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by paulv
Mon Aug 22, 2016 2:13 pm
Forum: Advanced users
Topic: Characterizing GPIO input pins
Replies: 44
Views: 17418

Re: Characterizing GPIO input pins

Well, it seems you're between a rock and a hard place. If you've followed my post, then you know about the two major issues with RPi.GPIO. There is little you can do about the "OS" glitches, but they don't happen that often. You can avoid the double edge-triggering on the falling edge triggering in ...
by paulv
Mon Aug 22, 2016 7:41 am
Forum: Advanced users
Topic: Characterizing GPIO input pins
Replies: 44
Views: 17418

Re: Characterizing GPIO input pins

Sorry, the way the ISR is written, to avoid the mishaps and issues with the RPi.GPIO code, you have to copy it for every button.
by paulv
Sat Aug 20, 2016 8:13 am
Forum: Advanced users
Topic: Characterizing GPIO input pins
Replies: 44
Views: 17418

Re: Characterizing GPIO input pins

Hi momoaux, Unfortunately, I cannot figure out what it is you need help with. In essence, you need two separate versions of the interrupt service routines (ISR) that check the button presses (one for A and one for B), and use a "main" piece to test for the relationship between them. One way of doing...
by paulv
Mon Jul 25, 2016 7:35 pm
Forum: Beginners
Topic: HOW-TO Start/Stop/Powerdown Pi with 1 Button
Replies: 30
Views: 22630

Re: HOW-TO Start/Stop/Powerdown Pi with 1 Button

Hi belese, Using a voltage divider instead of a zener is fine. (look at the next diagram in the post where I did the same) From this, I assume that you use the first diagram of this post. The fact that the RPi reboots automatically after the powerdown has been requested is not a function of my hardw...
by paulv
Thu Jul 14, 2016 9:11 am
Forum: Device Tree
Topic: poweroff no longer works on GPIO-28-31? [SOLVED]
Replies: 5
Views: 1702

Re: poweroff no longer works on GPIO-28-31? [SOLVED]

Oh Phil, I caused you to waist needless efforts in trying to solve my problem. I investigated the issue on my Model A this morning and tried to replicate it on my B's. They work fine. Turns out, I have a defective Model A. Ports 28 and 29 are shorted to ground. I never, ever assumed this would be th...
by paulv
Wed Jul 13, 2016 6:32 pm
Forum: Device Tree
Topic: poweroff no longer works on GPIO-28-31? [SOLVED]
Replies: 5
Views: 1702

Re: poweroff no longer works on GPIO-28-31?

Hi Phil, There is no such statement anywhere. This is the config.txt file I use to move between my Models (1) A and B, and the Models 2B and 3B. Up until a few weeks ago, this worked. Today, these ports do no longer (seem to?) work. It seems they are pulled to ground really hard, not with the 50K in...
by paulv
Wed Jul 13, 2016 11:59 am
Forum: Device Tree
Topic: poweroff no longer works on GPIO-28-31? [SOLVED]
Replies: 5
Views: 1702

poweroff no longer works on GPIO-28-31? [SOLVED]

[UPDATE] It turns out that GPIO port 28 and 29 on P5 are shorted to ground (3 Ohm and 5 Ohm) on my Model 1 A. Ports 30 and 31 work fine. I have never used these 4 ports, and never noticed any strange behavior on the others on P1. I see no evidence of an issue on the PCB with a strong magnifying glas...
by paulv
Wed Jul 13, 2016 8:15 am
Forum: Advanced users
Topic: using the SCT-013 with the pi via the MCP3008
Replies: 6
Views: 7592

Re: using the SCT-013 with the pi via the MCP3008

I have written a detailed post connecting an SPI A2D convertor (MCP3002) to the RPi, that should give you enough hints to convert to the MCP3008 (which really is overkill for this application). See if this helps to get you on your way: https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=123962 E...
by paulv
Tue Jul 12, 2016 7:35 pm
Forum: HATs and other add-ons
Topic: Pi Power Controller Project (safe reboot anytime)
Replies: 5
Views: 1990

Re: Pi Power Controller Project (safe reboot anytime)

Have a look here : viewtopic.php?f=37&t=145954&p

Or here, depending on your application : viewtopic.php?f=37&t=150358&p

Enjoy!
by paulv
Sun Jul 10, 2016 8:05 pm
Forum: Other projects
Topic: Soft Power Switch
Replies: 4
Views: 1747

Re: Soft Power Switch

Have a look at this post or the references to other ones in it. It may do what you want viewtopic.php?f=37&t=145954

Success
by paulv
Sun Jul 10, 2016 7:39 pm
Forum: Automation, sensing and robotics
Topic: Ultimate rotary encoder switch decoder
Replies: 18
Views: 24599

Re: Ultimate rotary encoder switch decoder

I did one design a while a go too. I think mine is even more simple.
viewtopic.php?f=37&t=126753&p

Enjoy!
by paulv
Sun Jul 10, 2016 7:25 pm
Forum: HATs and other add-ons
Topic: Mausberry 2A Car Switch - Cutting Power Unexpectedly
Replies: 3
Views: 2574

Re: Mausberry 2A Car Switch - Cutting Power Unexpectedly

I think that what you want is described in this post, if not, it will should give you enough information to work from : viewtopic.php?f=91&t=129357

Success!
by paulv
Sun Jul 10, 2016 7:18 pm
Forum: Other projects
Topic: Charging Li-ion cells
Replies: 2
Views: 958

Re: Charging Li-ion cells

Use the search function of the forum and look for "powerboost" to find posts that will point you to information relative to what you want to do.

