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by asandford
Wed Apr 18, 2018 9:48 pm
Forum: Beginners
Topic: Sharing sensor data
Replies: 13
Views: 209

Re: Sharing sensor data

This is interesting. I just brought my first i2c device online, it’s the bme680 from Adafruit but I’m using Pimoroni’s library to run it. It is generating so much more data than the dht22 temp/humidity chip and I want to play with it. I believe that STOMP is a similar protocol to MQTT, is that righ...
by asandford
Tue Apr 17, 2018 11:06 pm
Forum: Raspbian
Topic: STRECH and MQTT
Replies: 85
Views: 39787

Re: STRECH and MQTT

sharatkanthi wrote:
Mon Apr 16, 2018 10:40 am
This is because the web socket library is not installed. Try running

Code: Select all

sudo apt-get install libwebsockets-dev
before running

Code: Select all

sudo apt-get install mosquitto
No you don't.
by asandford
Tue Apr 17, 2018 10:54 pm
Forum: General discussion
Topic: My new zero cost backup system (tada!)
Replies: 1
Views: 136

Re: My new zero cost backup system (tada!)

Rsync doesn't backup, it synchronises; if you delete a files by mistake after your rsync script has run, it's lost (depending on the options you specify).

Regardless, rsync isn't a backup solution, there are many free ones available.

Disclaimer: Backup and recovery solution SME for over 20 years.
by asandford
Tue Apr 17, 2018 10:49 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pulling additional power from GPIO (3.3v/68mA)
Replies: 1
Views: 77

Re: Pulling additional power from GPIO (3.3v/68mA)

rich2018 wrote:
Mon Apr 16, 2018 4:48 am
So i'm wondering how I get additional power out of the GPIO port.
You can't, use a transistor, there are many examples of lighting a lamp on the web.
by asandford
Tue Apr 17, 2018 10:39 pm
Forum: Automation, sensing and robotics
Topic: Air flow and pressure sensors.
Replies: 1
Views: 63

Re: Air flow and pressure sensors.

Sounds like homework to me.
by asandford
Tue Apr 17, 2018 10:35 pm
Forum: Add-ons
Topic: Stepper Motor HAT
Replies: 1
Views: 46

Re: Stepper Motor HAT

I am creating a drawing machine using two stepper motors which change the length of the string which holds the pen (often called a polargraph drawing machine). I am running into problems with the stepper hat and library supplied by AdaFruit (https://www.adafruit.com/product/2348) such as not being ...
by asandford
Tue Apr 17, 2018 10:25 pm
Forum: Troubleshooting
Topic: Installing pip RPLCD error
Replies: 2
Views: 56

Re: Installing pip RPLCD error

Did you try Manual Installation You can also install the library manually without pip. Either just copy the scripts to your working directory and import them, or download the repository and run python setup.py install to install it into your Python package directory. Also, it might be worth contacti...
by asandford
Tue Apr 17, 2018 10:03 pm
Forum: Troubleshooting
Topic: RB 3B+ won't boot, only red led
Replies: 2
Views: 89

Re: RB 3B+ won't boot, only red led

It's been said before, but battery chargers are not the same as power supplies.

Get a rock solid 5V 3A power supply, and your Pi will love you (or at least boot).
by asandford
Tue Apr 17, 2018 9:28 pm
Forum: Automation, sensing and robotics
Topic: how to control multiple valves with single GPIO pin?
Replies: 9
Views: 304

Re: how to control multiple valves with single GPIO pin?

You can do that, but then you need USB hubs to split out to lots of boards. I was thinking of using a shared serial bus, 1-wire, DMX, RS422 etc to keep the wiring simple and cheap and have minimal intelligence and power control for small numbers of valves. The LLAP protocol as adapted by CISECO (RI...
by asandford
Sun Apr 15, 2018 11:58 pm
Forum: Raspbian
Topic: How do you run Raspbian Stretch as Root?
Replies: 3
Views: 189

Re: How do you run Raspbian Stretch as Root?

If you think you need to run an application not designed to run as root, as root, you shouldn't be doing it.

The OS gives you plenty of options to enable an application to access resources without resorting to 'god-mode'.
by asandford
Sun Apr 15, 2018 11:46 pm
Forum: Automation, sensing and robotics
Topic: how to control multiple valves with single GPIO pin?
Replies: 9
Views: 304

Re: how to control multiple valves with single GPIO pin?

Thank you so much for everyone. i running out of space in the product that is the reason i can not use 2 raspberry pi or raspberry pi with ardunio. i want use some small chip which can control valves with 1 GPIO pin of raspberry pi. may be something like DeMUX or some other thing . Some sort of ser...
by asandford
Sun Apr 15, 2018 11:24 pm
Forum: General discussion
Topic: STICKY: Introduce yourself!
Replies: 3324
Views: 611305

Re: STICKY: Introduce yourself!

hello im p1 (phi-one = beer in translation) and i bought R pi for use in VR, robotics and some old computer emulation, but after few weeks i found only problems, software or hardware limitations, some of problems looks like undocumented (probably bytecode) so after short time im strongly skeptic, l...
by asandford
Thu Apr 12, 2018 11:18 pm
Forum: General discussion
Topic: Question on username and port for Homebridge
Replies: 1
Views: 81

