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by Milliways
Wed Feb 11, 2015 5:00 am
Forum: Advanced users
Topic: Pi B 2 Processors
Replies: 7
Views: 3145

Pi B 2 Processors

I have just received my B2.
I noticed `/proc/cpuinfo` shows 4 processors but `lshw` shows cpu 1-3 disabled.

Are they in fact disabled?
I didn't really expect the new kernel to be using all cores yet, but how else would you explain benchmarking showing 6x performance?
by Milliways
Sat Jan 31, 2015 8:04 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Reading serial port in termios canonical mode
Replies: 8
Views: 4711

Re: Reading serial port in termios canonical mode

I am having difficulty understanding exactly you are asking. You may find the following code useful. This is an implementation of the fgets function which only expects normal Linux line endings. You can use int serialDataAvail (int fd) ; to check for data. #include <stdio.h> #include <termios.h> #in...
by Milliways
Mon Jan 26, 2015 12:07 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: WiringPi I2C library to get 16bit value
Replies: 2
Views: 4827

WiringPi I2C library to get 16bit value

I have used the WiringPi I2C library to perform simple byte transfers between a Raspberry Pi and an Arduino (using function wiringPiI2CRead). I want to get the Arduino to return 16bit word values, but am at somewhat of a loss. Arduino has `Wire.write(data, length)` which I could use; WiringPi has `i...
by Milliways
Sat Jan 03, 2015 7:09 am
Forum: General discussion
Topic: Searching Raspberry Pi Site
Replies: 2
Views: 484

Searching Raspberry Pi Site

I have tried to use the Search a few times, but the results have been less than successful. Practically every search seems to ignore the terms I want to search for. I can understand limiting search for short or common terms, but not many. Are these "ignored terms" documented? Is it possible override...
by Milliways
Thu Jan 01, 2015 9:38 am
Forum: Raspbian
Topic: not able to connect to hidden wifi
Replies: 5
Views: 998

Re: not able to connect to hidden wifi

Include `scan_ssid=1` in `/etc/wpa_supplicant/wpa_supplicant.conf `
by Milliways
Thu Jan 01, 2015 9:24 am
Forum: HATs and other add-ons
Topic: Gertboard, B+ Mount
Replies: 1
Views: 1752

Re: Gertboard, B+ Mount

I don't know this "mount" but I can't see it being much less clumsy. The Gertboard was designed for a 26 pin male connector. The following is my adaptation for the assembled Gertboard to allow a 26 pin cable. For the B+ you need a 40-26 pin cable (easily made from an old PATA cable). http://www.rasp...
by Milliways
Wed Nov 26, 2014 12:39 am
Forum: Advanced users
Topic: Model B+ documentation
Replies: 6
Views: 2463

Model B+ documentation

The Raspberry Pi Model B seems to be well documented. There are lots of guides and trouble shooting hints. The Model B+ does NOT seems to be well documented. (This is made even harder due to the unfortunate name, as you can't search for '+'). I can't find any description of the LEDs on the newer boa...
by Milliways
Fri Nov 07, 2014 7:19 am
Forum: Advanced users
Topic: B+ Pins
Replies: 1
Views: 1398

B+ Pins

I have updated Gordon Henderson's pins for the B+
I was going to upload them, but this site won't allow pdf or tex!!

http://binnie.id.au/Downloads/pins.pdf
http://binnie.id.au/Downloads/pins.tex
by Milliways
Tue Oct 21, 2014 7:14 am
Forum: Advanced users
Topic: Using an iPad as a passive display for a Pi over USB
Replies: 39
Views: 30313

Re: Using an iPad as a passive display for a Pi over USB

The Pi's will 99% certain have the same name as they'll be cloned off the same master card (as teacher won't have time/effort to change the host names on them ) :( I clone my SD card for use on multiple Pi. It is a trivial task to change `/etc/hostname`. It would be possible to do this in a script ...
by Milliways
Tue Oct 21, 2014 7:04 am
Forum: Advanced users
Topic: Suspend to RAM and Suspend to disk support for Raspberry Pi
Replies: 25
Views: 12213

Re: Suspend to RAM and Suspend to disk support for Raspberry

Lets reiterate a few things : We can adjust CPU frequency within Linux . You can turn off USB and Ethernet within Linux , but you may be unable to turn it on without restarting. You can turn off video output completely via the tvservice tool. You can turn off sound and some LEDs , and with a patch ...
by Milliways
Mon Oct 20, 2014 1:52 am
Forum: Advanced users
Topic: Using an iPad as a passive display for a Pi over USB
Replies: 39
Views: 30313

Re: Using an iPad as a passive display for a Pi over USB

Hi All; [*]Finding the IP address of a particular Pi in headless mode is a pain (appreciated there are a number of workarounds for this).. I cannot help with direct connection, but there is no problem connecting to a Pi without knowing the address. Install `netatalk` on the Pi, which makes it disco...
by Milliways
Tue Oct 07, 2014 5:48 am
Forum: Raspbian
Topic: What does git-core do and why is it marked obsolete
Replies: 1
Views: 962

