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by Bope
Sun Sep 22, 2019 8:36 pm
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Re: Leak sensor too sensitive

That makes sense. I have the resistors so it probably is better to put them in now while it is easy versus finding out I need them later when it is hard. Now I get to practice some better soldering techniques.
by Bope
Sun Sep 22, 2019 5:49 pm
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Re: Leak sensor too sensitive

David, thank you fixing my schematic error. My GPIO is connected to the collector not the emitter. I did a test where I left one sensor as it was, another sensor I connected a 1M resistor in parallel, another I connected a 0u1 capacitor and the final one with both the resistor and capacitor. The one...
by Bope
Sun Sep 22, 2019 1:39 pm
Forum: Beginners
Topic: Change Pins RFID-MFRC522 Module
Replies: 2
Views: 59

Re: Change Pins RFID-MFRC522 Module

Your issue is you need to use SPI or I2C to control the module. These pins are fixed on the RPi.
by Bope
Fri Sep 20, 2019 12:06 am
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Re: Leak sensor too sensitive

Is this what your are saying? Can you please explain what the 1M resistor is doing? My understanding is the resistance to the capacitor is lower than that to the transistor so the short spikes would go to the capacitor. Once the spike stopped the capacitor wold just drain to ground. Now when water c...
by Bope
Thu Sep 19, 2019 8:26 pm
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Re: Leak sensor too sensitive

I am not sure where you are thinking to put the 1M resistor. The water acts as about a 0.7M resistor across the sensor. Are you saying I need a resistor in series with the capacitor?
by Bope
Thu Sep 19, 2019 4:20 pm
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Re: Leak sensor too sensitive

The sensor is just 2 metal probes stuck in a piece of plastic about 1.5" apart. The sensor is then connected to the base of a 2N222 transistor. It definitely made the sensor more sensitive to small amounts of water. I did figure it out that the capacitor needs to be on the sensor/base not the emitte...
by Bope
Wed Sep 18, 2019 11:12 pm
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Re: Leak sensor too sensitive

I do have the internal pull up resistors keeping the input from floating.I did a little test and pulled the sensor wire from one input and attached another short piece of wire. I then had the program read the inputs every second. One of the sensors went low 18 times in 2 minutes. The one where I pul...
by Bope
Wed Sep 18, 2019 2:45 pm
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Re: Leak sensor too sensitive

So is the capacitor essentially a low pass filter mopping up the stray noise before it gets to the transistor? Once there is a true signal does the capacitor then fully charge and then allow current to flow to the transistor? I have had a hard time finding 0μ1 capacitors. Is this another way to desi...
by Bope
Tue Sep 17, 2019 11:22 pm
Forum: Beginners
Topic: Leak sensor too sensitive
Replies: 16
Views: 367

Leak sensor too sensitive

So I finally hooked up my water leak sensors and now they are too sensitive. Since my water has relatively low conductivity and I wanted to be able to detect just a little bit of water it was suggested that I use transistors to pull my GPIO pins low. Every thing works fine until I connect the sensor...
by Bope
Tue Sep 17, 2019 1:47 pm
Forum: Beginners
Topic: Soldering
Replies: 22
Views: 607

Re: Soldering

What gauge wire do you like to use to trace circuits? Does the enamel burn off when you are soldering or do you need to burn it off prior to soldering?
by Bope
Mon Sep 16, 2019 11:41 am
Forum: Beginners
Topic: Soldering
Replies: 22
Views: 607

Re: Soldering

Thank you for the information. I like the idea of using the pin cutoffs. I tried making a bridge across two holes but it seemed as soon as I took the iron away the solder wicked back to the holes like the board did not want to be wetted. Those wiring jobs that were posted are pretty impressive. With...
by Bope
Sun Sep 15, 2019 10:03 pm
Forum: Beginners
Topic: Soldering
Replies: 22
Views: 607

Re: Soldering

Let me try to better clarify. I have a perforated board and say I want to solder an LED to the board. I can easily solder the two poles of the LED onto the board. Now I need to attach a pos and ground to the LED. What I did was bend the wires coming through the bottom of the board so they were touch...
by Bope
Sun Sep 15, 2019 8:11 pm
Forum: Beginners
Topic: Soldering
Replies: 22
Views: 607

Soldering

I got the hang of soldering a single wire in the hole in the board. How do you then connect two or more wires that won’t all fit in a single hole in the board?
by Bope
Sun Sep 15, 2019 4:58 pm
Forum: Beginners
Topic: cron vs datetime script
Replies: 2
Views: 78