Re: Question on username and port for Homebridge

Try the Homebridge forum (if there is one)?
by asandford
Thu Apr 12, 2018 10:42 pm
Forum: General discussion
Topic: Is it possible to use cron to handle other cron
Replies: 7
Views: 319

Re: Is it possible to use cron to handle other cron

richlion2 wrote:
Thu Apr 12, 2018 12:09 pm

I don't know anything about MySQL, but is there any scheduler in that kind of database? Normally you get those in MS-SQL and Oracle.
I'm sure further research on your part will answer that question.
by asandford
Thu Apr 12, 2018 10:24 pm
Forum: Beginners
Topic: No 'Manage Pallette' option in Node-RED
Replies: 6
Views: 128

Re: No 'Manage Pallette' option in Node-RED

That group is good to know about certainly. In my opinion, this is the best forum to ask about Node-Red stuff on the Raspberry Pi. People of all levels of knowledge can help out; with the Google group it's more a case of asking the experts. I don't like forums where the default response is "That's ...
by asandford
Thu Apr 12, 2018 12:28 am
Forum: Raspbian
Topic: RASPBIAN STRETCH auto login as root not working
Replies: 17
Views: 3864

Re: RASPBIAN STRETCH auto login as root not working

Ever hear "If you're not part of the solution, you're part of the problem"? Jeez. That's like telling someone they should never root an Android phone. Take the training wheels off, but you might fall down. You might screw it up so bad you have to reinstall, but you probably won't make the same mist...
by asandford
Thu Apr 12, 2018 12:14 am
Forum: C/C++
Topic: Building code to support wheezy
Replies: 19
Views: 348

Re: Building code to support wheezy

Don't think you'll get much help about anything wheezy related; it's pretty much left for dead now.
by asandford
Thu Apr 12, 2018 12:02 am
Forum: Beginners
Topic: OK, dumb question but... how do you save a Node_RED project?
Replies: 3
Views: 77

Re: OK, dumb question but... how do you save a Node_RED project?

Your flows should be automatically saved in the file "flows_<hostname>.json" according to this document: https://nodered.org/docs/configuration Exactly where this file is saved I must confess to not being entirely sure of, also it might depend on how you started node-red in the first place. You can...
by asandford
Wed Apr 11, 2018 11:40 pm
Forum: Beginners
Topic: No 'Manage Pallette' option in Node-RED
Replies: 6
Views: 128

Re: No 'Manage Pallette' option in Node-RED

As already mentioned, just use

Code: Select all

update-nodejs-and-nodered
I'm not really sure why such an old build is bundled as the respositories will never have up-to-date versions, so breaking apt isn't so much of a problem.
by asandford
Wed Apr 11, 2018 10:51 pm
Forum: General discussion
Topic: Is it possible to use cron to handle other cron
Replies: 7
Views: 319

Re: Is it possible to use cron to handle other cron

How can I read the data from the mysql server located in another vm. I searched that mysql may not be able to provide this function. Any ideas? Use database triggers , they do exactly what you want. The database will automatically execute code when tables are updated. A database trigger is procedur...
by asandford
Mon Apr 09, 2018 11:41 pm
Forum: General discussion
Topic: Is it possible to use cron to handle other cron
Replies: 7
Views: 319

Re: Is it possible to use cron to handle other cron

wtshing wrote:
Mon Apr 09, 2018 8:39 pm
Hi guys,

I create a table to store cron data in mysql, is it possible to set a cron to check the change of the table?
As I want to use a cron to update another cron file so that it can modify and run the scheduled tasks based on the records inside the table.

Thanks.
Use triggers.
by asandford
Fri Apr 06, 2018 8:10 pm
Forum: Automation, sensing and robotics
Topic: which metal is best for using electrolysis purpose?
Replies: 3
Views: 194

Re: which metal is best for using electrolysis purpose?

platinum, perhaps titanium; but your question is way off topic for this forum.
by asandford
Fri Apr 06, 2018 8:05 pm
Forum: Automation, sensing and robotics
Topic: Controlling an Arduino with a Raspberry Pi 3 B+
Replies: 1
Views: 134

Re: Controlling an Arduino with a Raspberry Pi 3 B+

short answer: yes

Less short answer: this has been done loads of times and google is your best route
by asandford
Fri Apr 06, 2018 8:00 pm
Forum: Networking and servers
Topic: [SOLVED] Can Pi zero W run MQTT?
Replies: 89
Views: 9930

Re: [SOLVED] Can Pi zero W run MQTT?

I'm sorry, forgive me but I don't understand. The only difference between the two systems was Stretch vs. Jessie. I obtained the mosquitto part from the same source. Yet on the zero I originally got segfaults when installing on stretch. But when I swapped sd card (comprised of Jessie as the OS) fro...
by asandford
Mon Apr 02, 2018 11:00 pm
Forum: General discussion
Topic: Best Practices: Startup with a non privileged user question
Replies: 12
Views: 441

Re: Best Practices: Startup with a non privileged user question

DougieLawson wrote:
Sun Apr 01, 2018 9:34 pm
+1
Sage advice Mr Sandford.
Thank you, we agree at least on some things.

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