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If your iPhone, iPad, or iPod touch won‘t turn on or is frozen

30/10/2017 Comments off

If your device has a frozen screen or doesn’t respond when you touch it, or becomes stuck when you turn it on, learn what to do.

If your screen is black or frozen

If your screen is black or frozen, you might need to force restart your device. A force restart won’t erase the content on your device. You can force restart your device even if the screen is black or the buttons aren’t responding. Follow these steps:

  • On an iPhone 8 or iPhone 8 Plus: Press and quickly release the Volume Up button. Then press and quickly release the Volume Down button. Finally, press and hold the Side button until you see the Apple logo.
  • On an iPhone 7 or iPhone 7 Plus: Press and hold both the Side and Volume Down buttons for at least 10 seconds, until you see the Apple logo.
  • On an iPhone 6s and earlier, iPad, or iPod touch: Press and hold both the Home and the Top (or Side) buttons for at least 10 seconds, until you see the Apple logo.

If your device still won’t turn on or start up

Plug in your device and let it charge for up to one hour.

After a few minutes, you should see the charging screen. 

 

If you don’t see the charging screen within an hour, or you see the connect to power screen, check the jack, USB cable, and power adapter. Make sure that everything is plugged in firmly, free of debris, and not damaged. You might want to try a different USB cable or power adapter.

If your device still doesn’t turn on, see what to do next.

If your device turns on but gets stuck during start up

If you see the Apple logo or a red or blue screen during startup, try these steps:

  1. Connect your device to a computer and open iTunes. If you don’t have a computer, try to borrow one, or go to an Apple Store or Apple Authorized Service Provider for help. 
  2. While your device is connected, force it to restart. 
    • On an iPhone 8 or iPhone 8 Plus: Press and quickly release the Volume Up button. Then press and quickly release the Volume Down button. Finally, press and hold the Side button until you see the recovery-mode screen.
    • On an iPhone 7 or iPhone 7 Plus: Press and hold the Side and Volume Down buttons at the same time. Keep holding them until you see the recovery-mode screen.
    • On an iPhone 6s and earlier, iPad, or iPod touch: Press and hold both the Home and the Top (or Side) buttons at the same time. Keep holding them until you see the recovery-mode screen.
  3. Don’t release the buttons when you see the Apple logo. Keep holding until you see the recovery mode screen.

 

  1. When you get the option to restore or update, choose Update. iTunes will try to reinstall iOS without erasing your data.

iTunes will download the software for your device. If it takes more than 15 minutes, your device will exit recovery mode and you’ll need to repeat steps 2 and 3.

 
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Categories: Constructeur, Matériel Tags: ,

People or Object counter Circuit diagram using IC 555 and IC 4026

26/06/2017 Comments off

People / Object counter circuit have a wide variety of applications in Banks, Hospitals, factories etc. This project focuses on building an effective counter using IR as a sensing element and capable of counting from 0 to 999. This project uses Two simple IC’s ( IC 555 & IC 4026 ) with IR transmitter and Receiver to detect the incoming people/object. 

This Project comprises of Three parts

  1. IR Transmitter
  2. IR Receiver
  3. 7 Segment drivers

IR TRANSMITTER:

Freq = 1.45 / ( R3 + 2R1 ) C2IR transmitter was wired around Astable multivibrator using IC 555. As we all know that multivibrator produce square wave pulses and we gotta fix the frequency of the output signal as 38 Khz since we are about to use TSOP 1738 an Infra red sensor which is capable of detecting signals of 38 Khz. The frequency of the astable depends on R1,R3 and C2. So lets do some math

         = 1.45 / (470 + 2 * 1690 ) * 100 * 10 

         = 37.6 Khz

So we have fixed the IR frequency of 38 Khz and now Transmitter part is done.

Please note that i have used a simple IR transceiver module (brown board  – right top) for this project to make things simple. You can use use IR module like i did if you have any. If not build the IR transmitter using IC 555 as shown in above circuit. The receiver part was given in the below circuit diagram.

