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by LateDev
Wed Nov 20, 2019 1:42 pm
Forum: C/C++
Topic: Compiling gcc Options
Replies: 36
Views: 13548

Re: Compiling gcc Options

As I said the need for a cross compiler becomes handy when you are writing a large amount of code and want to compile it quickly. The raspberry pi is slow to compile. Plus there is the fact I have 1 monitor 1 mouse and 1 keyboard and even if I doubled this up, then I wouldn't have the space to use i...
by LateDev
Tue Nov 19, 2019 1:39 pm
Forum: C/C++
Topic: Compiling gcc Options
Replies: 36
Views: 13548

Re: Compiling gcc Options

You have a Pi. You can develop on the Pi out of the box. That saves all the pain of cross-compiling. Which is, as you see, I really bad pain if you have to build the cross-compiler first. If you are using a Pi zero with minimalist install, then it won't have a compiler, because it just takes up nee...
by LateDev
Thu Nov 14, 2019 12:14 pm
Forum: Troubleshooting
Topic: USB wifi dongle 0bda:c811 issue: no interface is created, although module is loaded
Replies: 5
Views: 11422

Re: USB wifi dongle 0bda:c811 issue: no interface is created, although module is loaded

I am unsure how to proceed, never having used github for anything. I am on a fast learning curve here, but with very little information to go on I am blind. How do you get the driver in the first place ? I have a pi 2 with only a wifi dongle, no ethernet to connect to. The dongle reports on a PC tha...
by LateDev
Fri Feb 27, 2015 2:00 pm
Forum: Troubleshooting
Topic: B+ Broken MicroSD reader
Replies: 124
Views: 41621

Re: B+ Broken MicroSD reader

Strangely enough I have purchased the Pi 2 and within a week the SD card slot has packed in.
Exactly the same problem, it will not latch.
by LateDev
Tue Feb 04, 2014 8:37 pm
Forum: Beginners
Topic: Battery packs
Replies: 5
Views: 1209

Re: Battery packs

Batteries vary in Voltage, depending on what they are made from. Standard alkaline will be 1.5V each, and the majority of rechargeable will be 1.2V, an exception to this is the Zinc which are again 1.5V This gives you a Voltage range of between 4.8V and 6V. You can of course use a Voltage regulator ...
by LateDev
Tue Feb 04, 2014 8:08 pm
Forum: Beginners
Topic: Tilt sensor-Transistor breadboard implementation.
Replies: 23
Views: 5189

Re: Tilt sensor-Transistor breadboard implementation.

I think you are not quite getting it right. 1) The diode needs a resistor calculated from the forward current of the diode IF of 50mA at the Voltage you are using, 3V3 minus the forward voltage of the diode. roughly 100 R between the Anode(pin 1) and the positive supply 3V3, Pin 2 being connected to...
by LateDev
Mon Jan 20, 2014 6:35 pm
Forum: Beginners
Topic: How to test my IR LED
Replies: 5
Views: 1750

Re: How to test my IR LED

The question was is there a way to test a transistor to figure out what i have to work with? Rather than try to explain how to determine which is base collector and emmitter through testing, I will just give a link to a decent site that explains this in a more simplified way. http://www.allaboutcirc...
by LateDev
Mon Jan 20, 2014 7:07 am
Forum: Beginners
Topic: How to test my IR LED
Replies: 5
Views: 1750

Re: How to test my IR LED

The only sure fire way is to read the letter/number combination and then do a search. Try using Towers transistor guide or similar net search. The problem with using old devices is that you don't know what they are a lot of the time, is it a bipolar transistor or a FET ? both can look physically ver...
by LateDev
Mon Jan 20, 2014 6:54 am
Forum: Beginners
Topic: Rpi and a 256 ch I/O card
Replies: 11
Views: 2394

Re: Rpi and a 256 ch I/O card

Pretty much all the information needed is in those PDF files, just takes some digging around. :) Since the info states quite clearly that the device can be used through hyper terminal with the serial port settings of 115200 bps 8 bit no parity and 1 stop bit, then you should be able to write a small...
by LateDev
Thu Jan 02, 2014 1:37 am
Forum: Beginners
Topic: Stuck: Need switch controled by GPIO
Replies: 30
Views: 4748

Re: Stuck: Need switch controled by GPIO

I guess I don't understand how a MOSFET works then. I originally had a circuit with a switch. I replaced that switch with a MOSFET. The MOSFET states it can handle: VDSS = 55V, ID = 49 A. If I have any circuit that is within those maximums, why can't I just throw the MOSFET in place of a switch. An...
by LateDev
Thu Jan 02, 2014 1:18 am
Forum: Beginners
Topic: PWM Voltage Problem
Replies: 10
Views: 6800

Re: PWM Voltage Problem

Hi, I am trying to drive a dc motor using pwm to set the speed / direction, The dc motor has a pre configured pwm input that I believe is 5v, However i believe the pi pwm output is 3.3v? Thanks As requested post the motor specs. Also don't just go by the Voltage; if it is a TTL input to the motor, ...
by LateDev
Tue Dec 31, 2013 6:29 pm
Forum: Beginners
Topic: Stuck: Need switch controled by GPIO
Replies: 30
Views: 4748

Re: Stuck: Need switch controled by GPIO

Bad thinking on your part I am afraid, everyone here has been discussing LED's as the load and it should not be stressed too lightly that you cannot just replace the LED's with a different type of load.

