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by emma1997
Tue Feb 18, 2020 2:44 am
Forum: General discussion
Topic: Powering Pi Zero with AA batteries
Replies: 25
Views: 588

Re: Powering Pi Zero with AA batteries

Yup... that's what I said (google 'BMS' :) ). Of course not relevant here. Diodes also work for dropping volts and definitely better than the usual resistor suggestion. Absolutely easiest and cheapest option however be aware it is most wasteful and could cut run time in half compared to even the wor...
by emma1997
Tue Feb 18, 2020 2:34 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Problem with the Ublox neo 6M gps
Replies: 9
Views: 199

Re: Problem with the Ublox neo 6M gps

1)The Gps led is not blinking at all (I have moved near the window) Window is not good specially with a Pi nearby. Out in the open is better at least starting out. You might find moving the module far away from the Pi helps finding satellites much quicker (or at all). Neo6m is one of my favorites b...
by emma1997
Tue Feb 18, 2020 2:19 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: How to set up GY-NEO6MV2 GPS ?
Replies: 6
Views: 183

Re: How to set up GY-NEO6MV2 GPS ?

Today I tried to conect gps after a half of day i finally to start blinking (red so I hope is good, or red means something is wrong?) Blinking indicates lock and is good. You might find moving the module far away from the Pi helps finding satellites much quicker (or at all). Neo6m is one of my favo...
by emma1997
Tue Feb 18, 2020 1:35 am
Forum: Networking and servers
Topic: Rocket-Ground Communication for Video Streaming
Replies: 2
Views: 72

Re: Rocket-Ground Communication for Video Streaming

I'm model rocketry myself (DIY not Estes etc) but have friends in amateur rocketry and yet even they find long range steaming problematic at that altitude. ESP did not work for them. I don't recall the details but cost may have been a factor. There were lots of licensing issues too because it's ille...
by emma1997
Tue Feb 18, 2020 1:14 am
Forum: General discussion
Topic: Remote power button or reset button?
Replies: 8
Views: 272

Re: Remote power button or reset button?

I ended up crossing RUN and GND with a momentary switch to do what I need. I really needed a hard reset, not a soft reboot, since sometimes it ends up locked. I agree a true reset is needed with the switch-over from good ol' reliable Stretch to flaky Buster. I'm confident they will eventually get m...
by emma1997
Tue Feb 18, 2020 12:40 am
Forum: General discussion
Topic: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.
Replies: 14
Views: 373

Re: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.

Hmmmmmm.... sounds like more of that there anti-social engineering fer sure !!! :) Also, about what for kind of test are you talking? Well you deserve much of the credit inspiring me to do some testing of Pi4 noise vs transistor type. It became quite a subject of discussion at my local radio club. O...
by emma1997
Tue Feb 18, 2020 12:19 am
Forum: General discussion
Topic: Powering Pi Zero with AA batteries
Replies: 25
Views: 588

Re: Powering Pi Zero with AA batteries

I agree with achrn that multiple cells with step down converter is the best way to get the most out of a battery here. Sometimes I use batteries connected directly for simplicity or just for yucks and it works but run time is shorter. For example in recent experiments the same cells arranged for con...
by emma1997
Fri Feb 14, 2020 5:38 pm
Forum: General discussion
Topic: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.
Replies: 14
Views: 373

Re: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.

I think IRL540 is a good safe choice. 10v for IRF840 is only to get max current and since your solenoid only draws a couple hundred ma or so 3v is probably more than enough. IME that part runs cooler than BJT even with 3v drive. TIP120 is also ok if you have one (with low voltage parts and high supp...
by emma1997
Fri Feb 14, 2020 12:24 am
Forum: General discussion
Topic: Stable light in led
Replies: 5
Views: 184

Re: Stable light in led

i am getting very low dimmed light in led Probably the default pullup resistor does that and indicates your 'code' is not working at all. Sometimes I make use of this to get 3 states from the LED: on/off/dim. Surprisingly hard to disable that and actually get tri-state with WiringPi. Seems we must ...
by emma1997
Thu Feb 13, 2020 10:57 pm
Forum: General discussion
Topic: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.
Replies: 14
Views: 373

Re: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.

If the diode is not present the frequency is indeed high and without the diode there is indeed "no" high frequency part. I'm not sure what you meant to say there but we are certainly at least half in agreement. That last half. BTW by 'high' I mean UHF/VHF not low frequency ringing shown in those tr...
by emma1997
Thu Feb 13, 2020 9:53 pm
Forum: Beginners
Topic: Wiring inductive sensors in series
Replies: 38
Views: 693

Re: Wiring inductive sensors in series

You can't put optos in series. Not very many anyway as I explained in my first post. Or any optos at all in this case. Good points Peter. IIRC there was an upper limit to the resistance though. A huge improvement over that first diagram TecHnoGuy. We are definitely headed in the right direction. I f...
by emma1997
Thu Feb 13, 2020 9:42 pm
Forum: General discussion
Topic: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.
Replies: 14
Views: 373

Re: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.

The IRL540N mosfet is Ok ?. And 1K resistor. Yes, IRL540 is one of my favorites because they are so cheap. 100v and 35a at 10 cents is quite a good deal. 1k in series with the gate is also fine and certainly wouldn't hurt. However if you are truly moved by scare tactics a cement block on top would ...
by emma1997
Wed Feb 12, 2020 7:25 pm
Forum: General discussion
Topic: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.
Replies: 14
Views: 373

Re: Which resistor and diode to use ?, for tip120 for 24v solenoid valve.