Lire la suite…

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Categories: Matériel Tags:

DIY Stopwatch made out of Digital IC 4026 and 4017

26/06/2017 Comments off

diy-stopwatch-electronics-project

Today we are about to see how to build a DIY stopwatch just using Digital IC’s 4026 and 4017. The most highlighting feature about this project is the fact that it doesn’t use any MCU to do the job. Even though using an MCU will be a lot better option still this project will be a great DIY for those who love to play with Digital chips. 

BLOCKS OF DIY STOPWATCH:

  1. Oscillator
  2. Display

OSCILLATOR BLOCK:

Oscillator provides the clock source for stopwatch we are about to build. The oscillator should provide an output clock frequency of about 1Hz. There are plenty of ways to do this but each method might differ in accuracy of output wave produced. Even a simple 555 timer can be used here, but temperature drift might affect the accuracy of output. The deviation of output might not be that big but its good to have it under consideration.

Crystal powered oscillator will be the perfect solution for this problem. We are not going to discuss the oscillator section briefly in this article since this 1 Hz oscillator circuit will do a pretty good job for our DIY stopwatch project. You can always use other 1Hz clock generator circuits rather than the crystal oscillators provided your application have some tolerance on the accuracy.

DISPLAY BLOCK:

digital-diy-stopwatch-circuit-diagramThe display block uses 4 common cathode 7 segment for displaying the seconds and minutes of the count. The 7 segments marked as “S” for seconds and “M” for displaying minutes in the above circuit diagram. Use a 9v battery to power this block. Switch “ON/OFF” used to turn the counter ON or OFF. Use switch START/STOP to start and stop counting of Stopwatch.

Four IC 4026 (Decade counter with decoder which converts counter values to 7 segment outputs) was used to drive each of the 7 segment displays. The 1Hz clock from oscillator is fed into CLK pin of U1. With each incoming pulse in to the CLK pin of this IC ,the counter increments by one which in turn gets decoded and displays the value in 7 segment accordingly. When the count reaches the maximum value of 9 a high signal was sent out through the pin 5 CO of U1. This will the clock input to the next IC U2. So thus when U1 segment counts up to 9 CO signal will sent out to U2. Then it starts displaying the value 1 in its segment.

The segment associated with U2 will count up to 9 before returning to 0. But to stay withing the limit of 60 seconds we need to stop U2 before it hits 6 mark. So here comes along another IC 4017 (Johnson counter increments count values from Q0 to Q9 with each incoming input pulse) which is used to reset the IC U2 before it hits the 6 mark in its segment. To do so we have connected the Q6 pin to Reset pin (MR) of U2 and Reset pin of U5 itself. The clock from U1 was used by both U2 and U5 in order to keep the count similar for providing correct reset point. When the count in U2 and U5 reaches from 0 to 6 the Q6 pin in U5 goes high resetting itself and U2. Thus this sets the boundary of 60 seconds for our stopwatch.

The output from Q6 acts as clock source for the IC U3. So when 60 seconds count gets elapsed the minute segment associated with U3 increments to 1. When this U3 counts up to 9 the CO pin goes high which feeds clock to the chip U4. This is similar to the way U1 fed clock to U2. Then U4 starts counting from 1 with every clock input from CO of U3 and can count up to 9. Thus U3 and U4 segment combined can count up to 99. Therefore this DIY stopwatch has a count limitation of 99 minutes after it starts counting again from 0 minutes.

NOTE:

  • Use current limiting resistors of 470 ohm should to connect the 7 segment pins from IC 4026. I have omitted it in the circuit diagram for simplicity.
  • Use pull down resistors R1 and R2 to maintain pins at ground potential and prevent the chips from short.
  • You can expand this stopwatch to display hours by adding two segments and 4026 more.

Hope you all will have fun building this stopwatch. Please comment below if you have any comments, suggestions and improvements with this project.

