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by blimpyway
Thu Apr 18, 2019 8:20 pm
Forum: Other projects
Topic: Power supply for mobile project.
Replies: 2
Views: 73

Re: Power supply for mobile project.

The projector alone, at 270W, will depelete a 48Wh battery in 48 Wh/270W = 0.1777 h = 10 minutes and 40 seconds.
by blimpyway
Thu Apr 18, 2019 8:13 pm
Forum: Other projects
Topic: EDS
Replies: 1
Views: 67

Re: Excavator Depth Sensor

An IMU includes XYZ accelerometers which you can use to measure inclination, I do not know how suitable are they for your problem. In order to have some accuracy, it needs to measure when not moving, which means must stop for a second (or even less) the cup in lowest position to get a correct (or at...
by blimpyway
Thu Apr 11, 2019 9:49 am
Forum: Networking and servers
Topic: Connecting an Xbee Pro Module to a Raspberry Pi Zero W
Replies: 1
Views: 57

Re: Connecting an Xbee Pro Module to a Raspberry Pi Zero W

xbees just provide an "wireless wire" serial . That means you use normal UARTs to communicate and xbee pair replaces the actual cable. The module you linked to is no more than an USB to serial adapter which: - is needed by devices which do not have a TTL level serial port but have USBs. More exactly...
by blimpyway
Wed Apr 10, 2019 11:59 am
Forum: Automation, sensing and robotics
Topic: Defining Gps Area
Replies: 5
Views: 153

Re: Defining Gps Area

omegaman477 wrote:
Tue Apr 09, 2019 2:25 pm
...

This Python Library will handle the bulk of the cartesian and Sexagesimal mathematics required. There are similiar libraries for most languages and O/s
...and the library is.. which one?
by blimpyway
Wed Apr 10, 2019 11:44 am
Forum: Automation, sensing and robotics
Topic: DS18B20 network issues after 2 months stable
Replies: 5
Views: 169

Re: DS18B20 network issues after 2 months stable

That totals almost 60meters of cable for a single 1 wire loop. If any problem happens anywhere (interference, bad contact, leakage) it not only affects all sensor readings but it also is quite hard to find it. Split them as you can to get the shortest lines possible, try even 3 loops instead of 2 Th...
by blimpyway
Wed Apr 10, 2019 11:08 am
Forum: Python
Topic: I can't get a process tell me when I'm done using While "p.poll() == None"
Replies: 2
Views: 73

Re: I can't get a process tell me when I'm done using While "p.poll() == None"

That's not a problem of poll() but time.sleep() who does the locking of the whole interpreter. If tk buttons is what you-re complaining about, see this discussion here https://stackoverflow.com/questions/18038604/interacting-with-tkinter-window-during-a-long-process It's a not an issue to be "solved...
by blimpyway
Wed Apr 10, 2019 10:48 am
Forum: Python
Topic: serial readings to tkinter lable?
Replies: 7
Views: 1053

Re: serial readings to tkinter lable?

The b'...' is printed because serial reads in bytes instead of string. So the print function puts b'' just to make you aware you-re printing a bytes type object. the \r and \n have already been explained. You can use strip() to remove leading & trailing newlines and spaces then decode() to convert a...
by blimpyway
Mon Apr 01, 2019 12:22 pm
Forum: Python
Topic: trigger camera from gpio input pulse
Replies: 5
Views: 144

Re: trigger camera from gpio input pulse

If you want your setup to be more flexible you can let arduino print measured speeds on its serial line and have the actual speed threshold set in Pi's python code. So you don't need to re-compile & upload arduino code when you want to change the speed level for camera trigger.
by blimpyway
Mon Apr 01, 2019 12:08 pm
Forum: Python
Topic: PiCamera and DC Motor using MultiProcessing
Replies: 5
Views: 181

Re: PiCamera and DC Motor using MultiProcessing

It could be the camera is opened in main process then there are created (through system's fork) two more processes with the same camera handle, and the camera library has some internal lock/protection against multiple processes accessing the camera instance. What happens if you move camera creation ...
by blimpyway
Fri Mar 29, 2019 9:13 pm
Forum: Automation, sensing and robotics
Topic: How best to control higher voltage relays with 12v/24v coils?
Replies: 26
Views: 797

Re: How best to control higher voltage relays with 12v/24v coils?

