Go to advanced search

by Z80 Refugee
Fri May 25, 2018 7:08 am
Forum: Beginners
Topic: Raspberry pi 3 b+ with powerbank
Replies: 19
Views: 11022

Re: Raspberry pi 3 b+ with powerbank

You can't predict whether this unit can supply the necessary current without definite specifications. All you know is that this unit has a capacity of 20Ah (ie if it were able to supply 2.5A, it could do so for 8 hours). Here's how it works: if you buy something from a shop, you look at the informat...
by Z80 Refugee
Thu May 24, 2018 8:38 am
Forum: Beginners
Topic: Use an npn transistor to connect a fan?
Replies: 9
Views: 943

Re: Use an npn transistor to connect a fan?

This link has a diagram thanks to pcmanbob https://www.raspberrypi.org/forums/viewtopic.php?t=194621 The problems with drive discussed in that thread are down to the use of a transistor (with limited current amplification) rather than a Darlington (much higher current amplification and therefore no...
by Z80 Refugee
Wed May 23, 2018 7:46 pm
Forum: Automation, sensing and robotics
Topic: [NOOB] Light control - where to start?
Replies: 11
Views: 1227

Re: [NOOB] Light control - where to start?

HashberryPee wrote:
Wed May 23, 2018 9:42 am
It's like those third party tv remote controls which can learn from the original one.
That's the way I'd like to go.
Do let us know how you get on.
by Z80 Refugee
Wed May 23, 2018 9:03 am
Forum: Troubleshooting
Topic: RPi LED driving problems
Replies: 5
Views: 469

Re: RPi LED driving problems

I have a Raspberry Pi Model B+ V1.2. I was trying to do something simple like turning on/off an LED but I notice that the light was very dim. The RPi works fine, turns on, internet works, boots OS, pins that have 3.3 and 5V work as well as the rest of the pins but when I connect and LED w/ 50 ohm r...
by Z80 Refugee
Wed May 23, 2018 8:55 am
Forum: HATs and other add-ons
Topic: 2,8mm wire cable to RPi pins
Replies: 3
Views: 564

Re: 2,8mm wire cable to RPi pins

viewtopic.php?p=526758#p526758
alexeames wrote:
Thu Mar 27, 2014 6:29 pm
Image
by Z80 Refugee
Wed May 23, 2018 8:06 am
Forum: HATs and other add-ons
Topic: 12V fan without additional power supply - summary
Replies: 19
Views: 4271

Re: 12V fan without additional power supply - summary

I completely forgot about a few darlington transistors TIP122 which I have and I hope I can use as an alternative? Please correct me if I am wrong but these transistors have got built in functionality which will work as a flywheel diode? if this is the case, additional part working as a "security g...
by Z80 Refugee
Tue May 22, 2018 8:10 am
Forum: Beginners
Topic: Building a Wheatstone bridge
Replies: 7
Views: 1026

Re: Building a Wheatstone bridge

The advice (as per the posts in the referenced thread) is to use an instrumentation amplifier. The concluding post sounds like the OP Intended to experiment with an op amp rather than an instrumentation amp. An ordinary op amp has too great an offset and drift for this kind of application - you coul...
by Z80 Refugee
Tue May 22, 2018 7:31 am
Forum: Troubleshooting
Topic: I'm not able to connect my Raspberry Pi with SSH
Replies: 6
Views: 1513

Re: I'm not able to connect my Raspberry Pi with SSH

This: Grab the latest Raspbian image from https://www.raspberrypi.org/downloads/raspbian/ Grab the Etcher software from https://etcher.io/ Install Etcher and use it to write the Raspbian image to your SD card. You don't need to extract the image or format the card prior to writing. Just run Etcher, ...
by Z80 Refugee
Tue May 22, 2018 7:05 am
Forum: Graphics, sound and multimedia
Topic: Pi Zero PWM Audio through LM386 amplifier still very soft
Replies: 7
Views: 1596

Re: Pi Zero PWM Audio through LM386 amplifier still very soft

Try turning up the gain on the lm386...... http://www.ti.com/lit/ds/symlink/lm386.pdf That doesn't explain why the Pi Zero appears to be behaving differently from a 3B. Am I missing something? How can I get a decent volume level with this setup? Any help or pointers in the right direction would be ...
by Z80 Refugee
Mon May 21, 2018 9:51 pm
Forum: Beginners
Topic: Using a shared resistor on different LEDS?
Replies: 4
Views: 346

Re: Using a shared resistor on different LEDS?

Hi, im fairly new to GPIO and I've hooked up one resistor to Ground and split the cable up to 12 GPIO inputs. Can that work? Whether it works depends what you are trying to achieve. If you intend to light a combination of LEDs according to the outputs you set on the GPIO, then no (I assume you mean...
by Z80 Refugee
Mon May 21, 2018 9:43 pm
Forum: Beginners
Topic: Building a Wheatstone bridge
Replies: 7
Views: 1026

Re: Building a Wheatstone bridge

bensimmo wrote:
Mon May 21, 2018 7:22 pm
But have a read here
viewtopic.php?t=173854
The concluding post in that thread looks rather like hope over practicality, flying in the face of advice further up. Just throwing any old op amp at a strain bridge won't cut the mustard.
by Z80 Refugee
Mon May 21, 2018 8:48 am
Forum: Graphics programming
Topic: MPEG2 patents expiring
Replies: 34
Views: 15247

