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by Ronaldlees
Mon Sep 04, 2017 12:50 pm
Forum: Automation, sensing and robotics
Topic: Using sparkfun photon weather shield with a Pi
Replies: 7
Views: 1577

Re: Using sparkfun photon weather shield with a Pi

I presume you also have the Photon? Anyway, the Photon is fairly versatile. You could run a webserver on the Photon, set it up to display sensor readings via its built-in WiFi, and then just use your Pi to view that webpage. Edit: it looks like the Sparkfun tutorial talks mostly about using either t...
by Ronaldlees
Sat Sep 02, 2017 10:02 pm
Forum: Beginners
Topic: Raspberry Pi wired 150ft connection
Replies: 20
Views: 3207

Re: Raspberry Pi wired 150ft connection

Here's a reference to the 15V max (without GFCI protection): https://www.nachi.org/forum/f19/question-swimming-pool-lights-43751/ Actually, it's a forum that has some "code" quotes. For the other things mentioned, I'll have to dig. Yes, it's a low incidence thing. But, here's the deal. If a person (...
by Ronaldlees
Sat Sep 02, 2017 7:46 pm
Forum: Beginners
Topic: Raspberry Pi wired 150ft connection
Replies: 20
Views: 3207

Re: Raspberry Pi wired 150ft connection

Electrocution is the second highest cause of death for people in swimming pools. Even a battery powered laptop has too high a voltage. Some laptops use 24V batteries, and code calls for only 15V devices near pools. NEAR pools, not IN them. Electrocution in oceanside marinas is common, and in one ca...
by Ronaldlees
Sat Sep 02, 2017 3:39 pm
Forum: Beginners
Topic: Raspberry Pi wired 150ft connection
Replies: 20
Views: 3207

Re: Raspberry Pi wired 150ft connection

Electrocution is the second highest cause of death for people in swimming pools. Even a battery powered laptop has too high a voltage. Some laptops use 24V batteries, and code calls for only 15V devices near pools. NEAR pools, not IN them. Electrocution in oceanside marinas is common, and in one cas...
by Ronaldlees
Sat Sep 02, 2017 3:35 pm
Forum: Beginners
Topic: Raspberry Pi wired 150ft connection
Replies: 20
Views: 3207

Re: Raspberry Pi wired 150ft connection

Is there any connection at all to a mains powered DC supply? Even "through" a computer of some sort? Even through a computer or peripheral, there is danger. There should never be a connection to a wire in water, to any mains connected supply. The reason is simple: the electonics can short-circuit, a...
by Ronaldlees
Thu Aug 31, 2017 4:09 pm
Forum: Automation, sensing and robotics
Topic: GSM vs Bluetooth vs WiFi
Replies: 2
Views: 1336

Re: GSM vs Bluetooth vs WiFi

I've seen some other projects on the forum here, to do what you want to do. In general, I'm against using a complex architecture to do a simple task. For example, my HVAC unit has an 8 bit MCU for control. It hasn't done anything wrong, nor has it reset in 15 years. Cuz it's simple. That said, if yo...
by Ronaldlees
Thu Aug 17, 2017 1:20 pm
Forum: General discussion
Topic: Any point with S.M.A.R.T. capable MicroSD cards?
Replies: 10
Views: 2424

Re: Any point with S.M.A.R.T. capable MicroSD cards?

I have always thought that the smart data caps and the smartmontools were pretty useful. On the hard drives, they give a nice powered-up/hours report, and (IIRC) a temperature report , among other things like sector reports . For the number of uSD cards a typical Pi user would need, the small premiu...
by Ronaldlees
Wed Aug 16, 2017 4:50 pm
Forum: Off topic discussion
Topic: Where to get cheap electronic components?
Replies: 11
Views: 8375

Re: Where to get cheap electronic components?