As far as the FET you specified, the VGS(th) Gate Threshold Voltage is 2.0 ––– 4.0 V.
by LateDev
Tue Dec 31, 2013 3:24 am
Forum: Beginners
Topic: Stuck: Need switch controled by GPIO
Replies: 30
Views: 4748

Re: Stuck: Need switch controled by GPIO

Thanks for everyone's help. I finally figured out what was wrong with the last diagram (beside R2 being on the wrong side of the Gate). When I was reading about MOSFETs, it only speaks of needing voltage at the Gate, and never mentions about current. I figured instead of wasting unneeded current, I...
by LateDev
Tue Dec 31, 2013 3:01 am
Forum: Beginners
Topic: Stuck: Need switch controled by GPIO
Replies: 30
Views: 4748

Re: Stuck: Need switch controled by GPIO

Actually no, you have forgotten VCE the Voltage drop across the drive transistor. If you allow 1V it will be all right for that transistor. ...If we allow VCE of the drive transistor = 1V ... Why? If it's got 1V across it, and 200mA (its maximum) through it, that's 200mW wasted. If it's fully satur...
by LateDev
Sat Dec 28, 2013 4:12 pm
Forum: Beginners
Topic: malware listed from win32 download exc
Replies: 8
Views: 1293

Re: malware listed from win32 download exc

I run malware bytes and it shows no malware on any of my download folders, which must mean you either have a corrupt or infected file.
by LateDev
Sat Dec 28, 2013 3:37 pm
Forum: Beginners
Topic: Stuck: Need switch controled by GPIO
Replies: 30
Views: 4748

Re: Stuck: Need switch controled by GPIO

According to Farnell's data sheet, forward voltage is 1.2v typical, so each string will be 6v leaving 3v for the resistors - 64mA (which is actually above the 50mA absolute maximum, but hey, who's counting? And the 9v battery will soon lose some volts, anyway) When I run the circuit above, a string...
by LateDev
Sat Dec 28, 2013 1:35 pm
Forum: Beginners
Topic: installing os
Replies: 9
Views: 1436

Re: installing os

Hi, Thanks for your response. We have tried both holding the shift key and toggling; we have tried 2 keyboards that both work. feeling really frustrated now as we have spent hours on internet searching how to change os and all info says return to first menu! Some of the sites even suggest changing ...
by LateDev
Thu Dec 26, 2013 4:30 pm
Forum: Advanced users
Topic: Some trouble with a Relay
Replies: 21
Views: 21107

Re: Some trouble with a Relay

Just so that you remember, you are dealing with an inductive load, more akin to a motor than a resistance. So you have start up current for the relay, then a lower holding current, the resistive calculation only being a very rough evaluation, so an allowance should be added in. You also have to take...
by LateDev
Thu Dec 26, 2013 4:21 pm
Forum: Beginners
Topic: Stuck: Need switch controled by GPIO
Replies: 30
Views: 4748

Re: Stuck: Need switch controled by GPIO

Burngate is correct, as you can sink more current with the Pi, than source. PSU on board is limited to 50mA
by LateDev
Thu Dec 26, 2013 1:52 pm
Forum: Troubleshooting
Topic: Car stereo - Raspbmc question
Replies: 9
Views: 2048

Re: Car stereo - Raspbmc question

Ok, so my apologies for the inaccurate wording... As I stated I am new to the raspberry pi system and don't know the correct terminology for it, if it would be called a controller in this instance then yes, I want to remove the phone as a controller and do it all from the Pi, is that possible? I me...
by LateDev
Thu Dec 26, 2013 1:38 pm
Forum: Beginners
Topic: Connecting Sensor that require 4.5 min I/P voltage to GPIO
Replies: 10
Views: 2989

Re: Connecting Sensor that require 4.5 min I/P voltage to GP

See the attachment... That tells you the operating Voltage, as in its supply Voltage range, and not the I/P Voltage, which is stated as TTL level. The O/P just needs a series resistor to the I/P with a bypass resistor from I/P to gnd, thus providing a Voltage divider. Easy enough to work out with O...
by LateDev
Thu Dec 26, 2013 2:17 am
Forum: Beginners
Topic: Leds and resistors
Replies: 21
Views: 3489

Re: Leds and resistors

As for the 50mA limit, that is the available current from the 3.3V supply. Interesting. So I did a quick search and found this which may help : http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/raspberry-pi/gpio-pin-electrical-specifications Current sourced by the outputs i...
by LateDev
Wed Dec 25, 2013 11:18 pm
Forum: Beginners
Topic: Leds and resistors
Replies: 21
Views: 3489

Re: Leds and resistors

Careful. There is a maximum total current from the GPIOs, and I think it is about 30mA. No Rurwin, its actually 50mA total, and about 15mA per I/O. No idea where you get that from, as the data sheet suggests otherwise. 16mA per I/O but will try and drive it High or Low, regardless of this. http://w...
by LateDev
Wed Dec 25, 2013 10:15 pm
Forum: Beginners
Topic: Controlling a solenoid
Replies: 13
Views: 5992

Re: Controlling a solenoid

Can you give specifics as to what current the Relay requires, or at the very least the coil resistance ? Whenever you want to test any cct out of this nature, you should replace the relay with a resistor, and make sure everything works. As far as missing out the flywheel diode, you musn't, unless yo...

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