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by geoffr
Thu Oct 20, 2016 9:37 am
Forum: Automation, sensing and robotics
Topic: EMI suppression for inductive AC loads
Replies: 7
Views: 1808

Re: EMI suppression for inductive AC loads

Although my commercial sprinkler controller uses triacs, it has a MOV across each one. Its part number is S10K30 and it has a 47V breakdown voltage. They are available from DigiKey . You could try a 0.1uF capacitor across the load, without any series resistor. You do have the DC power to the Pi sep...
by geoffr
Thu Oct 20, 2016 9:31 am
Forum: Automation, sensing and robotics
Topic: EMI suppression for inductive AC loads
Replies: 7
Views: 1808

Re: EMI suppression for inductive AC loads

If I were trying to solve this problem at work I'd probably focus on isolation between the electronics and the loads, rather than trying to silence the solenoids. Solenoids are always going to be noisy; MOVs will help but you'll never get rid of the transients completely. .... My initial tests usin...
by geoffr
Mon Oct 17, 2016 7:38 pm
Forum: Automation, sensing and robotics
Topic: EMI suppression for inductive AC loads
Replies: 7
Views: 1808

Re: EMI suppression for inductive AC loads

Although my commercial sprinkler controller uses triacs, it has a MOV across each one. Its part number is S10K30 and it has a 47V breakdown voltage. They are available from DigiKey . You could try a 0.1uF capacitor across the load, without any series resistor. You do have the DC power to the Pi sep...
by geoffr
Fri Oct 14, 2016 4:12 am
Forum: Automation, sensing and robotics
Topic: EMI suppression for inductive AC loads
Replies: 7
Views: 1808

EMI suppression for inductive AC loads

One of the interesting challenges I am running into with building an irrigation controller is the EMI generated as a result of switching the solenoid valves. There are really two sets of inductive loads in the project: the relays which switch the AC circuits (here I have flyback diodes integrated in...
by geoffr
Sat Sep 10, 2016 10:44 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A different way to mount a Pi Zero
Replies: 1
Views: 806

A different way to mount a Pi Zero

A project I have been working, rather slowly, is an irrigation controller, which uses a Pi Zero as the brains. I am using a MCP23017 GPIO expander for my outputs, with ULN2803A Darlington transistor arrays providing the conversion from 3.3V to 5V (and allowing me to get enough current to drive my re...
by geoffr
Wed Jul 27, 2016 12:31 am
Forum: General discussion
Topic: Powering RPI through PWM PI hat
Replies: 7
Views: 1435

Re: Powering RPI through PWM PI hat

Hi Geoffr, Thanks for the feedback, that's good information. I'm ultimately working towards a pcb that will run a compute module (patiently waiting for CM 3 to come out) so I think that'll need to be incorporated anyways in the end. I'm going to give it ago with the 5V pins. Is there any difference...
by geoffr
Tue Jul 26, 2016 6:40 am
Forum: General discussion
Topic: Powering RPI through PWM PI hat
Replies: 7
Views: 1435

Re: Powering RPI through PWM PI hat

You can provide a Pi power through the 5V pins on the GPIO. What you need to remember is that you are then bypassing the protection on the power supply input of the Pi. That means your Pi becomes a lot easier to fry. It probably would be advisable to consider whether you should include over-voltage ...
by geoffr
Wed Jul 06, 2016 2:43 am
Forum: Other projects
Topic: Soft Power Switch
Replies: 4
Views: 1865

Re: Soft Power Switch

Hello, This has to have been solved before, but I can't find it via google or searching on this board. I want to run a pi off a LiPo battery, but when the pi is off, I don't want it draining the battery. I'm looking for a configuration that allows for the following: 1) when the pi is off, no power ...
by geoffr
Wed Jun 29, 2016 3:13 am
Forum: General discussion
Topic: $9 Wireless Pi computer
Replies: 5
Views: 1289

