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by blimpyway
Sun Feb 23, 2020 1:31 pm
Forum: Automation, sensing and robotics
Topic: MPU-9250 Magnetometer Wide Range of Values
Replies: 3
Views: 109

Re: MPU-9250 Magnetometer Wide Range of Values

The magnetometer in 9250 is meant to detect earth's magnetic field intensity and direction. That's one reason you will probably never reach a place where it reports zero. You should not expect that. Being quite sensitive it also is easily affected by nearby functioning power equipment, being either ...
by blimpyway
Fri Feb 14, 2020 12:54 am
Forum: Automation, sensing and robotics
Topic: Low Cost Data Glove with a Raspberry Pi
Replies: 2
Views: 115

Re: Low Cost Data Glove with a Raspberry Pi

That looks cool. I would drop thanos gems infinitely irrelevant stuff in the description and provide some actual technical details instead. What it does, how, what kind of sensors it uses. Aand post same technical details here too. "data glove" doesn't mean anything. I handle my data without gloves.
by blimpyway
Fri Feb 14, 2020 12:39 am
Forum: Automation, sensing and robotics
Topic: How to send Gcode to TMC5160s
Replies: 2
Views: 92

Re: How to send Gcode to TMC5160s

why bother? a cheap arduino cnc shield would run G code for several stepper motors.
by blimpyway
Wed Feb 12, 2020 1:59 am
Forum: Automation, sensing and robotics
Topic: 12v door lock using usb port
Replies: 2
Views: 151

Re: 12v door lock using usb port

The pictures you linked reveal no specifications about currents/power needed. Not even producer names or part numbers - assuming you expect someone here is kindly willing to search them instead of you. How much current you can draw from the USB port depends more on how powerful your USB supply is, m...
by blimpyway
Wed Feb 12, 2020 1:46 am
Forum: Automation, sensing and robotics
Topic: Interfacing a Raspberry Pi board with LewanSoul LeArm
Replies: 6
Views: 229

Re: Interfacing a Raspberry Pi board with LewanSoul LeArm

The reason you got little feedback might be you didn't mentioned what a lewansolo is, what it is supposed to do and how
by blimpyway
Mon Feb 10, 2020 10:05 pm
Forum: Automation, sensing and robotics
Topic: Tennis ball collector
Replies: 24
Views: 1146

Re: Tennis ball collector

Different light settings should be approachable in a simpler way than tensorflow.. e.g. see this tutorial which uses only color matching https://www.pyimagesearch.com/2015/09/14/ball-tracking-with-opencv/ No need to detect circles or neural networks - anything matching colour, height/width aspect ra...
by blimpyway
Mon Feb 10, 2020 7:31 pm
Forum: Automation, sensing and robotics
Topic: Logging newton meter from luggage scales
Replies: 2
Views: 99

Re: Logging newton meter from luggage scales

Google "HX711 arduino" and/or "HX711 raspberry pi". And any tutorial on load cell + wheatstone bridge measurement to understand what it does.
by blimpyway
Mon Feb 10, 2020 5:50 pm
Forum: Python
Topic: Getting started with pyserial
Replies: 2
Views: 124

Re: Getting started with pyserial

You should also beware you can use directly Pi's own serial line if you disable console login in /boot/cmdline.txt without the need of an usb-serial adapter. That would also keep the usb port available. PS it seems you can enable a second uart on GPIO header if you want to keep logins on ttyAMA0 for...
by blimpyway
Mon Feb 10, 2020 5:36 pm
Forum: Python
Topic: flask/python/html... want to publish to mqtt when slider is moved
Replies: 1
Views: 134

Re: flask/python/html... want to publish to mqtt when slider is moved

That's python not php. Since there-s little reason the blinder limits to change frequently you need a way to either: - query their limit values on flask's start up. And whenever these limits change have flask notified. - shave blinders end continuously (e.g.every 30 seconds) messages with their curr...
by blimpyway
Mon Jan 06, 2020 12:23 am
Forum: Automation, sensing and robotics
Topic: HC-SR04 ultrasonic distance module won't read any further than 100cm
Replies: 8
Views: 555

Re: HC-SR04 ultrasonic distance module won't read any further than 100cm

for a distance that short you should be able to probe 50 times/sec which gives a 20ms accuracy. There are few ways to make it more accurate - e.g you can use a flat reflective plate (like a gate) and measure continuously the 1.5m gap between sensor and reflector. The difference between a fixed rigid...
by blimpyway
Mon Jan 06, 2020 12:04 am
Forum: Python
Topic: Python library to get EXIF tags from camera?
Replies: 6
Views: 586

Re: Python library to get EXIF tags from camera?

you can execute exif utility and read its output.

Code: Select all

$ sudo apt-get install exif 


$ exif -m file.jpg
by blimpyway
Sun Jan 05, 2020 11:56 pm
Forum: Python
Topic: Converting this Arduino code to Python
Replies: 4
Views: 5977

Re: Converting this Arduino code to Python

You can just leave the speed sensing running on arduino (pro mini, nano) and read its serial printed values in python, either Pi or PC, laptop.
by blimpyway
Fri Dec 27, 2019 10:54 am
Forum: Python
Topic: How to synchronize data on txt files between raspberrys
Replies: 16
Views: 657

Re: How to synchronize data on txt files between raspberrys

... or just don't, use mqtt (message queue) to broadcast state updates and trace them independently on each pi.