It depends on what is the purpose of buying electronic components. Actually in USA, the expenses of warehousing, manpower is really high, so the prices of components in USA is not low. For example, if you buy components from Mouser and Digikey, you would find their price is really high. But the adv...
by Ronaldlees
Wed Aug 16, 2017 2:47 pm
Forum: Beginners
Topic: Openwrt
Replies: 14
Views: 4236

Re: Openwrt

Hello: Do you have another Linux machine, so that you can use dd? If so, then try: dd if=openwrt-15.05.1-brcm2708-bcm2709-sdcard-vfat-ext4.img of=/dev/sdd Note that the "sdd" may be something else. ls -lh /dev/sd* Type ls -lh /dev/sd* into a terminal, and the last hot plugged device (probably your u...
by Ronaldlees
Mon Aug 14, 2017 1:28 pm
Forum: General discussion
Topic: Protect SD against going read-only
Replies: 9
Views: 2169

Re: Protect SD against going read-only

Windcheetah wrote:
Mon Aug 14, 2017 12:18 pm
Sorry, no real answer, but mine was from Kingston, and they have just sent me another one!! :D :D :D
Martin
I've had good luck with those (especially their SSDs).
by Ronaldlees
Sat Aug 12, 2017 4:34 pm
Forum: Off topic discussion
Topic: What I do when I'm not playing with my PIs
Replies: 5
Views: 1989

Re: What I do when I'm not playing with my PIs

"Youngsters On The Air" (YOTA ) is an international event which this year was hosted by the Radio Society of Great Britain (RSGB). It was held at the Scouting centre at Gilwell Park and there were youngsters from over 20 countries attending. Last Monday I helped a group set up portable radio statio...
by Ronaldlees
Sat Aug 12, 2017 4:24 pm
Forum: Automation, sensing and robotics
Topic: Powering Robot with 9V Batteries
Replies: 8
Views: 1766

Re: Powering Robot with 9V Batteries

Nine volt batteries do not have a very flat discharge curve. The last half of the battery capacity will be at 8 volts or less, and the last quarter will be at 7 volts or less (thereabouts). I use batteries with a flat discharge curve (I think they have the flattest DC of any battery). They are NiMH ...
by Ronaldlees
Sat Aug 12, 2017 4:09 pm
Forum: Beginners
Topic: Pi V2-Jessie crashed. Can not reformat SD card???
Replies: 7
Views: 1169

Re: Pi V2-Jessie crashed. Can not reformat SD card???

Yes - it's a hardware issue. See: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=190645 The uSD disk's metadata can get trashed if there's an unexpected power shut-off. When the uSD or SD looks at the trashed metadata, it can't figure out a safe write option, and thus does nothing. Hence, i...
by Ronaldlees
Sat Aug 12, 2017 3:55 pm
Forum: General discussion
Topic: Protect SD against going read-only
Replies: 9
Views: 2169

Re: Protect SD against going read-only

I had this issue with SD cards going read-only or just parts of them going read- only a few times back in the early Pi days. Nothing would fix them and nobody offered a suggestion as to why this happened. Apart from the mantra of "Use a good power supply, use good SD cards, "always shutdown cleanly...
by Ronaldlees
Sat Jul 29, 2017 2:31 pm
Forum: Beginners
Topic: Will more current damage my Pi?
Replies: 13
Views: 1848

Re: Will more current damage my Pi?

Maybe the OP has gone already, but I noticed he didn't say which brand supply he is using. I have noticed that some cheaper supplies get quite hot if operated very close to the advertised maximum current level. In fact, one such unit could not be used at much over 50 percent of the advertised curren...
by Ronaldlees
Sat Jul 22, 2017 3:58 pm
Forum: Beginners
Topic: 3 Dead Pi Zero Ws!
Replies: 8
Views: 1499

Re: 3 Dead Pi Zero Ws!