 
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Categories: Matériel Tags:

Residual-current device

21/06/2017 Comments off
From Wikipedia, the free encyclopedia
 

An RCD does not provide protection against unexpected or dangerously high current (called spikes or surges) when current is flowing in the usual wires in the circuit, therefore it cannot replace a fuse or protect against overheating or fire risk due to overcurrent (overload) or short circuits if the fault does not lead to current leakage. Therefore, RCDs are often used or integrated as a single product along with some kind of circuit breaker, such as a fuse or miniature circuit breaker (MCB), which adds protection in the event of excessive current in the circuit (the resulting RCD with overcurrent protection called an RCBO). RCDs also cannot detect the situation where a human accidentally touches both conductors at the same time, since the flow of current through an expected device, an unexpected route, or a human, are indistinguishable if the current returns through the expected conductor.

RCDs are usually testable and resettable devices. Commonly they include a button that when pressed, safely creates a small leakage condition, and a switch that reconnects the conductors when a fault condition has been cleared. Depending upon their design, some RCDs disconnect both the energized and return conductors upon a fault, while others only disconnect the energized conductor and rely upon the return conductor being at ground (earth) potential. The former are commonly known as « double-pole » designs; the latter as « single-pole » designs. If the fault has left the return wire « floating » or not at its expected ground potential for any reason, then a single-pole RCD will leave this conductor still connected to the circuit when it detects the fault.

Lire la suite…

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HP-41C Synthetic Programming

23/11/2016 Comments off

Caution

Many of these instructions were intentionally left out because used incorrectly they can confuse the calculator and cause either a lockup or a « Memory Lost » state. (If you get into the former state, you may need to remove the batteries to reset the calculator.)

You should backup anything important before first engaging in Synthetic Programming.

How Synthetic Instructions Work

HP-41 instructions are one or more bytes long. The calculator will only allow certain sequences, but with the tool below, you’ll be able create new sequences by entering code that the calculator allows and then grabbing bytes out of this code to create different instructions. These new sequences allow access to additional characters, additional sounds, more alpha editing commands, easy control of the calculator through direct access to system registers, etc. They make it possible to do new things and to reduce the size and execution time of programs. The byte grabber described below will allow you to remove individual bytes from programs you create so the the bytes that remain are interpreted differently.

Creating a Byte Grabber

You can use the following steps to create a Byte Grabber. Make sure to follow the steps exactly. If it doesn’t work the first time, try again. Note that the first step is a master clear so save anything important to cards, tape, or disk now!

  1. Remove any accessory modules.
  2. Do a Master clear by holding down the backspace key while turning on the calculator. The Display will show MEMORY LOST.
  3. Assign « + » to the LN key by pressing shift ASN ALPHA shift + ALPHA LN.
  4. Assign « DEL » to the LOG key by pressing shift ASN ALPHA D E L ALPHA LOG.
  5. Press PRGM to witch to program mode. The display should show 00 REG 45.
  6. Start catalog 1 by pressing shift CATALOG 1 and press R/S immediately before the display blinks. If the display blinks, you waited too long. Repeat this step as many times as necessary to get the R/S pressed before the display blinks. (The display will show the .END. instruction both before and after the blink, but you must press R/S before the blink.)
  7. Press the ALPHA key to go into Alpha mode.
  8. Press the backspace key. The display should now show 4094 RCL 01.
  9. Press ALPHA to leave Alpha mode.
  10. Press shift GTO .005 and you should see 05 LBL 03.
  11. Press USER (if necessary) to enter User mode.
  12. Press LOG 003 which uses the assignment you made earlier to DEL 3 steps. You should now see 04 STO 01.
  13. Press ALPHA to go back into Alpha mode.
  14. Press ? A A A A A A (Everything after the first A will probably display as « -« s.) Press exactly 6 A’s!
  15. Press PRGM to leave program mode and ALPHA to leave Alpha mode.
  16. Press shift GTO . . (press both dots)

The byte grabber should now be assigned to the LN key. Press AND HOLD the LN key which should display XROM 28,63. Keep holding the key until the calculator displays NULL because you don’t want to execute the byte grabber now. This would be a good time to save the calculator’s status on a card by pressing XEQ ALPHA W S T S ALPHA in case you accidentally destroy the byte grabber later.

