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by MarkHaysHarris777
Sat Apr 25, 2015 11:20 am
Forum: C/C++
Topic: bcm2835 lib + SPI + manual CS
Replies: 5
Views: 976

Re: bcm2835 lib + SPI + manual CS

The above advice is correct, but not advised. Almost everyone will tell you to resist making your own CS. The reason is the precise timing. If you allow the system | libraries handle the clock line things will work much better because the timing is closer to the hardware and the interrupts, etc. ......
by MarkHaysHarris777
Sat Apr 25, 2015 11:16 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: how read data from DS3231
Replies: 24
Views: 8260

Re: how read data from DS3231

... you can try Dougie's config.txt entry... I know I'm going to ! ... but if you want to read the data yourself you're going to have to get into the spec sheet on the RTC and understand how its config register works, and how its data registers work; whether they are little-endian or big-endian and ...
by MarkHaysHarris777
Sat Apr 25, 2015 11:05 am
Forum: Beginners
Topic: Chipmunk BASIC on RasPi?
Replies: 16
Views: 3447

Re: Chipmunk BASIC on RasPi?

Ron, Thank you so much! I have Chipmunk BASIC running on my RPi b+ now, will test some tomorrow on my RPi 2B; my b+ is headless so I can't try the graphics yet; pumped about that! Thanks again... how did you know? I was all set to send off a letter to you asking for a port... and here it already is!...
by MarkHaysHarris777
Sat Apr 25, 2015 10:46 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: how read data from DS3231
Replies: 24
Views: 8260

Re: how read data from DS3231

Greetings, I understand. Reading the i2c bus is very confusing for everyone; do not feel like you're alone on that one! How you read i2c bus depends on the interface you are using (do you have an i2c block?) and whether you are using a library (like mraa, or other) or whether you are writing your ow...
by MarkHaysHarris777
Sat Apr 25, 2015 10:19 am
Forum: General discussion
Topic: Overlay
Replies: 6
Views: 1560

Re: Overlay

Of course there's a way... ... all you need to do is conceive it, believe it, research it, and then make it happen. The Raspberry PI comes with some rudimentary 'drivers' for the camera module. All of that code is open source. All you need to do is write your own 'driver' and overlay what ever you w...
by MarkHaysHarris777
Sat Apr 25, 2015 10:11 am
Forum: Troubleshooting
Topic: DHT22 problem
Replies: 3
Views: 620

Re: DHT22 problem

Please, do not cross post...

please read...

https://learn.adafruit.com/dht/overview



merci beaucoup
by MarkHaysHarris777
Sat Apr 25, 2015 10:09 am
Forum: Français
Topic: Problème capteur DHT22
Replies: 2
Views: 637

Re: Problème capteur DHT22

Bonjour,

Please read:

https://learn.adafruit.com/dht/overview


(use google translate if needs be)


merci beaucoup

8-)
by MarkHaysHarris777
Sat Apr 25, 2015 10:02 am
Forum: Troubleshooting
Topic: Epipany doesn't like image and freezes
Replies: 17
Views: 2323

Re: Epipany hate image and freeze

@ bonami2... The Epiphany browser will be only as good as your memory management skills, on the Raspberry PI I'm afraid. One of the raspi-config advanced options is 'split memory' for the gpu. It needs to be set at least to 256 M if you want Epiphany to work at all (you might try experimenting with ...
by MarkHaysHarris777
Sat Apr 25, 2015 9:52 am
Forum: General discussion
Topic: read multimeter values and store in sd card using raspberry.
Replies: 3
Views: 767

Re: read multimeter values and store in sd card using raspbe

i want to read multimeter values ( volts and currents) using raspberry pi. You intrigue me... do you want to 'make' your Raspberry PI 'into' a multimeter (volts amps), or are you trying to 'read' a multimeter that has, say, an i2c interface which may be 'read' by a micro-controller? You can read cu...
by MarkHaysHarris777
Fri Apr 24, 2015 6:45 am
Forum: Troubleshooting
Topic: Serial Output in numbers?
Replies: 6
Views: 801

Re: Serial Output in numbers?

