Go to advanced search

by blimpyway
Sat Sep 14, 2019 7:29 pm
Forum: Automation, sensing and robotics
Topic: Proyect: Autonomous robot with a rechargeable batteries
Replies: 2
Views: 71

Re: Proyect: Autonomous robot with a rechargeable batteries

You can find power packs with usb in (for charging) and out (for PI & motors). The motors you mentioned work fine between 3 and 6V, At 4.5-5V you will just get lower top speed. 150rpm instead of 200. Motor drivers might lose another 1V drop.. It depends on the type of driver. For 7.4V you can go the...
by blimpyway
Sat Sep 14, 2019 6:56 pm
Forum: Automation, sensing and robotics
Topic: Basement sensors?
Replies: 4
Views: 155

Re: Basement sensors?

Liquid level in a tank can also be measured with an ultrasonic distance sensor.
I don't know with Pi-s, but on arduino/microcontrollers sub-centimeter precision is possible, because there are no unpredictable interrupts, you can reliably measure time intervals with accuracy of a few microseconds.
by blimpyway
Sat Sep 14, 2019 6:46 pm
Forum: Automation, sensing and robotics
Topic: Using Pi Zero W as a Facial Recognition Middle Man
Replies: 1
Views: 51

Re: Using Pi Zero W as a Facial Recognition Middle Man

Pi Zero has quite decent FPS for its "size". But for facial recognition you don't really need high FPS, just a good picture every couple seconds.

If your idea works or not depends on phone's capabilities (speed, accuracy) to identify humans in a picture.
by blimpyway
Mon Sep 09, 2019 7:22 pm
Forum: Automation, sensing and robotics
Topic: Challenge of Powering Robot 24/7
Replies: 6
Views: 180

Re: Challenge of Powering Robot 24/7

Here is details, schematic, etc. on my existing system and a video of Carl getting on and off his dock

And this is the write up on Carl's current "Find the Dock" using OpenCV"
That's really cool, thank you
by blimpyway
Mon Sep 09, 2019 6:26 am
Forum: Python
Topic: Pi zero w - not able to install packages using pip
Replies: 2
Views: 97

Re: Pi zero w - not able to install packages using pip

pip is quite slow on Pi ZeroW but it works. New connection error seems like a network issue
by blimpyway
Sat Sep 07, 2019 9:46 pm
Forum: Automation, sensing and robotics
Topic: Detecting remote relay closure?
Replies: 3
Views: 129

Re: Detecting remote relay closure?

That wireless switch sensor is not meant to detect currents or voltages but magnetic field of a nearby magnet, when the door/window opens the switch turns on and sends a signal to the base station. So. unless your relay contact results in moving a door. window, drawer, etc... it will be a bit challe...
by blimpyway
Sat Sep 07, 2019 9:39 pm
Forum: Automation, sensing and robotics
Topic: 12 V step motor overheated with ULN2003 controller
Replies: 18
Views: 551

Re: 12 V step motor overheated with ULN2003 controller

ook sorry for that. Just seen the discussion on GND connections Another thing is quite unclear: I then run a program that worked with a 5 V motor , but nothing happened. Or better, the motor was very hot but unresponsive. What did I get wrong? What motor was that? Was it powered through the same ULN...
by blimpyway
Sat Sep 07, 2019 9:20 pm
Forum: Automation, sensing and robotics
Topic: Challenge of Powering Robot 24/7
Replies: 6
Views: 180

Re: Challenge of Powering Robot 24/7

A dc-dc buck converter will efficiently provide 5V to PI from a LiPo's 7.2 or 11V pack They are cheap and small, since Lipo-s are more compact than NiMh you should find some room for them. You need to closely monitor battery voltage to prevent overdischarge. There are also charging equalizers that a...
by blimpyway
Fri Sep 06, 2019 8:48 pm
Forum: Networking and servers
Topic: telnet to serial
Replies: 8
Views: 218

Re: telnet to serial

Despite this is an PI forum. I had good experience using ESP8266 with esp-link firmware to get a TCP to serial connection..

https://github.com/jeelabs/esp-link`

PS however it is a port listener it doesn't actively open sockets to remote servers.
by blimpyway
Fri Sep 06, 2019 8:40 pm
Forum: Networking and servers
Topic: driver for wireless Realtek 8188
Replies: 9
Views: 251

Re: driver for wireless Realtek 8188

You can also post output (actually last ~20 lines only) from dmesg immediately after you insert the dongle in the USB port:

Code: Select all

$ dmesg 
???? 
by blimpyway
Fri Sep 06, 2019 8:28 pm
Forum: Automation, sensing and robotics
Topic: Making a simple robot that follow you.
Replies: 2
Views: 116

Re: Making a simple robot that follow you.

From what I know about opencv, raspberrys while object detection and human detection might work, it won't tell humans apart which one is which so you might end up freaking people out when the robots starts chasing random people around. What seems to work fairly acceptable with raspberrys is colour b...
by blimpyway
Fri Sep 06, 2019 8:04 pm
Forum: Automation, sensing and robotics
Topic: 12 V step motor overheated with ULN2003 controller
Replies: 18
Views: 551

Re: 12 V step motor overheated with ULN2003 controller

SO if I .... Anyway, how do I provide a ground since the ULN2003 does not have pins left (apart for the two for the 5 V input)? Tx See documentation, page 4 https://www.st.com/resource/en/datasheet/uln2001.pdf Pin 8 is ground pin. It has to be connected to both Pi's GND and to the 0V (ground) of th...
by blimpyway
Fri Sep 06, 2019 7:41 pm
Forum: Automation, sensing and robotics
Topic: [SOLVED] How To Get Smooth PWM Control
Replies: 15
Views: 484

Re: [ASK] How To Get Smooth PWM Control

Or, if you power the steering servo from Pi's 5V (or other "weak" supply) it could mess signal to the throttle pwm controller. I know servos can interfere with each other - search for servo jitter problems and how they are solved. Perhaps a servos peak starting currents could influence pwm signal o...
by blimpyway
Tue Sep 03, 2019 9:07 pm
Forum: Automation, sensing and robotics
Topic: Auto Upload to server
Replies: 2
Views: 108

Re: Auto Upload to server

Yes you can, search for git tutorials.
Read github's service agreements, to be sure they are ok to use their servers for general purpose sound file storage.

