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by Idahowalker
Thu Dec 06, 2018 5:39 pm
Forum: Troubleshooting
Topic: UART can't send more than 1 byte at once
Replies: 4
Views: 384

Re: UART can't send more than 1 byte at once

You may also want to consider your GPS sequence of events for a good NEMA sentence. You might need something like a check once a milli second to do a GPS.read(). If data is present then you, may want to do a GPS.newNMEAreceived(), next do a GPS.parse(GPS.lastNMEA(), and finally check for a fix. If y...
by Idahowalker
Thu Dec 06, 2018 5:27 pm
Forum: Beginners
Topic: Emitting Ultrasonic Sounds
Replies: 23
Views: 986

Re: Emitting Ultrasonic Sounds

One could use an array of ultrasonic devices for higher power output. https://www.youtube.com/watch?v=7lyVr66aAds With a little added circiruty the array of ultrasonic devices can be converted into a phased array. With a phased array you can then simulate array rotation, perhaps even getting near 1...
by Idahowalker
Thu Dec 06, 2018 12:58 pm
Forum: Automation, sensing and robotics
Topic: Object detection / surface scanning
Replies: 11
Views: 1194

Re: Object detection / surface scanning

alright i think i have an idea. but 1st can someone tell me if i can connect multiple ir sensors to one pi and preferrably differentiate between them? Untitled897979798798.png heres what i thought might work. what do you guys think? i am still not sure about increasing the resolution / accuracy and...
by Idahowalker
Thu Dec 06, 2018 12:30 pm
Forum: Beginners
Topic: Emitting Ultrasonic Sounds
Replies: 23
Views: 986

Re: Emitting Ultrasonic Sounds

One could use an array of ultrasonic devices for higher power output.


https://www.youtube.com/watch?v=7lyVr66aAds
by Idahowalker
Mon Dec 03, 2018 10:10 pm
Forum: Beginners
Topic: Just a little humble direction!
Replies: 12
Views: 910

Re: Just a little humble direction!

You may consider something other then using the Python 3(IDLE), especially if you think you'll be poking into multiprocessor operations. Thje Python 3(IDLE) does not work with multiprocessing. Thonny works great with multiprocessing and the Thonny folks just put out a upgrade. Just 'saying.'
by Idahowalker
Mon Dec 03, 2018 5:53 pm
Forum: Beginners
Topic: is a Raspberry Pi 3A the best PI for building a home based radio telescope?
Replies: 7
Views: 684

Re: is a Raspberry Pi 3A the best PI for building a home based radio telescope?

I have just the above mentioned item free with the December issue The MagPi. I am about to start a physics degree specialising in Astronomy and Planetary Science. A project I would like to do involves building a home based radio telescope using my laptop and a Raspberry Pi. Is the Raspberry Pi3A th...
by Idahowalker
Sat Dec 01, 2018 9:00 pm
Forum: Troubleshooting
Topic: Interrupt bouncing by using Accelerometer DATA_READY Interrupt
Replies: 3
Views: 250

Re: Interrupt bouncing by using Accelerometer DATA_READY Interrupt

First, I am not using the device you are using. I fugre many of such devices have some of the same features. On a MPU6050, I used interrupts for a bit. What I did was set the internal registers to hold the data till, after setting a bit in a different register that the data has been read and send an...
by Idahowalker
Tue Nov 27, 2018 6:54 pm
Forum: Python
Topic: 12V Simple Pulse detection and count on Pi3 help12
Replies: 13
Views: 1865

Re: 12V Simple Pulse detection and count on Pi3 help12

An opto-isolator between the 12V signal and the RPi.GPIO
by Idahowalker
Mon Nov 26, 2018 12:50 pm
Forum: Python
Topic: How to update variable value in one line
Replies: 6
Views: 408

Re: How to update variable value in one line

Is the end of input a carriage return? Can yo press 1 and then 2 without pressing enter and the number printing? If each character is being echoed with each key pressed then do not print until a character of your choice has been entered and all other button presses are concatenations of keyboard pre...
by Idahowalker
Mon Nov 26, 2018 12:34 pm
Forum: Troubleshooting
Topic: Hanging in background causing failures. Swappiness? Cron?
Replies: 20
Views: 1877

Re: Hanging in background causing failures. Swappiness? Cron?

Perhaps, you might want to be a bit more granular with your troubleshooting by drilling down into the routines running your program. Start with the Python code and add in some 'try-catch-finally" statements and have those statements logged in some fashion.
by Idahowalker
Sun Nov 25, 2018 1:44 am
Forum: Automation, sensing and robotics
Topic: What to do when you've outgrown Raspberry Pi?
Replies: 1
Views: 1164

Re: What to do when you've outgrown Raspberry Pi?