Be careful in using the byte grabber. You may get a « MEMORY LOST » or lock the calculator if you use it incorrectly. If the latter happens, remove the batteries for a few seconds and return them. If that doesn’t work, try turning the calculator on a few times with the batteries out or leave them out for several hours. Lire la suite…

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Ubuntu Check RAM Memory Chip Speed and Specification From Within a Linux System

22/06/2016 Comments off

I want to add more RAM to my server running Ubuntu Linux. How do I find out my current RAM chip information such as its speed, type and manufacturer name within a Linux system without opening the case?

You need to use the dmidecode command which is a tool for dumping a computer’s DMI (some say SMBIOS) table contents in a human-readable format. This table contains a description of the system’s hardware components (such as RAM), as well as other useful pieces of information such as serial numbers and BIOS revision. Thanks to this table, you can retrieve hardware information without having to probe for the actual hardware. Open a command-line terminal (select Applications > Accessories > Terminal), and then type:

$ sudo dmidecode --type memory

OR

# dmidecode --type memory | less

OR

$ sudo dmidecode --type 17

Sample outputs:

# dmidecode 2.10
SMBIOS version fixup (2.51 -> 2.6).
SMBIOS 2.6 present.
Handle 0x0011, DMI type 16, 15 bytes
Physical Memory Array
	Location: System Board Or Motherboard
	Use: System Memory
	Error Correction Type: None
	Maximum Capacity: 4 GB
	Error Information Handle: Not Provided
	Number Of Devices: 4
Handle 0x0012, DMI type 17, 27 bytes
Memory Device
	Array Handle: 0x0011
	Error Information Handle: No Error
	Total Width: 72 bits
	Data Width: 64 bits
	Size: 2048 MB
	Form Factor: DIMM
	Set: 1
	Locator: DIMM#1A
	Bank Locator: Bank 1
	Type: DDR2
	Type Detail: Synchronous
	Speed: 667 MHz
	Manufacturer: Not Specified
	Serial Number: Not Specified
	Asset Tag: Not Specified
	Part Number: Not Specified
Handle 0x0013, DMI type 17, 27 bytes
Memory Device
	Array Handle: 0x0011
	Error Information Handle: No Error
	Total Width: 72 bits
	Data Width: 64 bits
	Size: 2048 MB
	Form Factor: DIMM
	Set: 1
	Locator: DIMM#2A
	Bank Locator: Bank 2
	Type: DDR2
	Type Detail: Synchronous
	Speed: 667 MHz
	Manufacturer: Not Specified
	Serial Number: Not Specified
	Asset Tag: Not Specified
	Part Number: Not Specified
Handle 0x0014, DMI type 17, 27 bytes
Memory Device
	Array Handle: 0x0011
	Error Information Handle: No Error
	Total Width: 72 bits
	Data Width: 64 bits
	Size: 2048 MB
	Form Factor: DIMM
	Set: 1
	Locator: DIMM#1B
	Bank Locator: Bank 1
	Type: DDR2
	Type Detail: Synchronous
	Speed: 667 MHz
	Manufacturer: Not Specified
	Serial Number: Not Specified
	Asset Tag: Not Specified
	Part Number: Not Specified
Handle 0x0015, DMI type 17, 27 bytes
Memory Device
	Array Handle: 0x0011
	Error Information Handle: No Error
	Total Width: 72 bits
	Data Width: 64 bits
	Size: 2048 MB
	Form Factor: DIMM
	Set: 1
	Locator: DIMM#2B
	Bank Locator: Bank 2
	Type: DDR2
	Type Detail: Synchronous
	Speed: 667 MHz
	Manufacturer: Not Specified
	Serial Number: Not Specified
	Asset Tag: Not Specified
	Part Number: Not Specified
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Change the firewall manually to make your Synology more safe!

08/03/2016 Comments off

Source: Changzhou Chen

The default firewall in the Control Panel is so poor because of the poor design of Synology’s firewall policy. You can not use the white list in the global environment if you have both IPv4 or IPv6 network environment. To decrease the risk of being hacked, I’ve decided to change the firewall manually. We should use iptables and ip6tables to change both IPv4 and IPv6 firewall. If you don’t have the need for IPv6 network environment, you can ignore the ip6tables part.

