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by omegaman477
Sat Jun 15, 2019 3:30 pm
Forum: Other projects
Topic: PPG waveform acquistion using Photodiodes - Is it possible with Raspberry Pi?
Replies: 1
Views: 131

Re: PPG waveform acquistion using Photodiodes - Is it possible with Raspberry Pi?

Hey there, I've been trying to make a multi-parameter biomedical system that displays various parameters like SpO2 percentage, Heart rate variability, etc., for which I want to use a red led and a photodiode in order to receive the reflected light from the skin. I would like to know whether this pr...
by omegaman477
Sat Jun 15, 2019 3:24 pm
Forum: Automation, sensing and robotics
Topic: valve to control air flow?
Replies: 6
Views: 203

Re: valve to control air flow?

hi and thank you ;) ok so bit more details about what I'm looking for. I do have an Air compressor with 130litres/min and not so high pressure, this compressor provides air around my outdoor lake. That compressor is connected to two branches, one for one side, second for second side, connected by T...
by omegaman477
Fri Jun 14, 2019 2:32 pm
Forum: Automation, sensing and robotics
Topic: Self-managing race car air suspension
Replies: 7
Views: 395

Re: Self-managing race car air suspension

If you try it in a race, perhaps figure out a way to keep the thing cool and pot the crap out of everything! While potting is a sound method to protect against mechanical shock, moisture and dust. It does not help heat dissipation, in some cases it will work in reverse and make the problem worse. S...
by omegaman477
Fri Jun 14, 2019 2:25 pm
Forum: Automation, sensing and robotics
Topic: Connecting a commercial accelerometer to RaspPi
Replies: 3
Views: 331

Re: Connecting a commercial accelerometer to RaspPi

These type of Laboratory Accelerometers are usually either voice coil or piezo in construction. Both outputting low ANALOGUE DC signals, typically around 1vdc/g. THey send a raw signal, allowing your instrumentation to see peaks curves and spikes. Unlike the chip style accelerometers (usually a Hall...
by omegaman477
Fri Jun 14, 2019 2:09 pm
Forum: Automation, sensing and robotics
Topic: How to maximize Robot Play Time - NiMH Batteries?
Replies: 6
Views: 257

Re: How to maximize Robot Play Time - NiMH Batteries?

BAck to basics. There are only four possible problems here; 1. The charger is not doing its job 2. The battery pack is faulty and not holding a charge 3. The robot is using more power than expected 4. The Juice data is bullshit. I suspect you either have a dodgy charge situation, or a bad cell in th...
by omegaman477
Fri Jun 14, 2019 2:03 pm
Forum: Automation, sensing and robotics
Topic: multiple DS18B20 no longer showing up
Replies: 4
Views: 310

Re: multiple DS18B20 no longer showing up

So your changes broke the circuit. Go back to your last working design Then add the changes one by one. One sensor at a time Guaranteed its a bad connection/crossed wires RJ11 crimp connectors are renowned for trouble. Check all your cables and crimps first. Do not loose sight of the forest for the ...
by omegaman477
Fri Jun 14, 2019 1:56 pm
Forum: Automation, sensing and robotics
Topic: Let's give voice to my robot... Speaker problem
Replies: 11
Views: 516

Re: Let's give voice to my robot... Speaker problem

You dont need a hat for basic sound. So most RPI boards have an Analogue Audio Out via a 3.5mm TRS audio jack, like a PC or Smartphone. Audio needs to be enabled in both firmware and software first, see https://www.raspberrypi.org/documentation/configuration/audio-config.md The Audio out is Line lev...
by omegaman477
Sat Jun 08, 2019 5:22 pm
Forum: Other projects
Topic: Ideas for a Homemade Ware-House System
Replies: 3
Views: 187

Re: Ideas for a Homemade Ware-House System

Hi, i´m very interrested in many thing, not just the RPI only. But i have a real Problem: Many things i own i can´t find because they are somewhere in my Cellar in one of the uncount Boxes. So i have the Idea about a Ware House System like Amazon it use! I´d like to have a Database, where i can des...
by omegaman477
Sat Jun 08, 2019 5:17 pm
Forum: Other projects
Topic: How to internal website send command to terminal raspbian
Replies: 5
Views: 208

Re: How to internal website send command to terminal raspbian

In Python, there are many ways to execute external programs. The easiest one is to import the os package. It provides the popen(), system(), startfile() methods.

But it is dependant on your local O/S.

os.popen() should solve your needs.
by omegaman477
Sat Jun 08, 2019 5:13 pm
Forum: Other projects
Topic: Rpi 4g phone call?
Replies: 4
Views: 209

Re: Rpi 4g phone call?

You do not gain anything from using 4G for voice or SMS - 2G is overkill :lol: PiTalk is a 3G phone http://pitalk.co.uk that you can add your own programs into and the data rate is faster than some ADSL links in the local area :cry: Thats a generalisation. 2G in a lot of countries has been decommis...
by omegaman477
Sat Jun 08, 2019 10:53 am
Forum: Automation, sensing and robotics
Topic: Self-managing race car air suspension
Replies: 7
Views: 395

Re: Self-managing race car air suspension

I want to try and build an "affordable" system that can actively monitor and adjust air pressure in each of the 4 air-shocks using height as the reference measurement. The plan is to use these shocks https://www.airliftperformance.com/product/82607/ and this encoder https://www.adafruit.com/product...
by omegaman477
Sat Jun 08, 2019 10:39 am
Forum: Automation, sensing and robotics
Topic: Raspberry Pi distance measuring
Replies: 4
Views: 395