Re: MPEG2 patents expiring

What is it about people that they are unwilling for businesses to make an income? How would you get paid if your employer didn't make an income? The choice is simple: if you want what a commercial enterprise has to offer, you pay for it or do without. Trying to find ways to have it for free destroys...
by Z80 Refugee
Mon May 21, 2018 8:07 am
Forum: HATs and other add-ons
Topic: 12V fan without additional power supply - summary
Replies: 19
Views: 4271

Re: 12V fan without additional power supply - summary

Hello, After reading a number of articles, I think I have finally got my head around this subject however as I have pretty much no knowledge about the electronic, I would really appreciate if someone could give me a little bit of reassurance/confirm my thinking is correct. I have followed steps fro...
by Z80 Refugee
Mon May 21, 2018 6:41 am
Forum: Graphics programming
Topic: MPEG2 patents expiring
Replies: 34
Views: 15247

Re: MPEG2 patents expiring

The various remarks above are misleading. Do not confuse patents with the right to licence. Licence fees are paid in return for the permission to use somebody's product - in this case, the MPEG2 software library. That "somebody" is whoever owns the copyright on the software. The fees the Pi Foundati...
by Z80 Refugee
Sun May 20, 2018 9:56 am
Forum: Advanced users
Topic: Pi 3 B+ fries if 3V3 rail is shorted to 5V
Replies: 19
Views: 5069

Re: Pi 3 B+ fries if 3V3 rail is shorted to 5V

Actually, a lot of consumer product safety work is protecting the user against himself. That is what it means to make a product "safe". I.e., it is all fun and games for us crochety types to be snotty on a forum here - about poor, demented users who short pins together getting what they deserve - b...
by Z80 Refugee
Sun May 20, 2018 9:47 am
Forum: Advanced users
Topic: Pi 3 B+ fries if 3V3 rail is shorted to 5V
Replies: 19
Views: 5069

Re: Pi 3 B+ fries if 3V3 rail is shorted to 5V

Following on from this, is there any protection they could have placed on the 3v3 lines, mainly one sat next to the 5v pins. Yes: What could have been done is to have made them pins 1 & 2 with 0V on pins 3 & 4 - that way an accidental short to an adjacent pin would not be fatal What could be done i...
by Z80 Refugee
Sun May 20, 2018 9:34 am
Forum: Advanced users
Topic: Pi 3 B+ fries if 3V3 rail is shorted to 5V
Replies: 19
Views: 5069

Re: Pi 3 B+ fries if 3V3 rail is shorted to 5V

It was just a bloody suggestion to incite talk of ways it could be improved. I know it is the way it is now, flippity flips sake. :-) How could you improve it from what we get now, on the 3B(+) Education is thinking of way to improve it, not just working around it. RPF/T are constantly looking to i...
by Z80 Refugee
Sun May 20, 2018 8:24 am
Forum: Automation, sensing and robotics
Topic: [NOOB] Light control - where to start?
Replies: 11
Views: 1227

Re: [NOOB] Light control - where to start?

I am not a big fan of the open up the remote and press the switches approach. Not because it can't work, more that it potentially breaks the remote and also means you can't also use the remote separately after the hack. That fair enough, and a valid point of view. However, being a hardware man it w...
by Z80 Refugee
Sun May 20, 2018 7:23 am
Forum: Automation, sensing and robotics
Topic: [NOOB] Light control - where to start?
Replies: 11
Views: 1227

Re: [NOOB] Light control - where to start?

The approach I would take is to hack the existing remote control so that the RPi is used to generate keypad inputs. It may be "quick and dirty", but it should produce results. How can I hack the remote? Is there any device to catch and decode the signals? I mean physically hack: disassemble it, and...
by Z80 Refugee
Sun May 20, 2018 7:15 am
Forum: Beginners
Topic: GPIO button connection with pi zero W
Replies: 5
Views: 732

Re: GPIO button connection with pi zero W

A lot more information is needed before any specific advice can be given. What, exactly, is the circuit?
by Z80 Refugee
Sat May 19, 2018 8:11 pm
Forum: Beginners
Topic: GPIO button connection with pi zero W
Replies: 5
Views: 732

Re: GPIO button connection with pi zero W

It depends exactly how you have connected the switch (button). If you are accidentally or deliberately relying on arbitrary circuit characteristics for the resulting input voltage to the GPIO pin to be within specification, or for the voltage to be out of specification but still just about OK to be ...
by Z80 Refugee
Sat May 19, 2018 12:09 pm
Forum: Advanced users
Topic: Pi 3 B+ fries if 3V3 rail is shorted to 5V
Replies: 19
Views: 5069

Re: Pi 3 B+ fries if 3V3 rail is shorted to 5V

Has anyone noticed that Pi 3 B+ fries if 3V3 rail is shorted to 5V. This did not happen in Pi 3 B. Seems to because of the upgrade to MXL7704 integrated regulator chip. You can read more about it here: https://www.raspberrypi.org/blog/pi-power-supply-chip/. Is there a place where this hardware bug ...
by Z80 Refugee
Sat May 19, 2018 8:05 am
Forum: Windows 10 for IoT
Topic: Running DOS Batch Files
Replies: 9
Views: 2030

Re: Running DOS Batch Files

At first glance, it looks like the "process" command takes parameters which specify character string replacements in a file. These things can be accomplished easily in Linux.
by Z80 Refugee
Sat May 19, 2018 8:01 am
Forum: Automation, sensing and robotics
Topic: [NOOB] Light control - where to start?
Replies: 11
Views: 1227

Re: [NOOB] Light control - where to start?

The approach I would take is to hack the existing remote control so that the RPi is used to generate keypad inputs. It may be "quick and dirty", but it should produce results.

Go to advanced search