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by Tarcas
Sat Mar 28, 2015 1:07 am
Forum: Automation, sensing and robotics
Topic: voicecommand best mic poll
Replies: 2
Views: 549

Re: voicecommand best mic poll

I used an inexpensive webcam with built-in mic. It worked fairly well from about 10-15 feet (3-5 meters) away, but it was positioned directly under a TV, and whenever the TV was on it was completely useless due to the nearby noise.
by Tarcas
Wed Mar 04, 2015 1:45 pm
Forum: Automation, sensing and robotics
Topic: PWM of Pi 2
Replies: 4
Views: 987

Re: PWM of Pi 2

Dougie, I suspect what he means is that due to the fact that the processor is so much faster, can it PWM at higher frequencies? I could be mistaken, but I believe the max frequency of the B+ was CPU-limited, so it's entirely plausible that the v2 has better specs in that regard. A quick google searc...
by Tarcas
Sun Mar 01, 2015 8:17 am
Forum: Automation, sensing and robotics
Topic: Automated Notification with Photocells
Replies: 1
Views: 289

Re: Automated Notification with Photocells

How far do you want to scale? A+ or B+ or v2 will get you 26 GPIO pins. If you want more than that, you'll need to go digital -- something like a chip that adds more GPIO pins, or some sort of sensor array (Can you do something resembling charlieplexing but with sensors? I only skimmed your article,...
by Tarcas
Mon Feb 23, 2015 4:20 am
Forum: Automation, sensing and robotics
Topic: First project advice, app, motor control
Replies: 4
Views: 609

Re: First project advice, app, motor control

To drive a DC motor in two directions you'll want an H-bridge. These can be controlled by a Pi, no problem, as long as you have a separate power source (or the motors are tiny, which in your case they will not be.) Look around and check for one that will handle the amperage that your motors need. If...
by Tarcas
Mon Feb 23, 2015 4:04 am
Forum: Automation, sensing and robotics
Topic: Hall effect sensor question
Replies: 3
Views: 1234

Re: Hall effect sensor question

The hall effect sensors that I have don't pull the signal up to vcc, it's either GND or floating, and you use a pull-up to make floating something predictable. This works very well with the Pi, since I can power the sensor off 5v, and use a pullup on the signal pin to 3.3v so that the GPIO remains s...
by Tarcas
Fri Feb 20, 2015 3:04 pm
Forum: Automation, sensing and robotics
Topic: using Multiple pi's as slaves
Replies: 12
Views: 4773

Re: using Multiple pi's as slaves

hi! i'm working on a home automation project but im pretty new to the rpi world.. i have 1 pi working, where i have some relays connected on, those i can acces by a webpage ( i only have really basic html knowledge) this works all very well (nothing complicated, just some buttons to control the rel...
by Tarcas
Fri Feb 20, 2015 2:55 pm
Forum: Automation, sensing and robotics
Topic: Raspberry pi problems
Replies: 1
Views: 310

Re: Raspberry pi hanging up

I would say 1 and 2 are excellent first guesses. Fortunately they're relatively easy to test. Replace the power supply with a known good one and put the Pi and, if possible the power supply and RFID reader too, in an enclosure (probably with a nightlight bulb) to keep them warmer. Cheap and easy. If...
by Tarcas
Tue Feb 10, 2015 3:01 am
Forum: Automation, sensing and robotics
Topic: Motor Direction Control
Replies: 10
Views: 1821

Re: Motor Direction Control

You could follow any tutorials you find that use an L298N or L293D dual H-Bridge and substitute in your relay board. EXCEPT for the video from TheRaspberryPiGuy on H-bridges. He connects his in a way which has caused Pis to burn out. He connects 4 wires to what he calls the enable pins. Unfortunate...
by Tarcas
Sun Feb 08, 2015 2:56 am
Forum: Automation, sensing and robotics
Topic: How to remotely control devices connected to my raspberry pi
Replies: 11
Views: 1455