Same thing could be use to query current state - needed when one of the PI-s boots up. Or negotiate a "master Pi" - which one is responsible with the overall state updates.
by blimpyway
Sat Dec 21, 2019 6:56 am
Forum: Other projects
Topic: Solar camera timelapses with raspberry pi zero
Replies: 2
Views: 341

Re: Solar camera timelapses with raspberry pi zero

It's good you did not mention what camera, schematics, which os versions you upgraded from or to, what software you use for this or which kernel module isn't loading.

That would make it a too simple riddle.
by blimpyway
Mon Dec 16, 2019 5:44 am
Forum: Automation, sensing and robotics
Topic: pizza vending machine
Replies: 5
Views: 421

Re: pizza vending machine

Contrary to appearances, this is not a complicated program :) Does it have any user interface? Buttons, knobs, timer, power settings? Besides, I only know PHP. But not enough to control GPIO pins of RPi. I don't know PHP but I would learn it if I'll be able to also write arm assembly code afterwards.
by blimpyway
Mon Dec 16, 2019 5:27 am
Forum: Automation, sensing and robotics
Topic: Train engine direction and number detection and reporting
Replies: 5
Views: 472

Re: Train engine direction and number detection and reporting

Assuming by "train engine number" you actually mean "a number printed on a moving train" , you can start by mounting either an outdoor webcam or a pi + camera + weatherproof case, and using motion detection start collecting footage of passing trains. See if you get usable frames - those which captur...
by blimpyway
Sun Dec 15, 2019 10:00 am
Forum: Automation, sensing and robotics
Topic: Train engine direction and number detection and reporting
Replies: 5
Views: 472

Re: Train engine direction and number detection and reporting

What train? The ones I know do not have engines, locomotives have engines.

What is the camera for?
by blimpyway
Sun Dec 15, 2019 9:44 am
Forum: Automation, sensing and robotics
Topic: pizza vending machine
Replies: 5
Views: 421

Re: pizza vending machine

The control program is written in assembly.
OMG that wasn't a joke! Why?
by blimpyway
Thu Dec 12, 2019 3:38 am
Forum: Other projects
Topic: DCF77 ntp server
Replies: 5
Views: 378

Re: DCF77 ntp server

But still nothing on "screen /dev/ttyAMA0 9600" as root. I am starting to think something is broke............ It is not broke. The screen command expects serial ascii at 9600 baud. The protocol mentioned by g4bcf says: . The output will be a pulse per second with a long pulse reperesenting a binar...
by blimpyway
Thu Dec 12, 2019 3:08 am
Forum: Automation, sensing and robotics
Topic: 433Mhz boards
Replies: 4
Views: 328

Re: 433Mhz boards

well, the first one mentions a pdf instructions doc. That should tell you what it can and can not do.

A LoRa module might be able to talk with other LoRa devices. Like smart meters.
by blimpyway
Thu Dec 12, 2019 2:13 am
Forum: Automation, sensing and robotics
Topic: installing OpenCV issues
Replies: 3
Views: 408

Re: installing OpenCV issues

if you need python3.6 with opencv 3.3 an easy way to install it packed together with lots of other stuff (numpy, scipy, scikit learn, jupyter notebooks, pandas, etc..) is berryconda.

Beware it will add almost 1.5GBytes to your SD card.
by blimpyway
Thu Dec 12, 2019 1:56 am
Forum: Automation, sensing and robotics
Topic: 433Mhz boards
Replies: 4
Views: 328

Re: 433Mhz boards

my equipments using DIO 1. What is DIO 1 ? These are apples and oranges. The second one is a LoRa communication module, accessible via serial communication. The first one... is not. The seller says there is some documentation on how to use it to communicate with other, generic 433MHz devices. I dou...
by blimpyway
Mon Dec 09, 2019 12:23 pm
Forum: Python
Topic: Picamera offline installation
Replies: 2
Views: 245

Re: Picamera offline installation

Smart phone with 3/4G + hotspot?

Get/borrow another PI with internet access, do there the installation, (multiply the SD if more than one) then use the SD(s) on the remote Pi(es)?
by blimpyway
Sat Dec 07, 2019 12:02 am
Forum: Other projects
Topic: Water temperature and pump control for pond - how?
Replies: 3
Views: 472

Re: Water temperature and pump control for pond - how?

If you look for reliable, use an arduino with a temperature sensor and a pair of relay module.

You can make it report state (temperature, relay states) later by serial to a Pi or ESP8266, just keeping the control loop on a simpler device makes the whole assembly much more reliable.
by blimpyway
Thu Nov 28, 2019 6:46 am
Forum: Automation, sensing and robotics
Topic: HX711 and weight cell don't work
Replies: 7
Views: 491

Re: HX711 and weight cell don't work

The load cell in your image should be a full wheatstone bridge. From colors my guess the connection should be: red -> E+ black -> E- white, yellow -> to A+ and A-, order irrelevant (you switch these two to get negative or positive readings) But best way to be sure is to measure the resistance betwee...

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