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by mosespi
Tue Jul 17, 2018 5:26 am
Forum: Advanced users
Topic: Controlling the Power Consumption of RPi Models
Replies: 9
Views: 13773

Re: Controlling the Power Consumption of RPi Models

If GeekMike is applying for a US patent, the US Patent Office will grant almost anything that is not blindingly obvious even if prior art exists. They very well might grant one, doesn't mean it is correct. The 'inventor' of the hardware watchdog is likely no longer living. I would take a guess and ...
by mosespi
Sat Jul 14, 2018 8:45 am
Forum: Automation, sensing and robotics
Topic: Switching ON/OFF High Current Load
Replies: 13
Views: 1200

Re: Switching ON/OFF High Current Load

Solenoid type switches/relays sold for starters, golf carts, etc.. are fairly common. They can usually do 100-300A. Fairly low cost.. $10-$30 US around here. Ask for one at a local automotive parts store. You can likely drive it with another relay or a big transistor.

Regards,
-Moses
by mosespi
Fri Jul 13, 2018 2:20 am
Forum: Advanced users
Topic: Solar with RPi Zero v1.3
Replies: 11
Views: 5300

Re: Solar with RPi Zero v1.3

Some thoughts.. Look here for a real world solar example.. http://www.allspectrum.com/mopower/solar/MoPower-UPS-solar.html Convert your calculations in watt and watt hours, makes thing easier when dealing with different voltages, batteries, panels, DC converters, etc. I generally take 3/4 of the rat...
by mosespi
Thu Jul 12, 2018 7:30 pm
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 53
Views: 6181

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

I got tired of waiting on my new battery to arrive, so I just set up a test rig using a regular 2200mAh 18650. (I ended up getting an 18.5Wh LiPo designed for tablets, but it won't be here until August.) While I was at it, I placed a 3A SFE4 fuse inline with the 5v. Note: all (current) testing was ...
by mosespi
Tue Jul 10, 2018 9:54 pm
Forum: Advanced users
Topic: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE
Replies: 7
Views: 994

Re: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE

I opened a github issue. Will see what they say.

https://github.com/raspberrypi/firmware/issues/1017

Thank you everyone for your comments.

Regards,
-Moses
by mosespi
Tue Jul 10, 2018 7:35 am
Forum: Advanced users
Topic: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE
Replies: 7
Views: 994

Re: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE

I tried an upgrade with a previous version above.. but for good measure I've repeated it again.. Clean 2018-06-27-raspbian-stretch was originally.. Linux raspberrypi 4.14.50-v7+ #1122 SMP Tue Jun 19 12:26:26 BST 2018 armv7l GNU/Linux upgraded and became.. Linux raspberrypi 4.14.52-v7+ #1123 SMP Wed ...
by mosespi
Tue Jul 10, 2018 2:16 am
Forum: Advanced users
Topic: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE
Replies: 7
Views: 994

Re: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE

Indeed it looks like some sort of buffer problem. I do use wifi, but this was just an general test, not specifically for my own use. I have a UPS I make and it uses the onboard UART to talk to the Pi. My hardware copes with the issue and retries so it is not a show stopper, but I would like to find ...
by mosespi
Mon Jul 09, 2018 11:48 am
Forum: Advanced users
Topic: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE
Replies: 7
Views: 994

Re: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE

An update: Dropping GPU memory to 8 or 16 MB fixes the problem for the desktop versions, 32 or over and it starts dropping. Lite version does not seem effected, as I cannot get it to drop characters even if I increase GPU memory to 256. What is the difference? Anyone have more insight on what could ...
by mosespi
Mon Jul 09, 2018 7:31 am
Forum: Advanced users
Topic: Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE
Replies: 7
Views: 994

Serial port dropping characters on Raspbian Stretch DESKTOP but not on LITE

Here is a bit of a strange one.. I am having a serial port issue with the Pi. Maybe someone has an idea of what it can be. Using the GPIO serial receiving data, every second or so it seems to lose data for a few milliseconds, it's not corrupt, it's just not there. Like a buffer overflow. No messages...
by mosespi
Tue Jul 03, 2018 12:21 am
Forum: Other projects
Topic: ADS-B Out
Replies: 2
Views: 946

Re: ADS-B Out

I assume you are in the US. ADSB in was fairly easy.. a USB SDR and some software. ADSB out on the other hand is a different animal and requires RF transmission, among other things. There might not be a TSO certification requirement for transponders on experimental aircraft anymore, but I believe it...
by mosespi
Wed Jun 20, 2018 2:57 am
Forum: General discussion
Topic: Power for stacking Pi's
Replies: 21
Views: 3567

Re: Power for stacking Pi's

Did they forget to update the schematic? It still lists the 2.5A part for the 3B+. Not that it makes much of a functional difference, being temperature dependent devices.

Regards,
-Moses
by mosespi
Tue Jun 19, 2018 11:07 pm
Forum: General discussion
Topic: Power for stacking Pi's
Replies: 21
Views: 3567

Re: Power for stacking Pi's

Better, more professional, options are daisy chaining choc-blocks, screw terminals, or blade connector blocks. If using GPIO what power protection circuitry should be added? A 2.5A fuse or polyfuse will return you back to the protection provided by the micro usb input on the Pi. A modern full size ...
by mosespi
Mon Jun 18, 2018 2:54 pm
Forum: General discussion
Topic: Max Amps?
Replies: 10
Views: 4112

Re: Max Amps?

It is industrial type stuff intended to be used in controlled environments or enclosed.. not really intended for the average home user. I wouldn't put one where non-trained fingers could get to it.