What does git-core do and why is it marked obsolete

A year or more ago I installed WiringPi. The instructions started off with:- `sudo apt-get install git-core` I have been looking at some issues (specifically WHY git installs 3700 lines of functions in the login script) and discovered `git-core` is marked obsolete. Is there any reason why it is need...
by Milliways
Mon Sep 29, 2014 10:17 am
Forum: Advanced users
Topic: Powering Raspberry Pi through the GPIO by a 3 Pin C14
Replies: 10
Views: 1832

Re: Powering Raspberry Pi through the GPIO by a 3 Pin C14

Hi Raspberry Pi Community, Anyone ever done anything like this? Of course! Most Pi users do; we use a switch mode power unit (apparently called `wall-warts` in some places). I think you are asking can you build your own. Certainly you can; it will cost many times that of a mass produced item, and u...
by Milliways
Wed Sep 24, 2014 12:36 am
Forum: HATs and other add-ons
Topic: How to measure Voltage on B+
Replies: 6
Views: 9656

Re: How to measure Voltage on B+

The easiest way to measure the voltage is through the 40 pin connector (pin 2 5V, pin 6 Gnd). This is effectively the same as measuring TP1 on the model B. The test points referred to in other answers are OK, but measuring on the bottom of the board is much more difficult. You cannot damage the Pi b...
by Milliways
Sun Sep 21, 2014 9:15 am
Forum: Raspbian
Topic: Installing via MacOS
Replies: 6
Views: 1236

Re: Installing via MacOS

If you try to install (or even copy) using a normal disk id e.g. /dev/disk2 it can take a LONG time. If you use raw disk mode /dev/rdisk2 it should only take ~20 minutes for an 8GB card.

Post your `dd` command line if you need more help.

PS type Ctl+T in the terminal to show progress
by Milliways
Mon Sep 08, 2014 3:13 am
Forum: HATs and other add-ons
Topic: ATmega microcontroller can't be programmed (solved)
Replies: 2
Views: 1800

Re: ATmega microcontroller can't be programmed RESOLVED

I have resolved the problem, but am posting this for anyone else who has a similar problem. I had the PB5 pin connected to a buffer, but had not realised that PB3-5 are connected to the ISP socket on the Gertboard. (The Gertboard manual doesn't make this clear - I had to look at the schematic and AT...
by Milliways
Sat Aug 30, 2014 7:35 am
Forum: HATs and other add-ons
Topic: ATmega microcontroller can't be programmed (solved)
Replies: 2
Views: 1800

ATmega microcontroller can't be programmed (solved)

I have a Gertboard which I have used successfully with my Pi, and it mostly works now, but I am unable to upload any sketches to the ATmega microcontroller. I tried re-initialising with `avrsetup` which resulted in the following error message:- avrdude: AVR device not responding avrdude: initializat...
by Milliways
Sat Jul 19, 2014 4:51 am
Forum: General discussion
Topic: Pi B+ won't shutdown? Tying pin 28 to GND seems to solve it
Replies: 57
Views: 13711

Re: Pi B+ won't shutdown. Which Port brings it back up?

When the pi is halted using sudo halt or similar, pulling pin 5 low will make it boot up again.

This is implemented in bootcode.bin as documented
http://elinux.org/RPI_safe_mode#Wake_from_Halt.5B1.5D
by Milliways
Sun May 18, 2014 1:40 am
Forum: Advanced users
Topic: Set overscan from script
Replies: 2
Views: 840

Re: Set overscan from script

ukscone wrote:you could use bits from set_overscan https://github.com/ukscone/set_overscan to do it
Looks good. I will give it a go. It also looks like I could just use fbset If I know the offsets.
by Milliways
Sun May 18, 2014 1:11 am
Forum: Advanced users
Topic: Set overscan from script
Replies: 2
Views: 840

Set overscan from script

I am running Raspbian and normally use a DVI monitor connected via hdmi. Occasionally I connect to my analog TV (to view movies), but need to set a different aspect ratio and overscan. I can set aspect with /opt/vc/bin/tvservice -c "PAL 16:9" Is there any way I can set `overscan` from a script, or a...
by Milliways
Wed May 07, 2014 1:51 pm
Forum: Advanced users
Topic: Protect GPIO
Replies: 8
Views: 4332

Re: Protect GPIO

The Zener diode provides some protection, but is not the best (or cheapest) method. The conventional solution is to use a clamp diode to 3.3V which limits voltage to 3.3 + 0.7V. A Schottky diode limits the voltage rise to a lower value. I don't want to start an arguement, but I would be interested ...
by Milliways
Sat May 03, 2014 3:07 am
Forum: HATs and other add-ons
Topic: Gertboard Adaptor
Replies: 0
Views: 2131

Gertboard Adaptor

The Gertboard is a great tool for experimenting with the Pi GPIO and ad-hoc projects. Unfortunately the assembled Gertboard does not come with a header for the Pi, but has a connector mounted. This means it makes an unwieldy package, and is unusable with a Pi in a case. (It is unfortunate they didn'...
by Milliways
Sat May 03, 2014 2:48 am
Forum: Advanced users
Topic: Protect GPIO
Replies: 8
Views: 4332

Re: Protect GPIO

The Zener diode provides some protection, but is not the best (or cheapest) method.
The conventional solution is to use a clamp diode to 3.3V which limits voltage to 3.3 + 0.7V. A Schottky diode limits the voltage rise to a lower value.

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