Warning: If you don’t have enough IT experience, you should run the following sections carefully. Maybe you will lose your connection to your Synology and find it hard to connect to it again.

I wrote some IPv4 rules, the following code section is part of the rule file, you can run the iptables-save to export the rule file:

DiskStation> iptables-save > ipv4
# For your simple reference, I delete the
# unuseful part of rule file which exported by iptables-save. The following
# part is completely different from the file exported by iptables-save.
DiskStation> cat ipv4
*filter
:INPUT DROP # Drops all inbound connections that doesn't use the following rules
:FORWARD ACCEPT # It may be default, you can ignore it
:OUTPUT ACCEPT # It may be default, you can ignore it
-A INPUT -i lo -j ACCEPT # Allows all loopback (lo0) traffic
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT # Accepts all established inbound connections
-A INPUT -s 192.168.1.1/255.255.255.0 -j ACCEPT # Allows your Intranet inbound connections
-A INPUT -s 1.2.3.4 -j ACCEPT # Allows the specified ip address inbound connections
COMMIT

After run the iptables-restore and iptables -L, you can see the following result:

DiskStation> iptables-restore < ipv4
DiskStation> iptables -L
Chain INPUT (policy DROP)
target     prot opt source               destination
DEFAULT_INPUT  all  --  anywhere             anywhere
Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
Chain DEFAULT_INPUT (1 references)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED
ACCEPT     all  --  192.168.1.0/24       anywhere
ACCEPT     all  --  1.2.3.4              anywhere

Lire la suite…

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Digital Equipment Corporation PDP-12

23/02/2016 Comments off

The PDP-12 was a 12 bit machine introduced in 1969. It sold for $27,900. The PDP-12 was designed as a successor to the LINC-8 and was compatible with LINC-8 software.

DEC.PDP-12.1963.102646098

Programmed Data Processor (PDP) was a series of minicomputers made and marketed by the Digital Equipment Corporationfrom 1957 to 1990. The name « PDP » intentionally avoided the use of the term « computer » because, at the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines, and the venture capitalists behind Digital (especially Georges Doriot) would not support Digital’s attempting to build a « computer »; the word « minicomputer » had not yet been coined.[citation needed] So instead, Digital used their existing line of logic modules to build a Programmed Data Processor and aimed it at a market that could not afford the larger computers.

The various PDP machines can generally be grouped into families based on word length.

Members of the PDP series include:

PDP-1

The original PDP, an 18-bit machine used in early time-sharing operating system work, and prominent in MIT’s early hacker culture, which was to lead to the (Massachusetts) Route 128 hardware startup belt (DEC’s second home, Prime Computer, etc.). What is believed to be the first video game, Spacewar!, was developed for this machine, along with the first known word processing program for a general-purpose computer, « Expensive Typewriter ».

PDP-2

A number reserved for an unbuilt, undesigned 24-bit design.

PDP-3

First DEC-designed (for US « black budget » outfits) 36-bit machine, though DEC did not offer it as a product. The only PDP-3 was built by the CIA’s Scientific Engineering Institute (SEI) in Waltham, MA to process radar cross section data for the Lockheed A-12 reconnaissance aircraft in 1960.[1][2] Architecturally it was essentially a PDP-1 controlling[citation needed] a PDP-1 stretched to 36-bit word width.[3]

PDP-4

pdp4

PDP-4

18-bit machine intended to be a slower, cheaper alternative to the PDP-1; it was not considered commercially successful. All later 18-bit PDP machines (7, 9 and 15) were based on a similar, but enlarged instruction set, more powerful, but based on the same concepts as the 12-bit PDP-5/PDP-8 series. One customer of these early PDP machines was Atomic Energy of Canada. The installation at Chalk River, Ontario included an early PDP-4 with a display system and a new PDP-5 as interface to the research reactor instrumentation and control.