I still use a RPi. My changes have been to go with a Arduino DUE, ESP32's, and STM32 boards using a RTOS (Real Time Operating System) on those devices. I use the Pi for decision making. The DUE, 3.3V, runs at 80MHz and with the uMT RTOS makes a great data collection companion with the RPi. The low e...
by Idahowalker
Thu Nov 22, 2018 10:50 pm
Forum: Advanced users
Topic: Broken Gpio
Replies: 13
Views: 2344

Re: Broken Gpio

This opto isolated board relay board would work.

https://www.amazon.com/Raspberry-Pi-Exp ... lay+module
by Idahowalker
Thu Nov 22, 2018 2:48 pm
Forum: Advanced users
Topic: Broken Gpio
Replies: 13
Views: 2344

Re: Broken Gpio

Entering the words "circuit operate relay with raspberry pi" into your favorite on-line search engine would net results like these: http://www.susa.net/wordpress/wp-content/uploads/2012/06/Relay-Sample.png http://2.bp.blogspot.com/-8XPDmQ79eLc/UWiY4TiNEqI/AAAAAAAABng/qDoshud3Uls/s1600/Circuit.png
by Idahowalker
Thu Nov 22, 2018 3:33 am
Forum: Advanced users
Topic: Broken Gpio
Replies: 13
Views: 2344

Re: Broken Gpio

This is how i have connected.raspberry relay.png Ok, so you got the relay board connected to RPi 5V and you are controlling the relay board ( D1) from a 3.3V GPIO pin, RPi-J8-40 (GPIO21). I am guessing that you are sending either a 1 or a 0 out of GPIO21 to enable and disable the relay? I'd not dri...
by Idahowalker
Wed Nov 21, 2018 6:08 pm
Forum: Beginners
Topic: GPIO pulse in nanoseconds
Replies: 7
Views: 1204

Re: GPIO pulse in nanoseconds

At that frequency the latency of the code to change the state of the GPIO pin and the overhead of other taskings should be sufficient delay. I've only ran a GPIO interrupt at 400kHz using Python. The only code in the ISR was an evet trigger, to some code being run on another core and I used semaphor...
by Idahowalker
Wed Nov 21, 2018 4:59 pm
Forum: Beginners
Topic: GPIO pulse in nanoseconds
Replies: 7
Views: 1204

Re: GPIO pulse in nanoseconds

Hey, I try to interact with a TLC5940 via C. I use Rapsbian as OS and I am not sure how I can realize something like pulse(int nanoseconds){ setPinOutHigh sleep(nanoseconds) setPinOutLow sleep(nanoseconds) } The timing diagram requires for example a period of at least 3ns for some signals. So is na...
by Idahowalker
Wed Nov 21, 2018 12:20 pm
Forum: Python
Topic: Detecting system crash (not clean shutdown) with python
Replies: 2
Views: 660

Re: Detecting system crash (not clean shutdown) with python

One of the library's I use to interface with a device, occasionally, produces an I/O error. Once the I/O error is produced the behavior of the device library is to crash and not recover. I have sub classed the device library and when the device library crashes the class object is set to None. On the...
by Idahowalker
Tue Nov 20, 2018 10:10 pm
Forum: Advanced users
Topic: Broken Gpio
Replies: 13
Views: 2344

Re: Broken Gpio

Did you have those relays directly powered by the RPI?
by Idahowalker
Tue Nov 20, 2018 6:20 pm
Forum: Python
Topic: Code for Non-invasive Current Probe 100A
Replies: 9
Views: 2526

Re: Code for Non-invasive Current Probe 100A

How about posting the code, in code tags, for us to look at? It would make answering questions about code a bit easier with a reference frame.
by Idahowalker
Mon Nov 19, 2018 3:59 pm
Forum: Python
Topic: multithreading with omxplayer
Replies: 2
Views: 641

Re: multithreading with omxplayer

Use Threading events. Inside each thread, at the start, you can place a threading event that waits until triggered. Thread 1 can be started and thread 1 runs into the threading event and waits. Thread 2 can be started and thread 2 runs into the threading event and waits. After both threads are creat...
by Idahowalker
Sun Nov 18, 2018 3:46 pm
Forum: Python
Topic: Accessing IO in new class
Replies: 18
Views: 1635

Re: Accessing IO in new class

I have classes, threads, and a multiprocess that uses the GPIO pins all with out giving error.

In the main code, I have a function that sets up the GPIO pins, states, and callbacks. This code, to setup GPIO, runs before any threading, class instantiations or, multiprocess are started. East-peasy.
by Idahowalker
Sun Nov 18, 2018 3:36 pm
Forum: Beginners
Topic: USB Serial ports on RPI 3
Replies: 14
Views: 1774

Re: USB Serial ports on RPI 3

The Arduino way.

Open up the Arduino IDE. Look at the ports available, close the Arduino IDE, plug in a Arduino, open the Arduino IDE, now you know which serial port the Arduino is on. Plug in Arduino, open new project, open port, now you know which port the 2nd Arduino is on.
by Idahowalker
Sat Nov 17, 2018 6:10 pm
Forum: Python
Topic: UpdateThonny
Replies: 8
Views: 1397

Re: UpdateThonny

Last night, using Synaptic, I got a Thonny update.
by Idahowalker
Tue Nov 13, 2018 10:49 pm
Forum: Python
Topic: building a recognition machine with rpi3
Replies: 60
Views: 7054

Re: building a recognition machine with rpi3

Have 'you' considered a optical flow sensor? I'm not going to point you to the sources but typing the proper characters into your favorite search engines can do the trick. Using a paper wrote by some professor on how a bumble bee sees, some Arduino users have been looking into how to use multiple op...
by Idahowalker
Mon Nov 12, 2018 6:31 pm
Forum: Beginners
Topic: Antenna setup for aircraft signal advice
Replies: 23
Views: 1787

Re: Antenna setup for aircraft signal advice

I was going to add that instead of cutting the braided shield spread it out to form a ground plane. I saw the pie tine suggestion and thought 'Oi! great idea' to split the braided shield into 4 sections and spread unto the pie tin or other piece of metal; you might end u[p soldering the braid to th...

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