Re: cron vs datetime script

I was just having the same idea. I added it to my script.
by Bope
Sun Sep 15, 2019 3:26 pm
Forum: Beginners
Topic: cron vs datetime script
Replies: 2
Views: 78

cron vs datetime script

Once I get my leak sensor all hooked up it will be running headless so I want it to send me a message once a month just to let me know it is still running. My understanding is if I use a cron job I could set it up to run a separate python script that will send me out a text message. Does this affect...
by Bope
Sun Sep 15, 2019 1:40 pm
Forum: Beginners
Topic: SMTP mail problem
Replies: 2
Views: 140

Re: SMTP mail problem

Thanks that worked. I had been having problems with this code for awhile and ad read just about every post there is on this subject. There is some discussion out there about port 587 vs 485 and google. I think I had another problem that was causing to not work and that was when I switched to port 48...
by Bope
Sat Sep 14, 2019 11:38 pm
Forum: Beginners
Topic: SMTP mail problem
Replies: 2
Views: 140

SMTP mail problem

I am trying to send and email from a python script and I am getting some errors I don't understand. I am running Stretch so I can use SMTP. Any idea what is going one? Also why is there the smtp.conf file if you are entering the server information, email address and password in the code? Here is my ...
by Bope
Sat Sep 14, 2019 2:49 pm
Forum: Beginners
Topic: Getting strange update
Replies: 4
Views: 259

Re: Getting strange update

I used

Code: Select all

sudo apt-get update
sudo apt-get upgrade
With stretch being end of life I wasn't expecting any updates and then when I saw a bunch of stuff I was a little concerned.
by Bope
Sat Sep 14, 2019 2:23 pm
Forum: Beginners
Topic: Getting strange update
Replies: 4
Views: 259

Getting strange update

I have a raspberry Pi ZeroW running Stretch. I am currently doing an update preparing to install smpt library to send emails. When I ran the apt-get upgrade it is installing a bunch of stuff labeled diversion of /boot/over;ays/.... by rpikernelhack. Then is was installing boot kernel stuff then said...
by Bope
Sun Aug 25, 2019 11:29 pm
Forum: Beginners
Topic: 3.0-3.2V LEDs
Replies: 2
Views: 144

Re: 3.0-3.2V LEDs

Thanks. I thought I might have to drive them with the 5V, just wanted to make sure.
by Bope
Sun Aug 25, 2019 3:59 pm
Forum: Beginners
Topic: Controlling my RBPi in home automation
Replies: 4
Views: 225

Re: Controlling my RBPi in home automation

I have been working on a project where I want my RPi to send a text. What I found is to send a notification. The first one I tried was Pushbullet. Problem with that one is the app on the phone would not indicate a notification until you opened the app. The other one I found was Pushetta. This works ...
by Bope
Sun Aug 25, 2019 2:38 pm
Forum: Beginners
Topic: 3.0-3.2V LEDs
Replies: 2
Views: 144

3.0-3.2V LEDs

I am looking into getting some LEDs for a project. I was thinking of getting a mixture of colors but some of them are listed as 3.0-3.2V and 3.0-3.4V. Can the 3.3V on the RPi drive these or is that too close? I know I can drive the 2.0-2.2V LEDs with a resistor. Just trying to figure out if the high...
by Bope
Sat Aug 17, 2019 2:19 pm
Forum: Beginners
Topic: Leak sensor
Replies: 15
Views: 1689

Re: Leak sensor

Okay if I should go the transistor route what do I buy? One person said 2n2222. I don't know much about choosing transistors. I noticed I can get a boat load of just these transistors or an assortment of transistors for about the same price. Are the assortment packages worth it or should I just get ...
by Bope
Sat Aug 17, 2019 12:40 am
Forum: Beginners
Topic: Leak sensor
Replies: 15
Views: 1689

Re: Leak sensor

Thanks for the help. I gave my system a test and found if I used only a little water it couldn't sink enough to pull the input low. If I used about an inch of water then it could pull the input low. I changed to active high and that would work with just a little water. So I think I will try using th...
by Bope
Fri Aug 16, 2019 8:43 pm
Forum: Beginners
Topic: Leak sensor
Replies: 15
Views: 1689

Re: Leak sensor

That makes meter sense to me that a current limiting resistor should be in place no matter if you are using internal or external Pull Up/Down resistors. I wonder why 42Electronics has us connecting switches directly between ground or 3.3V and an input pin? Is it relatively safe to short either a 3....

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