalker
Mon Oct 29, 2018 12:20 am
Forum: Python
Topic: GPIO Callbacks and threads - how to signal between threads
Replies: 4
Views: 876

Re: GPIO Callbacks and threads - how to signal between threads

I was looking at that..I am not familiar with Python and threading so reading more. also just realized, I cannot execute the function on the callback thread as that (from what I have read) will block all other callbacks until the current one completes. Try to do as little as possible within a callb...
by Idahowalker
Sun Oct 28, 2018 10:00 pm
Forum: Python
Topic: GPIO Callbacks and threads - how to signal between threads
Replies: 4
Views: 876

Re: GPIO Callbacks and threads - how to signal between threads

threading.events may be one way.
by Idahowalker
Sun Oct 28, 2018 9:56 pm
Forum: Beginners
Topic: Where to get Sensors (What do I need to know)
Replies: 13
Views: 1260

Re: Where to get Sensors (What do I need to know)

Research. Say, you want a barometric sensor. Type into your favorite search engine something like 'Raspberry Pi barometric sensor. See what comes up. Jot those sensors down and go looking for their datasheets. No datasheet, cross the item off the list. Now, try a search for 'SensorOfChoice Python Li...
by Idahowalker
Sat Oct 27, 2018 5:39 pm
Forum: Beginners
Topic: How do I configure the low-pass filter on an MPU-6050 accelerometer?
Replies: 2
Views: 917

Re: How do I configure the low-pass filter on an MPU-6050 accelerometer?

Here is some code that may help [''' Read Gyro and Accelerometer by Interfacing Raspberry Pi with MPU6050 using Python http://www.electronicwings.com **************************************************************** mpu6050 rpi3 scl to RPiJ8-5 sda to RPiI8-3 GND to GND VCC to 3.3 volts check if I2C u...
by Idahowalker
Fri Oct 26, 2018 3:12 pm
Forum: Troubleshooting
Topic: ESP32 development from a raspberry
Replies: 3
Views: 566

Re: ESP32 development from a raspberry

I have used the Arduino IDE to communicate with a ESP32 from the RPi, it can be done. But the ESP32 cpp file, to create the code to upload to the ESP32, is made for the Intel uProcessor family. Whiles the Arduino IDE will go through the motion of uploading to the ESP32, it fails. To get the cpp file...
by Idahowalker
Fri Oct 26, 2018 11:42 am
Forum: Automation, sensing and robotics
Topic: ADXL345 Accelerometer output
Replies: 4
Views: 1927

Re: ADXL345 Accelerometer output

After reading the high bits and the low bits from the unit, the bits will need to be combined, in the same step I twos compliment the data before applying the scale factor. For accelerometers, it is, when applying the scale factor the time to apply any offsets and drift rates that were obtained duri...
by Idahowalker
Thu Oct 25, 2018 11:06 am
Forum: Python
Topic: Need Help Counting Pulses - PWM Tach Signal
Replies: 5
Views: 1274

Re: Need Help Counting Pulses - PWM Tach Signal

Idahowalker, unfortunately electrical is not my strong suit. What size resistor and where do I put it? I been using, for the RPi 1M ohm 1/4 watt for the pull up_down resistors.. Put one end of the resistor to the output of the GPIO pin and the other to either circuit ground or the 3.3V supply rail,...
by Idahowalker
Wed Oct 24, 2018 9:52 pm
Forum: Python
Topic: Need Help Counting Pulses - PWM Tach Signal
Replies: 5
Views: 1274

Re: Need Help Counting Pulses - PWM Tach Signal

Put a real pull up or down resistor on the interrupt pin and do not use the provided pull up down resistor.
by Idahowalker
Wed Oct 24, 2018 9:39 pm
Forum: Troubleshooting
Topic: RTC DS3231 gets old shutdown time on boot
Replies: 2
Views: 393

Re: RTC DS3231 gets old shutdown time on boot

A few ideas, is there another device on the same I2C address? I know the MPU6050 and the DS3231 share the same default address, to have both on the same system, I changed the address of the MPU6050. Can you peek into the registers? There is a register setting to stop the crystal (clock) whiles on ba...
by Idahowalker
Tue Oct 23, 2018 11:02 pm
Forum: Advanced users
Topic: How to send file by the serial com line ?
Replies: 5
Views: 1496

Re: How to send file by the serial com line ?

You should be able to use FTP over the serial line. Just a guess. I did get a lot of hits when, into my favorite search engine, I typed some words like "raspberry pi serial file transfer protocols."
by Idahowalker
Tue Oct 23, 2018 8:35 pm
Forum: Beginners
Topic: Increase current capability of 3.3v PWM
Replies: 3
Views: 323

Re: Increase current capability of 3.3v PWM

b4tn wrote:
Tue Oct 23, 2018 5:12 pm
Thank you!
The Xistor will invert the PWM signal.
by Idahowalker
Mon Oct 22, 2018 12:36 pm
Forum: Automation, sensing and robotics
Topic: Measuring UBEC output voltage
Replies: 2
Views: 1123

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: 251

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: 1396

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: 919

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: 919

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: 2836

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: 646

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: 2077

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: 496

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: 11
Views: 1681

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: 854

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: 2692

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: 2077

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: 2077

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...

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