Most of those tutorials and nearly all internet forum pundits still push circuits and parts from the early 60's. Switching to a modern semiconductor like MOSFET or IGBT can have several benefits. For example no resistors or diodes may be needed at all depending on current and voltages involved. Also...
by emma1997
Wed Feb 12, 2020 6:46 pm
Forum: Beginners
Topic: Wiring inductive sensors in series
Replies: 38
Views: 693

Re: Wiring inductive sensors in series

You really need to follow the link that the OP gave No, I don't 'need' to follow any links at all and would have to be considerably more motivated to do so. If OPs don't bother to attach specs I'm not going to bother hunting them down. You might be right about not understanding details. It's been a...
by emma1997
Wed Feb 12, 2020 6:04 pm
Forum: Beginners
Topic: Wiring inductive sensors in series
Replies: 38
Views: 693

Re: Wiring inductive sensors in series

No interface at all. Specially no opto or relays. Just connect to parallel port on the Pi. A load resistor and maybe divider if outputs are over 4v but mine were not so that was not needed. I did not have time to hunt down specs for your specific part but if they work like industry standard they int...
by emma1997
Wed Feb 12, 2020 12:41 am
Forum: Beginners
Topic: Wiring inductive sensors in series
Replies: 38
Views: 693

Re: Wiring inductive sensors in series

If I'm not mistaken (it did happen one time at band camp, lol) in that diagram the pinouts on those optos are not correct. AFAIK not that many ICs have a pin 0. Numbered and arranged properly input pins 1-2, output pins 4-5. Even wired correctly unlikely to function due to Vsat of optos bipolar tran...
by emma1997
Tue Feb 11, 2020 11:54 pm
Forum: General discussion
Topic: Reasoning behind dual Micro HDMI, and potential future alternatives?
Replies: 125
Views: 9950

Re: Reasoning behind dual Micro HDMI, and potential future alternatives?

lol Jamesh, sometimes it's hard to tell if you are joking or not. It's true some look at it like it's only a couple bucks, others throw a fit over the same difference because it's 300% increase. A wallet is half full or half empty kinda thing I guess. Nah, you get two Micro HDMI to Standard HDMI (A/...
by emma1997
Tue Feb 11, 2020 9:49 pm
Forum: General discussion
Topic: Reasoning behind dual Micro HDMI, and potential future alternatives?
Replies: 125
Views: 9950

Re: Reasoning behind dual Micro HDMI, and potential future alternatives?

I find it odd one of the main issues relating to this has not been mentioned... those small HDMI adapters don't allow for dual display or even powering the Pi. They don't fit. Made much worse by Pi developers decision to use the HDMI closest to the USBC as default. IMO would have been much better to...
by emma1997
Tue Feb 11, 2020 9:27 pm
Forum: General discussion
Topic: Raspberry Pi Broken Usb C connector
Replies: 8
Views: 297

Re: Raspberry Pi Broken Usb C connector

You can power it differently like using poE Not likely. At least not without a setup costing a lot more than the Pi itself. POE pins do not connect to any of the Pi power rails. Powering via GPIO is far more practical. In fact the only way I do it. IMO repairing would not be all that difficult even...
by emma1997
Mon Feb 10, 2020 8:09 pm
Forum: Troubleshooting
Topic: USB 3.0 hubs unreliable on Pi4
Replies: 32
Views: 1618

Re: USB 3.0 hubs unreliable on Pi4

I would be interested to know which 2 chipsets passed. I'm assuming by "passed" you mean "works reliably"? I just opened another known good one to add 12v wires and number on main IC is ASM1153E. Apparently I can now tell which ones will work without cracking open by looking at the cable plug. If i...
by emma1997
Sat Feb 08, 2020 6:43 pm
Forum: Beginners
Topic: Project requiring aux power source
Replies: 10
Views: 296

Re: Project requiring aux power source

You are probably right. Charger with opto or LDR with light definitely safer. Not worth saving 50 cents to risk dealing with 220vac.
by emma1997
Sat Feb 08, 2020 12:09 am
Forum: Beginners
Topic: Project requiring aux power source
Replies: 10
Views: 296

Re: Project requiring aux power source

I'm not sure that's always the case. During a visit to Griffith long time ago there were many small lights around even during observations. I suspect there are some somewhere in there and they don't actually have to be in the same room. Also as rpdom hints and if his UPS are anything like my two the...
by emma1997
Fri Feb 07, 2020 11:16 pm
Forum: Beginners
Topic: Powering a RPi 3B+ through GPIO vs USB
Replies: 14
Views: 360

Re: Powering a RPi 3B+ through GPIO vs USB

These step down switching regulators: serveimage.jpg Input Voltage: 3 to 40 V Output Voltage Range: 1.23 to 37 V Output Current: 3A I am fond of those cheap chinese converters myself but realize are not capable of rated current. 60%-70% at best depending on in/out differential and air flow. Cutting...
by emma1997
Fri Feb 07, 2020 10:39 pm
Forum: Beginners
Topic: Project requiring aux power source
Replies: 10
Views: 296

Re: Project requiring aux power source

As mentioned in other recent threads if there is a room light or an indicator on the UPS then one might consider using an LDR (light dependent resistor). Connects directly to GPIO yet isolated from mains. Lowest cost and fewest parts.
by emma1997
Fri Feb 07, 2020 10:16 pm
Forum: General discussion
Topic: IR Receiver Solution
Replies: 12
Views: 355

Re: IR Receiver Solution

Glad you found those tips useful. The PDF is too big to attach but here's an Ebay link: https://www.ebay.com/itm/10pcs-New-VS1838-TL1838-VS1838B-Universal-IR-Infrared-Receiving-H-CH/392504310515?hash=item5b63147af3:g:PzcAAOSwNphWaO00 They use more than one part number there so a google search is bou...

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