You may also investigate soundcloud https://stackoverflow.com/questions/908 ... ing-python
by blimpyway
Tue Sep 03, 2019 8:49 pm
Forum: Automation, sensing and robotics
Topic: [SOLVED] How To Get Smooth PWM Control
Replies: 15
Views: 484

Re: [ASK] How To Get Smooth PWM Control

Or, if you power the steering servo from Pi's 5V (or other "weak" supply) it could mess signal to the throttle pwm controller. I know servos can interfere with each other - search for servo jitter problems and how they are solved. Perhaps a servos peak starting currents could influence pwm signal of...
by blimpyway
Tue Sep 03, 2019 8:08 pm
Forum: Automation, sensing and robotics
Topic: Seeking IDEA: Two Cats and Separate Diet Problem
Replies: 5
Views: 158

Re: Seeking IDEA: Two Cats and Separate Diet Problem

Coloured collars might make a vision-based automatic trainer simpler. Encoding differences in greys is probably a bit more difficult.
The training idea has the merits that once they have learned their plates you can re purpose the pi for other projects
by blimpyway
Tue Sep 03, 2019 7:53 pm
Forum: Automation, sensing and robotics
Topic: Seeking IDEA: Two Cats and Separate Diet Problem
Replies: 5
Views: 158

Re: Seeking IDEA: Two Cats and Separate Diet Problem

I'd train the cats. Hidden camera, 4 buttons: 1 reward 1st plate: drop food menu1 in the plate 2. punish 1st plate: spray some nasty stuff (vinegar? water is ok) instead. Cats hate sprays. 3. reward 2nd plate: drop food menu2 in the plate 4. punish 2nd plate: spray instead Watch cameras. Punish/rewa...
by blimpyway
Sun Sep 01, 2019 10:55 pm
Forum: Automation, sensing and robotics
Topic: Car clutch sensor
Replies: 3
Views: 199

Re: Car clutch sensor

For each gear there-s a fixed ratio between road speed and engine RPM. Anything not closely matching any one of these ratios can be attributed to clutch not being fully engaged. I think (not entirely sure) that both road speed (odometer) and engine rpm are readable with an OBD bluetooth adapter. Tha...
by blimpyway
Sun Sep 01, 2019 10:19 pm
Forum: Python
Topic: Measuring Tx/Rx Range of RF24L01 Using NEO6 GPS Receiver on Raspberry Pi with Python
Replies: 1
Views: 105

Re: Measuring Tx/Rx Range of RF24L01 Using NEO6 GPS Receiver on Raspberry Pi with Python

I tried to follow the video but couldn't spot the point where you got the maximum range... What's the number?
by blimpyway
Sun Sep 01, 2019 10:09 pm
Forum: Python
Topic: picamera long shutter
Replies: 2
Views: 105

Re: picamera long shutter

If you switch cameras on the same Zero one of them works and the other doesn't?
by blimpyway
Sun Sep 01, 2019 10:04 pm
Forum: Python
Topic: Motion sensing code hangs
Replies: 4
Views: 157

Re: Motion sensing code hangs

From the "jpg file is created" I get it is a camera-based motion sensing?

NVM, I'm too tired, its obviously a PIR sensor. What does it has to do with .jpg files?
by blimpyway
Fri Aug 30, 2019 10:23 am
Forum: Automation, sensing and robotics
Topic: HDMI Off Power Saving Reality
Replies: 1
Views: 173

Re: HDMI Off Power Saving Reality

those 20 minutes savings expected at 6 hours of "playing" are realistic only if the PI is doing nothing (idle consumption 350mA) and all other consumers (motors, drivers, servo, camera, sensor etc..) are turned off.
by blimpyway
Fri Aug 30, 2019 9:51 am
Forum: Automation, sensing and robotics
Topic: Motor Sensing Circuit help
Replies: 5
Views: 229

Re: Motor Sensing Circuit help

A way to detect a motor (or any other consumer) is powered or not is to sense its powering switch - being it either a manual switch or a mechanical or solid state relay. Across the switch you get full voltage when opened and zero when closed That can be done with an optocoupler + resistor, and for A...
by blimpyway
Tue Aug 27, 2019 9:15 pm
Forum: Automation, sensing and robotics
Topic: Robot Buggy
Replies: 1
Views: 168

Re: Robot Buggy

Why not using your phone as remote? The Pi may run node-red which you can design "buttons" and "sliders" to do whatever control you need for motors and steering. And show any robot state if you have anything to measure - e.g. currents, rpms, temperatures, etc.. Node-red is a web app, you can interac...
by blimpyway
Tue Aug 27, 2019 9:09 pm
Forum: Automation, sensing and robotics
Topic: Best way to send signal om 2.4Ghz RF
Replies: 6
Views: 262

Re: Best way to send signal om 2.4Ghz RF

A link to, or attaching the pdf of the manual you mentioned. would save a thousand words and "what if-s"

Go to advanced search