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by henryhanselscott
Thu Feb 16, 2017 5:55 pm
Forum: General discussion
Topic: VNC server freezes
Replies: 0
Views: 495

VNC server freezes

I have a couple of headless pi 3's doing various work. I generally access these units with my cell phone over VNC app on Andriod. Sometimes, if the cell reception is poor and I connect to the pi I loose the connection. When this happens VNC does not get released properly on the pi. After that point,...
by henryhanselscott
Thu Feb 16, 2017 5:05 pm
Forum: General discussion
Topic: Servo Control
Replies: 10
Views: 1990

Re: Servo Control

I work with this type of servo often in industrial controls. Generally speaking, they require a pulse step and a direction input. The motion control profile is generally part of the pulse step train. Operating like this, they are like driving a stepper motor only with closed loop feedback. When figu...
by henryhanselscott
Mon Feb 06, 2017 12:33 pm
Forum: General discussion
Topic: Using under voltage warning for pi shutdown
Replies: 6
Views: 2763

Re: Using under voltage warning for pi shutdown

Thanks for the replies, very useful information. My thought is to have the pi run on a normal 5 volt supply with a battery backup in the case of a power failure. Then when the batteries begin to get low after a power failure the system would shutdown.
by henryhanselscott
Mon Feb 06, 2017 11:00 am
Forum: General discussion
Topic: Using under voltage warning for pi shutdown
Replies: 6
Views: 2763

Using under voltage warning for pi shutdown

Would it be possible to use the under voltage warning to trigger a system shutdown? More specifically, could a python script monitor for low voltage and then use os.system("sudo shutdown -h now") to shutdown with minimal risk of corruption?

Thanks,
Henry
by henryhanselscott
Sun Jan 08, 2017 11:59 am
Forum: General discussion
Topic: mpack email "from" field
Replies: 4
Views: 2353

mpack email "from" field

I am using mpack to send a report from my pi application via a gmail account. This is working perfectly. However email sent from the pi are always from "root" instead of "Henry". So, the receiver of the email sees it as sent from "root". How/where do I edit this property so that email send from my p...
by henryhanselscott
Fri Sep 30, 2016 8:22 am
Forum: General discussion
Topic: Raspbian with Read-only Root
Replies: 191
Views: 90642

Re: Raspbian with Read-only Root

Virtually everything I do with the pi is embedded applications. To combat this I have developed PIC based UPS solutions that add complexity. This is what I have been looking for....THANK YOU!. One linux noob question, after this procedure has been done and then the system is updated and upgraded doe...
by henryhanselscott
Tue Sep 13, 2016 9:22 am
Forum: General discussion
Topic: Quick regarding capabilities.
Replies: 7
Views: 1266

Re: Quick regarding capabilities.

Just for clarity, the pi is TOTALLY capable to of everything that you listed. You will have peripheral support hardware such as relays and input levelers. Also, it will not be a "drag and drop" programming experience. But is is very much a worth while endeavor if your current jog scope allows for so...
by henryhanselscott
Thu Aug 25, 2016 3:16 pm
Forum: General discussion
Topic: Controlling 40 Motors using Pi
Replies: 14
Views: 2592

Re: Controlling 40 Motors using Pi

Another approach is using the pi as a "Front end" and a PLC as the actual controller. I program PLC's everyday and there robustness is undeniable. However, often they lack in the ability to support a sleek GUI for the operator unless you buy a very expensive PLC compatible touch screen. I have used ...
by henryhanselscott
Mon Jul 25, 2016 12:14 pm
Forum: General discussion
Topic: STICKY: USB boot now working on Pi3
Replies: 548
Views: 286007

Re: USB boot now working on Pi3

Not trying to derail the thread but curious about a couple things now that this is possible: 1. Will booting from an external device possibly improve file system corruption issues currently experienced using an SD card when power is interrupted? 2. If booting from an external device, could the SD ca...
by henryhanselscott
Mon Jun 06, 2016 9:09 am
Forum: General discussion
Topic: Time setting on startup with no Internet?
Replies: 17
Views: 4292

Re: Time setting on startup with no Internet?

How can the screensaver know it is out of date when there is no Internet available to check it? I have an application that has the fake HW clock disabled and uses a Dallas 3132 RTC chip for time keeping. https://www.maximintegrated.com/en/products/digital/real-time-clocks/DS3231.html Sometimes on s...
by henryhanselscott
Tue May 31, 2016 9:48 am
Forum: General discussion
Topic: Current Status USB boot Rpi3?
Replies: 2
Views: 1013

Current Status USB boot Rpi3?