You can either - look for relay modules which beside the relays themselves include whatever circuitry is needed to drive them with 3.3 or 5V low power signals, so they can be commanded directly - look for components/schematics which interface between PI's gpio lines and 12 or 24V relay coils. Most i...
by blimpyway
Fri Mar 29, 2019 4:54 pm
Forum: Automation, sensing and robotics
Topic: Making a night surveillance camera
Replies: 5
Views: 229

Re: Making a night surveillance camera

You have to check LED's current/voltage. Pi's gpio pins will only sink a few mA (15mA? not sure need to read the specs).

The 3W LEDs need a 700mA at 1.4-2.6V each. So no way a pi alone without a relay or power transistor could power them.
by blimpyway
Tue Mar 26, 2019 8:48 pm
Forum: Automation, sensing and robotics
Topic: Making a night surveillance camera
Replies: 5
Views: 229

Re: Finding the perfect camera setup for my future Home Assistant/Z-Wave Rasp Pi 3+ setup

You can find both wide angle (fish eye) variants of Pi cameras and you also can attempt to attach wide angle lenses to "normal" PI cameras, e.g. there are various clip-on lenses for phone cameras which could be used. ===== I'm not familiar with home assistant or z-wave. Motion eye is just a linux pa...
by blimpyway
Tue Mar 26, 2019 4:20 pm
Forum: Automation, sensing and robotics
Topic: Display postion (level with MPU6050) of a caravan in a web-app on a smartphone
Replies: 4
Views: 130

Re: Display postion (level with MPU6050) of a caravan in a web-app on a smartphone

I'm currently using a stack with python, gevent, flask, socketio on the Pi side and P5.js on the client side (e.g phone browser). Gevent is an async framework which gives python efficient realtime multitasking capabilities, needed since a single python process needs to serve static web content, to g...
by blimpyway
Tue Mar 26, 2019 2:00 pm
Forum: Automation, sensing and robotics
Topic: Display postion (level with MPU6050) of a caravan in a web-app on a smartphone
Replies: 4
Views: 130

Re: Display postion (level with MPU6050) of a caravan in a web-app on a smartphone

I'm not sure Pi is the right tool for such a narrow purpose device. This needs to be done once every few days with long periods of pause (months) in between. If you don't want PI to draw 200mA (on Pi ZeroW) all that time you need a button somewhere to turn it on/off. Turning it on means also wait Pi...
by blimpyway
Tue Mar 26, 2019 1:44 pm
Forum: Automation, sensing and robotics
Topic: Making a night surveillance camera
Replies: 5
Views: 229

Re: Finding the perfect camera setup for my future Home Assistant/Z-Wave Rasp Pi 3+ setup

Most "natural" camera for PI is a PI camera. And unlike generic USB cams is light on CPU since a lot of image processing is integrated in GPU. "perfect" for this case could be the one that is known to integrate with Pi and is cheap to get. ----- Search for pi motion eye, motioneye os. You can do mor...
by blimpyway
Tue Mar 26, 2019 1:17 pm
Forum: Automation, sensing and robotics
Topic: Raspberry Pi, Arduino and I2C
Replies: 5
Views: 182

Re: Raspberry Pi, Arduino and I2C

No, Arduino can safely work at 3.3V at 8MHz. There are 3.3V 8MHz Pro-minis. And any 5V 16MHz crystal Atmega328 arduino (UNO, Nano, ProMini) can be configured (via avrdude command line + ISP adapter) to run on its 8MHz internal oscillator. And there are people who even powered directly 5V/16MHz ardui...
by blimpyway
Tue Mar 26, 2019 1:11 pm
Forum: Automation, sensing and robotics
Topic: Septic/Sump Automation Project
Replies: 5
Views: 228