Be careful with li-ion cells, if you do not charge them correctly, they have a nasty way of letting you know.
by paulv
Sun Jul 10, 2016 7:08 pm
Forum: Beginners
Topic: Powerboost 1000, lipo charger, and usb power
Replies: 5
Views: 1655

Re: Powerboost 1000, lipo charger, and usb power

If you would have used the search feature in the upper right hand corner of this screen, (search for powerboost) you would have found several posts dealing with the Powerboost and the RPi. As a mimimum, it would have given you more information. Have a look here for a complete solution that may give ...
by paulv
Tue Jun 28, 2016 8:44 am
Forum: Advanced users
Topic: Controlling the Power Consumption of RPi Models
Replies: 8
Views: 11279

Re: Controlling the Power Consumption of RPi Models

Hi bensimmo, Yes, you can turn off the HDMI plug. sudo /opt/vc/bin/tvservice –o (or –p to turn it back on) However that saves less than 10mA, but that may depend on the monitor and keyboard that is connected. I measured the power requirements of my Dell monitor (1703FPs) connected to the HDMI interf...
by paulv
Tue Jun 28, 2016 7:23 am
Forum: Automation, sensing and robotics
Topic: Raspberry Pi UPS with Auto Restart
Replies: 20
Views: 13068

Re: Raspberry Pi UPS with Auto Restart

A rather shameless plug for a "product" that claims something new? Look at this earlier post for a power supply that already uses a hardware watchdog : https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=50470&start=25 This was posted in August 2013. I came up with this part of the design myself...
by paulv
Tue Jun 28, 2016 6:35 am
Forum: Advanced users
Topic: Controlling the Power Consumption of RPi Models
Replies: 8
Views: 11279

Re: Controlling the Power Consumption of RPi Models

GeekMike, Thank you for the plug to your product, but the link in my post already describes such a system for the DIY inclined forum users, and it is free of any patent issues. In case you overlooked it, you can also use the "on-board" watchdog the SOC on the RPi, and in combination with the supply ...
by paulv
Mon Jun 27, 2016 9:46 am
Forum: Troubleshooting
Topic: Scaling Governor not working on Model 1 A/B A+/B+?
Replies: 0
Views: 276

Scaling Governor not working on Model 1 A/B A+/B+?

I have been working on another post to shed some more light on the power savings that can be obtained to wedge a Model 2B or 3B into a restricted power budget. Here is that post for information : https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=152692 I also wanted to do some analysis on my M...
by paulv
Sun Jun 26, 2016 12:51 pm
Forum: Advanced users
Topic: Controlling the Power Consumption of RPi Models
Replies: 8
Views: 11279

Controlling the Power Consumption of RPi Models

When you need to run your RPi Model 2 or 3 on a battery or a cell for a period of time, the power consumption becomes an important element. The same is true if you don’t have a wall wart that can supply the energy needed for your RPi. (when you get the dreaded rainbow box on your display) With the a...
by paulv
Tue Jun 21, 2016 4:32 am
Forum: Automation, sensing and robotics
Topic: Raspberry Pi UPS with Auto Restart
Replies: 20
Views: 13068

Re: Raspberry Pi UPS with Auto Restart

Hey Medicdude, Thank you for posting what seems like a warning. Unfortunately I do not fully comprehend what you are trying to convey. For the sake of the readers of this post and myself, can you please substantiate (point to an article or reference) or otherwise explain why you think it is in-appro...
by paulv
Fri Jun 17, 2016 7:14 am
Forum: Automation, sensing and robotics
Topic: Raspberry Pi UPS with Auto Restart
Replies: 20
Views: 13068

Re: Raspberry Pi UPS with Auto Restart

Hi Gordon(77),

Heat yes, but no smoke. (;-))
The Powerboost is well protected against overheating and even a short.
The cells I use have built-in protection against over- and under-voltage and a short as well.
I'm still "green" using Li-ion and Li-poly cells, but I think I'm safe...

Cheers!
by paulv
Thu Jun 16, 2016 6:00 pm
Forum: Automation, sensing and robotics
Topic: Raspberry Pi UPS with Auto Restart
Replies: 20
Views: 13068

Re: Raspberry Pi UPS with Auto Restart

Here is a graph of the efficiency of the Powerboost conversion from cell energy (I*V) to output energy(I*V) with increasing load:
18650 efficiency.gif
18650 efficiency.gif (7.15 KiB) Viewed 12337 times
!Enjoy
by paulv
Thu Jun 16, 2016 3:09 pm
Forum: Automation, sensing and robotics
Topic: Raspberry Pi UPS with Auto Restart
Replies: 20
Views: 13068

Re: Raspberry Pi UPS with Auto Restart

And I have some more information, actually some more bad news for power hungry RPi's... I wanted to measure how well the cell can support the Powerboost output at various current levels, to test the UPS functionality. In this case, there is no power supplied to the main input of the Powerboost. To m...
by paulv
Thu Jun 16, 2016 12:58 pm
Forum: Automation, sensing and robotics
Topic: Raspberry Pi UPS with Auto Restart
Replies: 20
Views: 13068

Re: Raspberry Pi UPS with Auto Restart

Here are some more details of my actual measurements of the Powerboost package. I already measured that the maximum current the Powerboost can supply to the RPi payload is 1.0Amps continuously, and that the cell is used to temporarily boost that current to 1.2Amps. To make the following analysis, I ...
by paulv
Thu Jun 16, 2016 6:00 am
Forum: Automation, sensing and robotics
Topic: RPi Power Supply w. UPS, one button control
Replies: 10
Views: 9667

Re: RPi Power Supply w. UPS, one button control

redm0nk,

Have a look here for a complete (embedded) solution where an RPi is at a remote location using a Powerboost:
viewtopic.php?f=37&t=150358

Enjoy!

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