PDP-5

DEC’s first 12-bit machine. Introduced the instruction set later expanded, in the PDP-8, to handle more bit rotations and to increase the maximum memory size from 4K words to 32K words. It was the first computer series with more than 1,000, then 10,000 built, which was a large number in the decade after ENIAC/UNIVAC builders predicted that 3 computers would serve the nations computing needs.

PDP-6

pdp6

PDP-6

36-bit timesharing machine. Very elegant architecture; introduced the instruction set later used in the PDP-10 and DECSYSTEM-20. It was considered by its detractors a large minicomputer or, by DEC fans especially, Big Iron – a mainframe As a timesharing machine, it constantly outran the batch-oriented IBM System/360 and even IBM System/370-series mainframes.

PDP-7

pdp7

PDP-7

Replacement for the PDP-4; DEC’s first wire-wrapped machine. The first version of Unix, and the first version of B, a predecessor of C, were written for this machine at Bell Labs, as was the first version (by DEC) of MUMPS.

 

 

 

 

 

 

PDP-8

R00000254-hp

PDP-8

12-bit machine with a tiny instruction set; DEC’s first major commercial success and the start of the minicomputer revolution. Many were purchased (at discount prices, a DEC tradition, which also included free manuals for anyone who asked during the Ken Olsen years) by schools, university departments, and research laboratories. Later models were also used in the DECmate word processor and the VT-78 workstation. It is reported that Edson de Castro, who had been a key member of the design team, left to form Data General when his design for a 16-bit successor to the PDP-8 was rejected in favour of the PDP-11; the « PDP-X » did not resemble the Data General Nova,[4] although that is a common myth.

LINC-8

A hybrid of the LINC and PDP-8 computers; two instruction sets. Progenitor of the PDP-12.

PDP-9

Successor to the PDP-7; DEC’s first micro-programmed machine. It featured a speed increase of approximately twice that of the PDP-7. The PDP-9 was also one of the first small or medium scale computers to have a keyboard monitor system based on DIGITAL’s own small magnetic tape units (DECtape).[5] The PDP-9 established minicomputers as the leading edge of the computer industry.

PDP-10

36-bit timesharing machine, and fairly successful over several different models. The instruction set was a slightly elaborated form of that of the PDP-6.

PDP-11

11_panel_2

PDP-11

PanelInCase_Side

PDP-11/70

The archetypal minicomputer; a 16-bit machine and another commercial success for DEC. The LSI-11 was a four-chip PDP-11 used primarily for embedded systems. The 32-bit VAX series was descended from the PDP-11, and early VAX models had a PDP-11 compatibility mode. The 16-bit PDP-11 instruction set has been very influential, with processors ranging from the Motorola 68000 to the Renesas H8 and Texas Instruments MSP430, inspired by its highly orthogonal, general-register oriented instruction set and rich addressing modes. The PDP-11 family was extremely long-lived, spanning 20 years and many different implementations and technologies.

PDP-12

PDP-12

PDP-12

MINOLTA DIGITAL CAMERA

Descendant of the LINC-8; with slight redesign, and different livery, officially followed by, and marketed as, the « Lab-8 ». See LINC and PDP-12 User Manual.

PDP-13

Designation was not used, apparently due to superstition.

PDP-14

A machine with 12-bit instructions, intended as an industrial controller (PLC). It had no data memory or data registers; instructions could test Boolean input signals, set or clear Boolean output signals, jump conditional or unconditionally, or call a subroutine. Later versions (for example, the PDP-14/30) were based on PDP-8 physical packaging technology. I/O was line voltage.

PDP-15

PDP-15

PDP-15

DEC’s final 18-bit machine. It was its only 18-bit machine constructed from TTL integrated circuits rather than discrete transistors, and, like every DEC 18-bit system (except mandatory on the PDP-1, absent on the PDP-4) had an optional integrated vector graphics terminal, DEC’s first improvement on its early-designed 34n where n equalled the PDP’s number. Later versions of the PDP-15 ran a real-time multi-user OS called « XVM ». The final model, the PDP-15/76 used a small PDP-11 to allow Unichannel peripherals to be used.