Well, the good news is that you didn't smell any smoke. So, you could have a bad image, or be doing something during the copy of the image that is not transferring it properly, etc. I imagine you've checked all the power supply voltages? The battery and the mains supply? I would make sure that it's ...
by Ronaldlees
Tue Jul 18, 2017 7:41 pm
Forum: Automation, sensing and robotics
Topic: Robot Life on Ni-MH Batteries
Replies: 1
Views: 482

Re: Robot Life on Ni-MH Batteries

Those NiMH bats are a lot tougher than the common wisdom says they are. Glad you got your bots going again.
by Ronaldlees
Tue Jul 18, 2017 12:56 am
Forum: General discussion
Topic: Raspberry with sql
Replies: 3
Views: 619

Re: Raspberry with sql

I found Sqlite3 works pretty well for small projects and it comes with Python. I'm using Sqlite3 on a Pi2 with PHP and Wordpress to serve blog pages. The same Pi also serves as the access point. I read that MySQL would consume more resources on the Pi, and might take something from the blog-server'...
by Ronaldlees
Mon Jul 17, 2017 5:52 pm
Forum: General discussion
Topic: RFID Mid-Range reading (0.5m - 1m)
Replies: 2
Views: 2058

Re: RFID Mid-Range reading (0.5m - 1m)

The descriptions are a little vague about range. Sometimes stated as "one meter, or less" or "up to one meter." I guess that's why you want advice from someone who has a specific device. Of course, there's a dependency on both sides (tag and reader). Hope you don't need the UHF stuff. It's $$$$$$ Yo...
by Ronaldlees
Mon Jul 17, 2017 5:41 pm
Forum: Beginners
Topic: Raspberrypi burned
Replies: 9
Views: 1230

Re: Raspberrypi burned

I imagine the Zero is set up the same way as the Pi2 in terms of the regulator? Or not? Similar. No fuse. No PWR LED. The rest of the power circuit is mostly the same. Thanks for that info. I think I must have put the edit into the message (above) - for the "fuse" - about the same time as you poste...
by Ronaldlees
Mon Jul 17, 2017 5:33 pm
Forum: Beginners
Topic: Raspberrypi burned
Replies: 9
Views: 1230

Re: Raspberrypi burned

Are you sure it's "burned?" What do the LED lights do when you power it up? I had a couple Pi2 boards that looked "dead" - but brought them back to life by powering them thru the 3.3VDC GPIO pin (#1), thus bypassing the dead 5V regulator (using a separate 3.3 VDC supply, of course). That supply need...
by Ronaldlees
Sun Jul 16, 2017 3:36 am
Forum: General discussion
Topic: why is my ethernet cable magnetic?
Replies: 10
Views: 2474

Re: why is my ethernet cable magnetic?

Yes, it's fairly common, where there's a need for strength. It's not just the cheap stuff. A lot of the smaller diameter coaxial cables use steel/copper combos.
by Ronaldlees
Wed Jul 12, 2017 12:28 am
Forum: Automation, sensing and robotics
Topic: Lipo battery leak: is it possible?
Replies: 5
Views: 1383

Re: Lipo battery leak: is it possible?

Looks like a nice project, but if I were you I might be worried about somebody tripping over your sensor control unit. Is it on top of the deck, next to the pool? It seems like it is on top of the tile in the photo ...
by Ronaldlees
Tue Jul 11, 2017 3:23 pm
Forum: General discussion
Topic: https on apache2. https does not work out side home network
Replies: 9
Views: 2586

Re: https on apache2. https does not work out side home netw

Well, when you test inside the home, are you on the same machine as the server?

It sounds like you haven't put the cert on the client you are using when you are outside of the home.
by Ronaldlees
Tue Jul 11, 2017 2:56 pm
Forum: Automation, sensing and robotics
Topic: Lipo battery leak: is it possible?
Replies: 5
Views: 1383

Re: Lipo battery leak: is it possible?

Even NiMH can leak if they get too hot, but I'm not a battery expert. IMO - I would be tempted to separate the battery pack enough so that it could be put where it is shaded and cool. This is a good idea no matter what type of batteries are being used. The cabling would have to be such that nobody t...

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