Re: How to remotely control devices connected to my raspberr

I've been using this to control my home automation controller through Google Chat from my phone. It would (probably) be child's play to create an app to send a chat message to the house's account with the given command. I intend to do just that in the future, but I haven't yet. Anyway, here's the Pi...
by Tarcas
Sun Feb 08, 2015 2:45 am
Forum: Automation, sensing and robotics
Topic: SMS Communication with Raspberry Pi
Replies: 2
Views: 831

Re: SMS Communication with Raspberry Pi

I don't use SMS, but if XMPP (AKA Jabber, used by Google Chat) is acceptable, check this project out. I've been using it in my home automation project: http://mitchtech.net/raspberry-pi-google-talk-robot/ It acts as a chat bot, and it does let you control GPIO through the chat, among other things. I...
by Tarcas
Sat Jan 31, 2015 1:25 am
Forum: Automation, sensing and robotics
Topic: Emmercy shutdown of devices
Replies: 2
Views: 773

Re: Emmercy shutdown of devices

Sounds fairly easy, if you can get the Pi to do each of those parts. A DHT22 will go from -40 to 80 C, so that fits your specs. Can you send a signal to the UPS to make it shut off? If so, write a script like this (this is pseudocode, so you'll have to translate it to whatever language you want to u...
by Tarcas
Tue Jan 27, 2015 2:47 am
Forum: Automation, sensing and robotics
Topic: Detailed Description of the RHT03 / DHT22 / AM2302 sensors
Replies: 56
Views: 18311

Re: Detailed Description of the RHT03 / DHT22 / AM2302 senso

Hi Tarcas, Maybe you misunderstood? I have (had) three DS18B20's on the 1-Wire bus. They each show-up as a different file, named by using their serial number. The data in those files can be read for the individual readings. I have replaced one by an AM2302, using the method I described, to add the ...
by Tarcas
Mon Jan 26, 2015 6:07 am
Forum: Automation, sensing and robotics
Topic: Detailed Description of the RHT03 / DHT22 / AM2302 sensors
Replies: 56
Views: 18311

Re: Detailed Description of the RHT03 / DHT22 / AM2302 senso

Hi Paul, did you ever try to test the maximum cable length? On the DHT22 datasheet it says that the sensor communication works over a distance of 20m but later on I found this statement: "With 3.3V supply voltage, cable length shall not be greater than 100cm. Otherwise, the line voltage drop will l...
by Tarcas
Mon Jan 26, 2015 6:03 am
Forum: Automation, sensing and robotics
Topic: Detailed Description of the RHT03 / DHT22 / AM2302 sensors
Replies: 56
Views: 18311

Re: Detailed Description of the RHT03 / DHT22 / AM2302 senso

Paul, You mentioned that "All three sensors are on the same 1-Wire bus." I'm wondering how you connected them so that you can poll the temperature from each individually. Any way I can think to do that would trigger all three at once (or none at all, ever) and you'd get a mess when all three respond...
by Tarcas
Sat Jan 24, 2015 2:58 pm
Forum: Automation, sensing and robotics
Topic: Clone SD card
Replies: 3
Views: 703

Re: Clone SD card

Given I only want to clone the SD card running the PiBot using a read write adapter plugged into the Pi Hub I am guessing that I would modify the code as follows: dcfldd if=ImageFileToBeCopied.img of=/dev/sda However, my guess did not work -- any suggestions to allow me to clone the PiBot SD card w...
by Tarcas
Sat Jan 24, 2015 2:43 pm
Forum: Automation, sensing and robotics
Topic: My remote garage door opener
Replies: 70
Views: 66111

Re: My remote garage door opener

Hey, I installed my webcam using the following tutorial- http://jacobsalmela.com/raspberry-pi-webcam-using-mjpg-streamer-over-internet/ But i can access it in the webiopi only from outside the network So i added another stream with the internal ip address which works when i m on the same network So...
by Tarcas
Tue Jan 20, 2015 11:50 pm
Forum: Automation, sensing and robotics
Topic: Use GPIO to short circuit 2 contacts?
Replies: 19
Views: 1724

Re: Use GPIO to short circuit 2 contacts?