Re: Raspberry Pi distance measuring

Trying to keep things simple, If the drive train to the push rod is solid and will not slip, I would use a rotary encoder on the stepper motor shaft, or even simpler a closed loop, servo style stepper motor, when you can be sure that no steps are missed. There are many options here available, all fu...
by omegaman477
Sat Jun 08, 2019 10:23 am
Forum: Automation, sensing and robotics
Topic: Turn on/off lights from button/sensor
Replies: 2
Views: 110

Re: Turn on/off lights from button/sensor

I would be looking to use standard Home Automation (HA) light/power/sensor devices around you shop, Phillips Hue, Zigbee, Zwave, iHome, Netamo) They are cheap, easy to install etc. What they all lack is complex condition/decision programming. There are a couple of HA suites for the RPI (see google),...
by omegaman477
Sun Jun 02, 2019 5:18 am
Forum: Other projects
Topic: Running A Metrics Display Board
Replies: 1
Views: 277

Re: Running A Metrics Display Board

So as you rightly said, getting access to the SAP data is your biggest challenge. If the data you need is in SAP BW, and they have a API enabled for that cube, your good. This is a basic restful API over HTTP. Easy to do on a RPI and with Python. If the data is not in a BW cube, then it gets harder....
by omegaman477
Sun Jun 02, 2019 5:00 am
Forum: Automation, sensing and robotics
Topic: What sensor for controlling home temperature?
Replies: 4
Views: 263

Re: What sensor for controlling home temperature?

sharperalison6 wrote:
Fri May 31, 2019 12:06 pm
Hi,

i was interested by using my raspberry pi to control my home temperature, could you please gimme further informations about which sensor should i use ?
Wired or Wireless?
by omegaman477
Sat Jun 01, 2019 11:45 pm
Forum: Automation, sensing and robotics
Topic: DS18B20 resolution
Replies: 14
Views: 648

Re: DS18B20 resolution

0.25ºC resolution suggests you are not reading the full 12 bits.
by omegaman477
Sat Jun 01, 2019 11:42 pm
Forum: Automation, sensing and robotics
Topic: Self-managing race car air suspension
Replies: 7
Views: 395

Re: Self-managing race car air suspension

This is the sort of pressure transducer I would use: https://au.element14.com/honeywell/px3an2bs250paaax/pressure-transducer-250psi-1-8/dp/2532230?st=pressure%20transducer It produces a 0-5VDC voltage proportional to the pressure sensed. You would then need to pass that signal through a AD convertor...
by omegaman477
Mon May 27, 2019 2:37 pm
Forum: Other projects
Topic: aeroplane live feed to ground
Replies: 4
Views: 351

Re: aeroplane live feed to ground

The biggest factor in selecting a communications systems is understanding the amount of data you want to ship. Basic 360*540 10 fps video is a lot different from full 4kHD at 30 or 60fps. Is the received signal for just kick?, or for security or a HQ public broadcast? all have very different require...
by omegaman477
Mon May 27, 2019 2:19 pm
Forum: Automation, sensing and robotics
Topic: Hive Monitoring
Replies: 4
Views: 380

Re: Hive Monitoring

Greetings, Does anyone have recommended solutions or a sensor setup that would work for my project? I want to integrate movement , temperature , humidity , and carbon dioxide , along with a microphone for monitoring sound or sound levels, all onto a Raspberry Pi to capture data from inside my beehi...
by omegaman477
Mon May 27, 2019 2:09 pm
Forum: Automation, sensing and robotics
Topic: [ROS] 8-legged robot
Replies: 1
Views: 204

Re: [ROS] 8-legged robot

I have used this controller extensively in many projects. I have personally had 8 units realtime controlling 128 servos, all real time tracking. It controls any servo on the market. Its bullet proof, flexible and simple to control. Being I2C you can use many of them on one bus. It simplifies the Ser...
by omegaman477
Tue May 21, 2019 7:30 pm
Forum: Automation, sensing and robotics
Topic: Volume Scale
Replies: 3
Views: 345

Re: Volume Scale

To get the millimeter accuracy your require, will be hard with DIY lasers. I would seriously look at MAchine Vision, as this is the way the commercial volumetric scanners are going. You would need two cameras, one looking down to determine width and depth, and one from the back to sense width again ...
by omegaman477
Tue May 21, 2019 7:27 pm
Forum: Automation, sensing and robotics
Topic: Know where I can get reasonably priced DPST/DPDT 240v/8a to 240v/10a relays?
Replies: 16
Views: 916

Re: Know where I can get reasonably priced DPST/DPDT 240v/8a to 240v/10a relays?

This is for high power computer equipment - so not inductive load and pretty constant power draw. 240v - constant pull at 5 to 6 amps depending on the unit. They are a pretty good load. I'll look at them. I'm finding more options in the 24v coil side - beginning to think that using the little JBtec...
by omegaman477
Sun May 19, 2019 5:52 am
Forum: Other projects
Topic: I want to build a peephole cam with Raspberry pi
Replies: 1
Views: 273

Re: I want to build a peephole cam with Raspberry pi

The camera you picked uses analogue or composite video, and that is not something a RPI can interface to out of the box. Look for a similar camera that is USB. That will plug straight in to the RPI. Or you can use a Composite Video encoder hat like https://www.electronicsweekly.com/blogs/gadget-mast...
by omegaman477
Sun May 19, 2019 4:16 am
Forum: HATs and other add-ons
Topic: PoE cable recommendation
Replies: 1
Views: 264

Re: PoE cable recommendation

Basic Cat.6 is fine. Your distances are very short.
by omegaman477
Sun May 19, 2019 4:10 am
Forum: Other projects
Topic: APCUPSD with multiple UPS on Stretch
Replies: 2
Views: 312

Re: APCUPSD with multiple UPS on Stretch

Check your system log files, what is the error(s) apcupsd is logging when it fails.

Feels like a config syntax error.

Invoke apcupsd with -d 9, to enable detailed logging.

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