Re: $9 Wireless Pi computer

Don't think higher voltage would be beneficial, since 5V power is so commonplace nowadays. And unlike the Pi3, the Zero can run off of almost any 5V supply. Mine draws less than 200mA when connected to my wireless network. I think the weakest 5V charger I've seen was 380mA, which came with a Blueto...
by geoffr
Mon Jun 27, 2016 1:51 am
Forum: General discussion
Topic: Controlling light with classic light switch and GPIO
Replies: 8
Views: 2235

Re: Controlling light with classic light switch and GPIO

Thanx, i am an middle and high voltage electrician and 220 V circuit is not a problem, i will do it right. I tought that there is a problem within an relay. Thanx to davidcoton, i thought so, is not a simple way to do two-way circuit. I will look for some other solution. Faramon You could use a SPD...
by geoffr
Thu Jun 23, 2016 3:12 am
Forum: General discussion
Topic: Solenoid valve operation
Replies: 21
Views: 2964

Re: Solenoid valve operation

Hey there, I am wanting to operate a 24v solenoid valve using the raspberry Pi. Can someone give me a suggestion on how to do this? https://www.orbitonline.com/site_files/manuals/Inline%20Sprinkler%20Valve%20Specification.pdf .... Diode across Relay coil to divert Inductive energy From coil winding...
by geoffr
Wed Jun 22, 2016 9:34 am
Forum: General discussion
Topic: Pi Zero for Australia! All those in favour please comment!
Replies: 14
Views: 1740

Re: Pi Zero for Australia! All those in favour please comme

Hi Pi Powers That Be! Please stop excluding the "Land Down Under" from having a ~$5 computer ... Sure we can buy them but then we have to pay a small fortune to have one shipped here, and that's not cool... I don't care how it's done, whether you let E14 make their own, or send a shipment over, jus...
by geoffr
Wed Jun 22, 2016 2:28 am
Forum: General discussion
Topic: Raspberry Pi - which to get
Replies: 10
Views: 1668

Re: Raspberry Pi - which to get

Being someone who uses the B+/B2/B3/A+ and Zero... Go Pi3, one because it covers all bases and make using the GUI and almost using the web bearable. You can reboot quicker when fiddling and not have to worry that the microUSB or camera connectorares going to be damaged over the Zero. <snip> I would...
by geoffr
Mon Jun 20, 2016 1:36 am
Forum: General discussion
Topic: Raspberry Pi Power Usage
Replies: 9
Views: 1549

Re: Raspberry Pi Power Usage

that could be accomplished easily with a pi zero which runs under 200mA without a display and usb plugged in. tho you will need a separate power supply for the actuator. Yeah but Raspberry Pi Zero's are kind of impossible to find, I could get one but it'd be part of a pack with a bunch of cables I ...
by geoffr
Sat Jun 11, 2016 8:22 am
Forum: HATs and other add-ons
Topic: On/off switch - a bit of an oldie, I guess
Replies: 0
Views: 473

On/off switch - a bit of an oldie, I guess

One of the topics that gets raised every so often is that of an on-off switch - something that I have decided is becoming more important to me now that I am using Pis in gadgets (such as an Airplay receiver). Based on a few ideas I have seen elsewhere, I have started on a prototype which uses the de...
by geoffr
Fri Jun 03, 2016 9:16 pm
Forum: Automation, sensing and robotics
Topic: Pi Zero power consumption after shutdown
Replies: 2
Views: 1662

Re: Pi Zero power consumption after shutdown

Tested on a first gen Zero (no camera connector) but I don't think that makes any difference if no camera is connected. Start up Zero with micro hub with LAN interface plugged in (powered from Zero). Settles down to 180mA (idle) Shutdown Zero hub still plugged in goes down to 45mA Hub is drawing ap...
by geoffr
Fri Jun 03, 2016 12:50 pm
Forum: Automation, sensing and robotics
Topic: Pi Zero power consumption after shutdown
Replies: 2
Views: 1662