You probably want a mechanical relay, preattached to a relay board. You can get cheap ones that will handle up to 220 volts for a couple of dollars, but as others have said, measure the voltage. Don't assume that the 3v supplied is being passed directly to the flash bulb.
by Tarcas
Tue Jan 20, 2015 11:45 pm
Forum: Automation, sensing and robotics
Topic: greenhouse automation
Replies: 10
Views: 1269

Re: greenhouse automation

Hi I would like to make it so at 7am turn on the water for 15 minutes and 5 minutes at night and for the sensors I want them to open the flaps on the greenhouse and humidify the air Thanks Robbie compton Look up cron. It's a scheduler. If you can write a script to do something, you can have cron ru...
by Tarcas
Tue Jan 20, 2015 4:48 am
Forum: Automation, sensing and robotics
Topic: Powering Pi over active POE switch
Replies: 8
Views: 4602

Re: Powering Pi over active POE switch

I'm not a PoE expert, but I am a network engineer and know more than a little about it. 802.3af and 802.3at are the IEEE PoE standards. They specify 48V DC, and do require quite a bit of intelligence on the endpoints. I have seen that there are Pi adapters for these, and they are quite expensive. I...
by Tarcas
Tue Jan 20, 2015 4:27 am
Forum: Automation, sensing and robotics
Topic: Control RF remote with GPIOs, help
Replies: 8
Views: 1183

Re: Control RF remote with GPIOs, help

Thank you guys for all the replys! Anyway I orderd on ebay the same relay board as he is using + some extra stuff that can be usefull, sensors, cables etc. Shipping is around 3 weeks but later I'm going to post some kind of result just in case someone ends up on this thread in the future. Thanks ag...
by Tarcas
Sun Jan 18, 2015 11:40 pm
Forum: Automation, sensing and robotics
Topic: Powering Pi over active POE switch
Replies: 8
Views: 4602

Re: Powering Pi over active POE switch

I'm not a PoE expert, but I am a network engineer and know more than a little about it. 802.3af and 802.3at are the IEEE PoE standards. They specify 48V DC, and do require quite a bit of intelligence on the endpoints. I have seen that there are Pi adapters for these, and they are quite expensive. If...
by Tarcas
Sun Jan 18, 2015 11:21 pm
Forum: Automation, sensing and robotics
Topic: Control RF remote with GPIOs, help
Replies: 8
Views: 1183

Re: Control RF remote with GPIOs, help

Here's the video I was talking about: https://www.youtube.com/watch?v=b6ZagKRnRdM The problem video in question is the one on the H-bridge control board. If you watch his video on that, check the comments (mine included) for that video and plenty of people will tell you the mistake and what NOT to d...
by Tarcas
Fri Jan 16, 2015 1:50 am
Forum: Automation, sensing and robotics
Topic: Control RF remote with GPIOs, help
Replies: 8
Views: 1183

Re: Control RF remote with GPIOs, help

Note 2: Solid state relays only work for AC. They last many times longer and are more expensive, but I'll tell you now that they won't work at all for this project. AC solid state relays only work for AC. DC solid state relays only work for DC. Ah, okay. I guess I've only run into AC ones (or only ...
by Tarcas
Fri Jan 16, 2015 1:49 am
Forum: Automation, sensing and robotics
Topic: 433Mhz RC Outlets known to work with rcswitch-pi
Replies: 6
Views: 2123

Re: 433Mhz RC Outlets known to work with rcswitch-pi

Comparing the data word produced by rcswitch and the remote control there are clearly differences ! If you're able to find the differences, why not update the code to support the outlets you're using? That's the beauty of open source! If you find something that's almost what you need, you can make ...
by Tarcas
Fri Jan 16, 2015 1:44 am
Forum: Automation, sensing and robotics
Topic: Humidity and temp sensors
Replies: 7
Views: 1018

Re: Humidity and temp sensors

Also search this forum for DHT22. Somebody, I think joan, posted some reliable code to read it (They had been very flaky with previous code) and I know there have been a lot of discussions about it, including projects using it. I'm sure you'll find a lot of good info if you're patient. You might als...

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