Just wondering about the rumored ability of the Pi3 to boot from a USB device. I have a project that could benefit from getting away from the SD card boot and associated failures of the SD card. Few weeks back had a SD card go up in smoke (literally) for no apparent reason. I have had other SD card ...
by henryhanselscott
Mon May 02, 2016 4:29 pm
Forum: General discussion
Topic: Pi stops updating in kiosk mode after 15 mins
Replies: 5
Views: 1186

Re: Pi stops updating in kiosk mode after 15 mins

My code was just poorly written, I was just learning tkinter/Python. I should have been changing just the text property of the widget but instead I was creating a new widget every time that the data updated. They were just stacking on top of each other, even though the physical appearance of the GUI...
by henryhanselscott
Mon May 02, 2016 2:22 pm
Forum: General discussion
Topic: Pi stops updating in kiosk mode after 15 mins
Replies: 5
Views: 1186

Re: Pi stops updating in kiosk mode after 15 mins

Have you tried to open the task manager after a fresh boot and see if the memory is getting used more and more as time goes on? Sounds like a memory leak is killing all your resources. I had this happen a while back when I had a tkinter GUI running and was not properly destroying a widget when it wa...
by henryhanselscott
Fri Apr 29, 2016 12:48 pm
Forum: General discussion
Topic: Anyone good at driving stepper motors
Replies: 23
Views: 4636

Re: Anyone good at driving stepper motors

I am interested in where this goes as well. It would be nice to see a fully pi/simple driver solution. I run lots of steppers in the manufacturing automation world. When doing multi axis motion control, I generally use smart stepper drivers that can receive direction commands via the host comm port ...
by henryhanselscott
Thu Apr 28, 2016 10:00 pm
Forum: General discussion
Topic: Autostart py script
Replies: 26
Views: 4608

Re: Autostart py script

I have no idea why it works, I would also like to hear a definitive answer. My guess is a resource availability/timing issue. This was the only way I could work it out when I went down this same road about a year ago, the project that I was working on had to have this function or it was DOA. I do no...
by henryhanselscott
Thu Apr 28, 2016 3:50 pm
Forum: General discussion
Topic: Need High Accuracy Electronic Target using triangulation
Replies: 37
Views: 8048

Re: Need High Accuracy Electronic Target using triangulation

Before integrating the pi into my project arsenal, micros were my go to weapons. It seems to me that a micro would be much more accurate at this because they are generally deterministic. The pi is fantastic will all the peripherals that it brings to the table, but time critical functions may not be ...
by henryhanselscott
Thu Apr 28, 2016 9:18 am
Forum: General discussion
Topic: Autostart py script
Replies: 26
Views: 4608

Re: Autostart py script

Great! Sorry for the import errors, its been a while since I messed with this.

Henry
by henryhanselscott
Wed Apr 27, 2016 5:48 pm
Forum: General discussion
Topic: Autostart py script
Replies: 26
Views: 4608

Re: Autostart py script

I have had the same struggles and came up with one solution that seems to work all the time. My python script runs in X using tkinter AND it also uses the GPIO. I could find any examples that would make it autostart including all the above helps. So, I created a non GUI, non GPIO python script, made...
by henryhanselscott
Tue Apr 26, 2016 5:27 pm
Forum: General discussion
Topic: SD card on fire !
Replies: 5
Views: 1465

Re: SD card on fire !

Last week had a SD card fail and it went smoking hot also. When I installed the card into my desktop PC had the same reaction. Got new SD card and the pi is happy now. This seems to be a common failure mode.

Henry
by henryhanselscott
Sat Apr 02, 2016 10:48 am
Forum: General discussion
Topic: Rpi3 blue tooth and cell phone keyboard?
Replies: 1
Views: 830

Rpi3 blue tooth and cell phone keyboard?

Never used blue tooth before and was wondering if the blue tooth functionality of the pi3 could be used to interface a cell phone and use the cell phones keyboard to input data into the pi running a python script? Not looking for a play by play how to do it but if possible just point me in the right...
by henryhanselscott
Tue Nov 03, 2015 12:02 pm
Forum: General discussion
Topic: Threading and GPIO ?
Replies: 2
Views: 1076

Threading and GPIO ?

I have a project where it would be beneficial to control and read GPIO pins in the background. For instance, one of my GPIO pins would be used to trigger an ultrasonic sensor and then another another used to read the response time from the sensor. I would like to do this in the back ground continuou...
by henryhanselscott
Mon Oct 05, 2015 11:50 am
Forum: General discussion
Topic: ready access memory retention?
Replies: 3
Views: 717

Re: ready access memory retention?

Is there any particular reason you suspect this data corruption might happen? No, it is just the fact that I did not know if this should be a concern or not. In all my previous experiences building controllers with micros I have written the variable data to flash based memory devices, which is also...
by henryhanselscott
Mon Oct 05, 2015 9:24 am
Forum: General discussion
Topic: ready access memory retention?
Replies: 3
Views: 717

ready access memory retention?

So at the risk of sounding like an idiot, here goes: I have a Python3 script that reads a file on start up, assigns a variable the text data in the file and then closes the file. The script may run for weeks or even months. Is there any risk that the OS will dump or overwrite this area of memory or ...
by henryhanselscott
Mon Sep 28, 2015 5:25 pm
Forum: General discussion
Topic: Maker Faire NYC
Replies: 7
Views: 1144

Re: Maker Faire NYC

No....but headed to the one in Atlanta (Decatur) GA this Saturday. Hoping to see a some cool pi projects there.

Henry
by henryhanselscott
Wed Sep 23, 2015 1:28 pm
Forum: General discussion
Topic: cp -r Rpi2 hangup?
Replies: 2
Views: 542

cp -r Rpi2 hangup?

My Python script uses: os.system("cp -r /media/A/DATA /media/B") I am copying the folder "DATA" located on the "A" USB flash drive to the "B" USB flash drive. The "DATA" folder contains .csv files. This seems to work as expected as the folder and all of its contents are copied to the "B" flash drive...

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