Regards,
-Moses
by mosespi
Mon Jun 18, 2018 12:37 pm
Forum: General discussion
Topic: Max Amps?
Replies: 10
Views: 4112

Re: Max Amps?

Abasel, It has a voltage adjustment and the datasheet lists the adjustment range as 4.75v to 5.5v. The combined line, load and 'set up tolerance', which I assume means the adjustment tolerance, is listed at 2% which is pretty good. I would set the output voltage to 5.1v and give it a try, if it meet...
by mosespi
Sat Jun 16, 2018 11:43 pm
Forum: General discussion
Topic: MoPower UPS version 2 in development
Replies: 5
Views: 903

Re: MoPower UPS version 2 in development

Thank you everyone for your comments and support. We are well on our way to production, with first customer shipments scheduled to go out around mid-July. You can pre-order here: http://www.allspectrum.com/store/mopower-ups-v2-designed-for-the-raspberry-pi-preorder-p-9185.html The 5v power section w...
by mosespi
Sat Jun 09, 2018 9:20 pm
Forum: General discussion
Topic: Does the Pi's CE certification include UL94/ISO9772/3 etc?
Replies: 5
Views: 849

Re: Does the Pi's CE certification include UL94/ISO9772/3 etc?

Almost every common modern FR4 PC board I can remember has had some sort of UL94 rating (there are levels). And doesn't UL94 apply to plastic parts only? I'm not an expert in this subject, but I believe it is targeted at plastic parts used on products. I don't know if it would apply to the completed...
by mosespi
Sun Jun 03, 2018 7:28 am
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 53
Views: 6181

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

Looking into this further.. I believe your power/charger board might have the charge current set to 2.5A. Using a 2.5A power supply with a 2.5A charge current might not work well. It must also power your Pi too right? The MP2636 is probably folding back the charge current but likely not before a mom...
by mosespi
Sat Jun 02, 2018 10:49 pm
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 53
Views: 6181

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

I'll throw in my 2 cents. I've always assumed the RPIs official input requirement to follow the USB spec, 5v +-0.25. I do not remember seeing anything official. I have tested several RPi versions at lower voltages and most seem to work all the way down to 3.5v, likely due to the 3.3v regulator. This...
by mosespi
Wed May 23, 2018 4:42 am
Forum: General discussion
Topic: Special-case power requirements
Replies: 11
Views: 1008

Re: Special-case power requirements

Yeah, the 7805 is a poor choice; it's just what I had on hand. I've got a buck converter on order. I also misspoke on the wire gauge; it is 16 AWG, so 40' shouldn't drop more than a tenth of a volt or so. The LEDs are throttled way down with 250 ohm resistors (don't need much output to illuminate 1...
by mosespi
Mon May 14, 2018 1:39 am
Forum: Advanced users
Topic: On/Off switch for RPi 3 B
Replies: 7
Views: 879

Re: On/Off switch for RPi 3 B

Are you sure your source and drain are not swapped? Also, and you may already know this, if you are using a linear regulator make sure to heatsink it properly. If not it may be shutting down due to high temperature. If you are trying for as low idle current as possible you may want to use two regula...
by mosespi
Sun May 06, 2018 8:18 am
Forum: General discussion
Topic: Determine if ceiling fan is moving from 2 or 3 meters away?
Replies: 5
Views: 634

Re: Determine if ceiling fan is moving from 2 or 3 meters away?

I've used one of the IR sensor modules pictured below with good results. Search for "IR module". It's one of these generic modules and should be available from your favorite electronics supplier or China. I ran it from the RPIs GPIO.. so at least some (all?) of them work with 3.3v. I do remember it ...
by mosespi
Sun May 06, 2018 1:10 am
Forum: General discussion
Topic: PIR Sensor
Replies: 5
Views: 514

Re: PIR Sensor

I don't think it refers to a specific PIR sensor given the fact that there is this sentence.. "On some PIR sensors, the pins are clearly labelled on the circuit board. Others have the labels hidden beneath their cap. If this is the case for your sensor, gently pop its cap off so that you can disting...
by mosespi
Sun May 06, 2018 12:47 am
Forum: General discussion
Topic: UPS for a 3B & WD PiDrive Foundation Edition
Replies: 14
Views: 1477

Re: UPS for a 3B & WD PiDrive Foundation Edition

I don't know whether the USB data part of the cable is connected to the USB power. I suppose I could try connecting data only and then power to the pi to see if that worked. If it was that easy I don't think they would have produced this complicated cable in the first place! For a long while the US...
by mosespi
Sat May 05, 2018 5:18 am
Forum: General discussion
Topic: Cryogenic Raspberry Pi & Camera CERN schematic
Replies: 15
Views: 1829

Re: Cryogenic Raspberry Pi & Camera CERN schematic

Physical cracking of the components will likely result at that low a temperature. Most of the parts on the Pi (and all electronics really).. those Integrated circuits, CPU, memory chips.. are all made out of dissimilar materials; plastic, metal, bonding wires, silicon. All expand and contract at dif...
by mosespi
Fri May 04, 2018 4:04 am
Forum: General discussion
Topic: Printing to an RS232 using a USB cable
Replies: 17
Views: 1419

Re: Printing to an RS232 using a USB cable

This might work: plinth666/epsonsimplecups: A simple CUPS driver for the Epson TM-T20 POS printer It should just speak ESC-POS, which is not too complex I worked on similar printers from Eltron/Zebra. They had their equivalent printer 'codes' called EPL and ZPL. It was fairly simple to send basic t...

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