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by davidcoton
Tue Apr 24, 2018 8:20 am
Forum: General discussion
Topic: Controlling three solenoid valves with 12 mA limit
Replies: 17
Views: 449

Re: Controlling three solenoid valves with 12 mA limit

wh7qq wrote:
Tue Apr 24, 2018 1:15 am
The OP originally posted the spec sheet he got from Farnell's web page, originally from Fairchild/On Semiconductor for an FQP30N06L That spec sheet lists a Vgs of 1.0 to 2.5 volts. That was what I based my comments on.
Indeed. The error was neither yours nor the OP's.
by davidcoton
Mon Apr 23, 2018 10:10 pm
Forum: General discussion
Topic: Raspberry Pi Zero - 4K Possible?
Replies: 12
Views: 355

Re: Raspberry Pi Zero - 4K Possible?

I'm not. Just one advertised price. But we're quite used to £1=$1 for consumer electronics.
Prices include tax.
by davidcoton
Mon Apr 23, 2018 10:06 pm
Forum: Troubleshooting
Topic: Using Etcher to write an image file to MicroSD card
Replies: 4
Views: 114

Re: Using Etcher to write an image file to MicroSD card

Your symptoms point to running a non-compatible OS on a Pi3B+. As FTG says, check your Pi version. If Pi3B, it could be a power problem. More likely you have a Pi3B+, and will have to wait until Parrot OS is released in a compatible version.
by davidcoton
Mon Apr 23, 2018 9:59 pm
Forum: General discussion
Topic: Raspberry Pi Zero - 4K Possible?
Replies: 12
Views: 355

Re: Raspberry Pi Zero - 4K Possible?

Imperf3kt wrote:
Mon Apr 23, 2018 9:55 pm
If I recall correctly, aren't those $20 each?
For a much lower performance, you're paying a almost same price as a Pi3B+
One sample comparison of prices tonight:
Pi3B+ £34.00
Pi0WH £12.80
Less than half.
by davidcoton
Mon Apr 23, 2018 9:54 pm
Forum: General discussion
Topic: Pie AND Swan
Replies: 5
Views: 171

Re: Pie AND Swan

Does the swan like raspberry pi?
Are they compatible?
Thanks for the images, but do you have links to the relevant specs? :lol:
by davidcoton
Mon Apr 23, 2018 9:47 pm
Forum: General discussion
Topic: Raspberry Pi Zero - 4K Possible?
Replies: 12
Views: 355

Re: Raspberry Pi Zero - 4K Possible?

Where do you plan to buy ten Pi0w? Are you aware of the one-per-customer (at $5/$10) limit? To buy in bulk you need to order hundreds to thousands at once or buy from multiple sellers, seriously increasing postal costs. Or buy Pi0WH -- which has the header fitted but is not (AIUI) restricted to one...
by davidcoton
Mon Apr 23, 2018 7:19 pm
Forum: General discussion
Topic: Controlling three solenoid valves with 12 mA limit
Replies: 17
Views: 449

Re: Controlling three solenoid valves with 12 mA limit

Lesson 1. Make sure device and data sheet are from same manufacturer. Not all devices are created equal. :o Lesson 2. Design specs will list a manufacturer, whose component spec has been checked and approved, and whose components have been tested in the particular application. :shock: Lesson 3. Manu...
by davidcoton
Mon Apr 23, 2018 6:58 pm
Forum: Beginners
Topic: Simple question about updating Raspbian after new version released...
Replies: 5
Views: 136

Re: Simple question about updating Raspbian after new version released...

Hi guys. i started my journey with linux when Raspbian was released on 2018-03-13. Now we have 2018-04-18 available. My question is... To get all the functionalities from new image do i have to reflash my SD card and configure everything from scratch? It is possible to upgrade Wheezy to Jessie, and...
by davidcoton
Sun Apr 22, 2018 10:31 pm
Forum: General discussion
Topic: Help needed [with my homework]
Replies: 20
Views: 519

Re: Help needed

According to LibreOffice word count, that's 10001 characters including the DP. Actually it would make no difference if the last digit was dropped (exercise for the reader -- devise the minimum test to prove that).
by davidcoton
Sun Apr 22, 2018 10:52 am
Forum: General discussion
Topic: UPS for a Pi
Replies: 10
Views: 513

Re: UPS for a Pi

@Burngate
You are of course correct with the simple UPS.
But the full proposed system, which has a FET switch in series with D3, does have a problem with R1 bypassing D3/FET. So the battery low switch-off is compromised, as is the ability to restart whern power is restored.

Edit: typos
by davidcoton
Sun Apr 22, 2018 8:15 am
Forum: General discussion
Topic: Question about the SD cards.
Replies: 4
Views: 206

Re: Question about the SD cards.

Just tell Windows not to reformat the card if it asks. There are tools, the current preferred one is "Et ch er", that can write a full system image to an SD card using a Windows system. How you proceed will depend on how you want to install retropi. If you downlaod an image, you can use Etcher to w...
by davidcoton
Sat Apr 21, 2018 8:18 pm
Forum: Beginners
Topic: Problem with connection
Replies: 7
Views: 190

Re: Problem with connection

It's best to allocate a fixed IP address by reservation (and MAC recognition) on the DHCP server. This means there will be no contention, and that you can move your Pi to another network without moving a non-compatible address with it.
by davidcoton
Sat Apr 21, 2018 8:09 pm
Forum: General discussion
Topic: No Wifi connection to Pi Zero W after Raspbian update
Replies: 110
Views: 8369