Re: Septic/Sump Automation Project

TheLazyIT wrote:
Tue Mar 26, 2019 2:36 am
...
-Anything I may have missed
An user with "lazy" in their name should always check their ideas/solutions against Pareto principle. Is it really worth it?
by blimpyway
Mon Mar 25, 2019 6:46 pm
Forum: Automation, sensing and robotics
Topic: Raspberry Pi, Arduino and I2C
Replies: 5
Views: 182

Re: Raspberry Pi, Arduino and I2C

I2C is master-slave. Various I2C sensors are almost all slaves. Whoever talks to sensors needs to be master, so if you want arduino to talk with sensors then it has to be master. Now if arduino is supposed to (partially compute sensor input and) forward sensor data to PI there are (at leas) three po...
by blimpyway
Sun Mar 24, 2019 4:08 pm
Forum: Automation, sensing and robotics
Topic: Read Data from Pi without WIFI
Replies: 3
Views: 132

Re: Read Data from Pi without WIFI

Another ways would be to

1. use a public/cloud MQTT broker to pass messages between PI and any phone on this planet.

2. Use dynamic IP to have a PI (and its own web server/application) visible to the whole internet and connect to it from any phone/laptop/PC which has internet access.
by blimpyway
Sun Mar 24, 2019 4:03 pm
Forum: Automation, sensing and robotics
Topic: Read Data from Pi without WIFI
Replies: 3
Views: 132

Re: Read Data from Pi without WIFI

In theory it is possible to have IP over bluetooth and have connection setup "magically" whenever phone is within range of a certain bluetooth device (like PI) but unless you find such application already existing on Google Play or Apple store, there-s no way you can do what you want without having ...
by blimpyway
Sat Mar 23, 2019 2:24 am
Forum: Automation, sensing and robotics
Topic: connecting multiple sensors
Replies: 3
Views: 187

Re: connecting multiple sensors

I'd dedicate an arduino nano or pro-mini(*) for all these inputs - - 5 analog lines for flex sensors, - 6 digital lines for contact sensors, - I2C for an accelerometer like mpu6050 (2 lines) And have it print values to PI via ttl serial or usb-serial. Note (*) - normally Pro-mini has only 6 analog i...
by blimpyway
Sat Mar 23, 2019 1:53 am
Forum: Automation, sensing and robotics
Topic: Recommendations for vision system please
Replies: 18
Views: 694

Re: Recommendations for vision system please

I've played with motion detection in OpenCV, I think the code I used can be used/modified for this case, with the discs coloured as in your test. Or with single, round spots on each disc. Being based on motion detection, hopefully would not need calibration or assuming predefined disc positions. ---...
by blimpyway
Fri Mar 22, 2019 10:51 pm
Forum: Automation, sensing and robotics
Topic: Wi-Fi Relay & Raspberry
Replies: 4
Views: 165

Re: Wi-Fi Relay & Raspberry

If you use either an off-the-shelf ESP-8266 relay module like Sonoff, or you make one yourself with an NodeMCU board and several 3.3V relay modules, the firmwares available (Tasmota, ESPurna, etc...) are quite fully functional they don't need an extra raspberry PI to control them. If you want the PI...
by blimpyway
Thu Mar 21, 2019 11:41 pm
Forum: Networking and servers
Topic: Run Shell srcript only once
Replies: 17
Views: 554

Re: Run Shell srcript only once

You should use just the existence of the temporary file as proof the script was already run. And use /tmp for temporary files. A script gone wrong writing too often the SD card... could affect its life. /tmp is in RAM [ -f /tmp/myspecialfile ] || { echo "no /tmp/myspecialfile yet" touch /tmp/myspeci...
by blimpyway
Thu Mar 21, 2019 10:15 pm
Forum: Other projects
Topic: Using an RPi to reduce Power Usage, Off Grid.
Replies: 8
Views: 455

Re: Using an RPi to reduce Power Usage, Off Grid.

pfletch101 wrote:
Tue Mar 19, 2019 3:34 pm
Do you not allow your fridges to be opened at night?! What do any fellow humans who may share your space think about this?!!
For fellow humans could provide a PayPal enabled fridge door opening web page

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