PDP-16

PDP-16/M

PDP-16/M

A « roll-your-own » sort of computer using Register Transfer Modules, mainly intended for industrial control systems with more capability than the PDP-14. The PDP-16/M was introduced as a standard version of the PDP-16.

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AppleKeyboard on Ubuntu

07/12/2015 Comments off

Source: ubuntu.com

Preface

Since Ubuntu 8.04 (Hardy Heron) the USB aluminum Apple Keyboard has not worked correctly. A change was added to the Ubuntu Linux kernel to make Apple MacBook keyboards gain additional functionality to their limited laptop style keyboard (Ubuntu bug #162083). Unfortunately this code change has some side effects for owners of the full size USB aluminum Apple Keyboard:

  • Function keys have media functions as default (as the printing on the keycaps indicates). To access the regular F-key functionality, the « fn » key must be pressed and held (except for F5 and F6, which are inverted in this respect). (Ubuntu bug #201711)
  • On international (non-US) keyboards, two keys are swapped with respect to the printing on the keycaps. (Ubuntu bug #214786)

Both issues may be straightened out with two configurable module parameters (http://bugzilla.kernel.org/show_bug.cgi?id=10818), as shown below.

To make the keyboard behave more like a standard PC keyboard (but against the orinal printing on the keycaps), additional steps are necessary:

  • Map SysRQ, Scoll Lock, and Pause keys to F13-F15: This still requires a patch that adds a configurable option to the kernel module, or a « keyfuzz » workaround (#262408).
  • Swap the cmd and super keys: (hid_apple patch) or keyfuzz workaround.

A tar archive containing all workarounds can be found at (un-apple-keyboard)

If you would like to have a better integration, please help by enhancing the patches to implement proper module parameters, and submitting them to the upstream kernel developers. See also: Trouble With Apple Keyboard On Ubuntu

To find the the keycode of any key that you want to modify, simply run in a terminal

xev | sed -n ‘s/^.*keycode *\([0-9]\+\).*$/keycode \1 = /p’

Then you can find the List of Keysyms Recognised by Xmodmap:

http://wiki.linuxquestions.org/wiki/List_of_Keysyms_Recognised_by_Xmodmap

http://wiki.linuxquestions.org/wiki/ConfiguRing_keyBoards

Default Behavior

This section describe the default behavior of every Apple keyboard.

Apple slim aluminum keyboard (0220)

wired_1_20070813a.jpg

  • Characters that are not printed on the keycaps (~,{},[],…) can still be generated as on a standard PC keyboard.
  • Even if the @ is printed on another keycap as on the standard PC layout, that key will only behave like the standard PC layout key and not generate the @. Use your localized standard PC layout key (combination) to generate the @.
  • ‘fn’+’F-Key’ -> triggers the regular F-Key
  • ‘fn’+’Enter’ -> Insert
  • ‘fn’+’Backspace’ -> Delete
  • ‘fn’+’Up’ -> PageUp
  • ‘fn’+’Down’ -> PageDown
  • ‘fn’+’Left’ -> Home
  • ‘fn’+’Right’ -> End
  • ‘Clear’ behaves like ‘NumLock‘ (Numlock may also be switched by pressing fn-F6 twice)

(See #262408 as there is patch submit to map F13, F14 and F15 to the otherwise missing PrintScreen, ScrollLock and Pause keys.)

Lire la suite…

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Categories: Matériel, Système Tags: ,

How to drive a 7 segment display directly on Raspberry Pi in Python

20/11/2015 Comments off

7 segment displayLast week I bought some 4-digit, 7-segment displays to experiment with. Strangely enough it was something I’d never tried before, so I was interested to see how they work. I googled around looking to see if someone else had done this before. It seems there are several different sorts of 7-segment displays, so you have to find a good match for the one you’ve bought.

You can get them in various guises including: i2c backpack; 12 pins; 16 pins; resistors built-in; common anode; common cathode etc.

The ones I bought are 12 pin, bare, no backpack, no PCB, no resistors, common cathode. Here’s what they look like…

7-segment display – rear

7-segment display – rear

7-segment display

7-segment display

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