Re: No Wifi connection to Pi Zero W after Raspbian update

Try adding "scan_ssid=1" in the network section of wpa_supplicant.
by davidcoton
Sat Apr 21, 2018 1:49 pm
Forum: General discussion
Topic: Clear under-voltage flag in vcgencmd get_throttled
Replies: 3
Views: 108

Re: Clear under-voltage flag in vcgencmd get_throttled

Does that work for you? It doesn't seem to have any effect on my Pi2 running up-to-date Raspbian. tim@srv2:~ $ vcgencmd get_throttled throttled=0x50000 tim@srv2:~ $ sudo vcgencmd get_throttled 0x7 throttled=0x0 tim@srv2:~ $ vcgencmd get_throttled throttled=0x50000 Can't say I tried, but AIUI adding...
by davidcoton
Sat Apr 21, 2018 1:37 pm
Forum: Beginners
Topic: Power Supply recommendations wanted
Replies: 7
Views: 216

Re: Power Supply recommendations wanted

pcmanbob wrote:
Sat Apr 21, 2018 1:00 pm
I would defiantly recommend using the official raspberrypi power supply.
Who are you defying? :o
by davidcoton
Sat Apr 21, 2018 1:32 pm
Forum: General discussion
Topic: Heatsink required for Raspberry Pi 3 B+?
Replies: 56
Views: 2306

Re: Heatsink required for Raspberry Pi 3 B+?

maybe the RPF can sell an "official drill" to make "official holes" in the "official case". LOL. But don't use the official drill on the official case with an official Pi in place -- because you could make an unofficial hole that lets out the official magic smoke. And worse, the unofficial replacem...
by davidcoton
Sat Apr 21, 2018 1:23 pm
Forum: General discussion
Topic: Clear under-voltage flag in vcgencmd get_throttled
Replies: 3
Views: 108

Re: Clear under-voltage flag in vcgencmd get_throttled

Bits are cleared on reboot. There is another way, documented later in the same thread.
I'm not aware of any other documentation except the same stuff in other forum threads.
by davidcoton
Sat Apr 21, 2018 9:49 am
Forum: Beginners
Topic: Power Supply recommendations wanted
Replies: 7
Views: 216

Re: Power Supply recommendations wanted

W. H. Heydt wrote:
Sat Apr 21, 2018 12:04 am
Get the "offical" RPF PSU. See: https://www.raspberrypi.org/products/#buy-now-modal
+1
by davidcoton
Sat Apr 21, 2018 9:47 am
Forum: Off topic discussion
Topic: Let's Talk About a Future Simple RasPi!
Replies: 16
Views: 819

Re: Let's Talk About a Future Simple RasPi!

Wow, the good idea from Element14! It has possible removal of RF Module if a nation don't approve this. Pi0W without WiFi and Bluetooth is Pi0. Pi3B without ditto is Pi2B. No radio-less Pi3B+ yet, but since you said BCM2835 was adequate I'm sure a Pi2B wiould do. So where's the gap in the market? A...
by davidcoton
Sat Apr 21, 2018 9:39 am
Forum: General discussion
Topic: Static IP changed on Raspberry Pi
Replies: 4
Views: 169

Re: Static IP changed on Raspberry Pi

The best, easiest way to set a static IP is to reserve the IP in your router's DHCP settings. That way the same device will always get the same IP, without any configuration needed in the OS. Also, the procedure is the same for all devices, instead of having to figure it out for each device and eac...
by davidcoton
Sat Apr 21, 2018 9:34 am
Forum: General discussion
Topic: Remote switch goes from high to low? How to translate that to GPIO function?
Replies: 3
Views: 146

Re: Remote switch goes from high to low? How to translate that to GPIO function?

Your experiments are endangering your Pi. Please stop. You need to understand how the remote works. I can't be certain, but it is likely that the buttons pull a signal down to ground, while a resistor pulls it up to 9V (or whatever). Your Pi may well fail if 9V (or even 5V) reaches its GPIO pins. Yo...
by davidcoton
Fri Apr 20, 2018 6:51 pm
Forum: General discussion
Topic: Heatsink required for Raspberry Pi 3 B+?
Replies: 56
Views: 2306

Re: Heatsink required for Raspberry Pi 3 B+?

rpdom wrote:
Fri Apr 20, 2018 5:34 pm
No, just some official holes in the official case to let the hot air out ;-)
Is the hot air official or unofficial?
Does it make any difference? :lol:
by davidcoton
Thu Apr 19, 2018 10:54 pm
Forum: Troubleshooting
Topic: Issue with custom power supply
Replies: 10
Views: 266

Re: Issue with custom power supply

Is there a way for me to keep voltage enough to power everything ? Use thicker wires? (How long are they?) BTW, 7.5V, even briefly, is dangerously high. Most Pis (1/2/3) have a protection circuit, as long as you use the microUSB for power input. At worst the polyfuse blows, but it should recover ov...
by davidcoton
Thu Apr 19, 2018 9:52 pm
Forum: General discussion
Topic: Raspbian Stretch Headless Setup Procedure
Replies: 62
Views: 94732

Re: Raspbian Stretch Headless Setup Procedure

I'm giving up for now but would love a trick :) Read the first post in theis topic. Stretch WiFi is NOT configured in /etc/network/interfaces, but uses wpa_supplicant instead. This can be prepared and loaded in the same way as the ssh file. (Write both to the boot partition before first boot). Try ...
by davidcoton
Thu Apr 19, 2018 9:41 pm
Forum: General discussion
Topic: Question about program_usb_timeout
Replies: 9
Views: 288

Re: Question about program_usb_timeout

It may be true that I've misunderstood it, but I recall reading that for the new 3B+ model, it is designed to be able to boot via USB - implying there was not a need to set the OTP if you had the 3B+. (still need to for 3B). https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=155167&start=475#p...

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