Pi Zero power consumption after shutdown

I was wondering if anyone has measured the current through a Pi Zero after it has shut down (i.e. power applied but system shut down). I am busy looking at building an on-off switch to control the power supply to the Pi. If I can't get its current draw below that of a Pi after shutdown, then I need ...
by geoffr
Fri Jun 03, 2016 12:31 am
Forum: General discussion
Topic: Power with solar energy
Replies: 17
Views: 20671

Re: Power with solar energy

Hi! I am only a beginner with theis Raspberry PI I have a Raspberre B model. My question is: Can I power my Rasphberr 24/7 with this solar panel and a 5000mAh power bank? http://www.ebay.com/itm/5V-800mA-4W-Solar-Panel-USB-for-Battery-Phone-Charger-Kids-Toy-Gift-/171678224530?hash=item27f8d1d092:g:...
by geoffr
Wed May 25, 2016 9:50 pm
Forum: General discussion
Topic: RTC support
Replies: 6
Views: 1085

Re: RTC support

There was a recent post where someone had put together a service using systemd:

viewtopic.php?f=63&t=147450&p=970370&hi ... ub#p970370

I haven't looked at this one yet, but it certainly looks worth a glance.
by geoffr
Wed May 25, 2016 6:28 am
Forum: General discussion
Topic: More Zeros Wednesday
Replies: 27
Views: 4123

Re: More Zeros Wednesday

I believe that, for the resellers involved, there is huge value in selling Zeros and that value is not just simple margin of profit, or even the ability to sell other items and kit bundles on the back of zero sales. It will be highly effective as an indirect marketing tool and will establish those ...
by geoffr
Wed May 25, 2016 12:49 am
Forum: General discussion
Topic: More Zeros Wednesday
Replies: 27
Views: 4123

Re: More Zeros Wednesday

Makes (sad) sense. Btw, the only reason Mikronauts does not carry & resell Pi products is that I'd lose money on every sale, so I totally understand Adafruits position. Correct on the prices, but... Adafruit is not a direct licnsee for any RPT/RPF products except the Pi Zero. Thus, they aren't cont...
by geoffr
Mon May 23, 2016 10:45 pm
Forum: General discussion
Topic: More Zeros Wednesday
Replies: 27
Views: 4123

Re: More Zeros Wednesday

Pihut just tweeted, more Zeros on Wednesday 9AM. Looks like they are on stream now. https://twitter.com/ThePiHut/status/734813189368651777 That means the next stock will be available before the last lot of deliveries is completed. :lol: I think this will start to break the back of the availability ...
by geoffr
Fri May 20, 2016 10:29 am
Forum: General discussion
Topic: Shipment schedules(update?)
Replies: 22
Views: 3033

Re: Shipment schedules(update?)

I'm still really concerned whether this thing will ever be available in sufficient quantities. I'm sure you'll keep up with single-orders as long as there's a limit of one per person. But I want to order 10, and am waiting for that to be possible. It's hardly worth it to order just one, especially ...
by geoffr
Fri May 20, 2016 12:37 am
Forum: General discussion
Topic: Shipment schedules(update?)
Replies: 22
Views: 3033

Re: Shipment schedules(update?)

The plan is to ship to one US and one UK seller every Monday. We may add small shipments in between those if we have capacity; we're also building stock that isn't being sent out immediately while we're doing that. I was thinking a little about the challenges of Pi Zero availability, when it occurr...
by geoffr
Tue May 17, 2016 11:27 pm
Forum: General discussion
Topic: Pi Zero unit economics
Replies: 30
Views: 3859

Re: Does the Pi Zero have sensible unit economies?

Okay. Followup: do you think anyone else will do something similar, in a similar price range? The closest comparable device is probably the CHIP, which has a RRP of USD 9.00. While it has more functionality, like built in wireless, it has disadvantages like: Currently the CHIP is still in pre-order...

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