In any case you are sending three bytes... that is probably not what you want. What you want to send is just one byte (8 bits) one character (very small binary integer) that represents the number 0, or 255, or 127, in decimal. 255 is the character 0xFF; 8 bits all on. 127 is the character 0x7F; firs...
by MarkHaysHarris777
Fri Apr 24, 2015 6:05 am
Forum: General programming discussion
Topic: Understanding GPIO
Replies: 3
Views: 1164

Re: Understanding GPIO

And, there is the mraa numbering system. Which system you will use depends on the board you have, the development environment you are going to use, and the library for that environment. This is the mraa pinout mapping for the RPi b+ and RPi 2B: http://iotdk.intel.com/docs/master/mraa/rasppi.html Be ...
by MarkHaysHarris777
Wed Apr 22, 2015 4:24 am
Forum: HATs and other add-ons
Topic: Display HDMI
Replies: 1
Views: 985

Re: Display HDMI

I know the feeling. hdmi_group=2 hdmi_mode=47 hdmi_drive=2 I set all of my overscan values to 7. My monitor will do 1920 but things are just too hard to see... so with the above settings my monitor comes up in 1440... by whatever... the overscan values 7 gives me 7pixels of margin and keeps all of t...
by MarkHaysHarris777
Wed Apr 22, 2015 3:49 am
Forum: Beginners
Topic: logon
Replies: 5
Views: 660

Re: logon

Also, I disable login to the desktop when I have multiple users on the system. This is a raspi-config option. Just have the machine bootup into a console that requires login. Once the user is logged in, then the user can 'startx' to get the desktop going with their userid. But this is where it gets ...
by MarkHaysHarris777
Wed Apr 22, 2015 3:44 am
Forum: Beginners
Topic: logon
Replies: 5
Views: 660

Re: logon

You have to be careful about this, because much of the system is setup for pi... video for instance; and other things. You need to authenticate your new user. Once you: sudo adduser <username> ... then you need a password: sudo passwd <username> ... it will prompt you for the new password twice... t...
by MarkHaysHarris777
Wed Apr 22, 2015 3:37 am
Forum: Troubleshooting
Topic: LCD 16x2
Replies: 7
Views: 1107

Re: LCD 16x2

Are you running as root with sudo?
by MarkHaysHarris777
Wed Apr 22, 2015 3:33 am
Forum: Automation, sensing and robotics
Topic: TXB0104 Level Shifter Usage?
Replies: 11
Views: 4514

Re: TXB0104 Level Shifter Usage?

There may only be one gnd pin on the chip itself (I use the breakout boards, personally) but the important thing is that each side has a ground that must be connected to gnd. You will need to identify Vccb (the high voltage reference pin) and Vcca (the low voltage reference pin) and make sure 5v is ...
by MarkHaysHarris777
Wed Apr 22, 2015 1:14 am
Forum: Troubleshooting
Topic: Browser rather crashy
Replies: 19
Views: 2869

Re: Browser rather crashy

Did you create a new user? If so, you need to add that user to the video group in /etc/group Also, did you split off memory for the gpu? Its a raspi-config option under advanced options. On the RPi b+ I'd give the gpu at least 128, but maybe 256. On the RPi 2B give the gpu at least 256; or Epiphany ...
by MarkHaysHarris777
Wed Apr 22, 2015 1:10 am
Forum: Automation, sensing and robotics
Topic: TXB0104 Level Shifter Usage?
Replies: 11
Views: 4514

Re: TXB0104 Level Shifter Usage?

see here https://learn.sparkfun.com/tutorials/txb0104-level-shifter-hookup-guide Vcc(b) is the high voltage side Vcc(a) is the low voltage side Each side has its own ground (and that's important!) make sure the grounds are solid. So, as an example, your 5v side should have the 5v connected to Vccb. ...
by MarkHaysHarris777
Wed Apr 22, 2015 1:01 am
Forum: Beginners
Topic: Can I damage my pi by "playing" with the GPIO
Replies: 7
Views: 1005

Re: Can I damage my pi by "playing" with the GPIO

Sanctimonious, much? OP owns their Pi so they can do as they please with it. Playing with the GPIO is a great way to learn, even if the only outcome is "I shorted the pins and now the Pi won't work. I won't do that again." To many people the Pi is a toy, albeit a high-tech one. hi ame, we'll just h...
by MarkHaysHarris777
Tue Apr 21, 2015 11:41 pm
Forum: Raspberry Pi OS
Topic: Help with device driver
Replies: 2
Views: 625

Re: Help with device driver

Is there a question in there?
by MarkHaysHarris777
Tue Apr 21, 2015 11:37 pm
Forum: Advanced users
Topic: Rebooting into a new OS.
Replies: 11
Views: 3115

Re: Rebooting into a new OS.

... welcome to boot-loaders. To boot into an OS (on any computer) you need a boot-loader. NOOBS is your boot-loader. . . . NOOBS isn't really a bootloader, it's a small linux distro which sets the reboot_part parameter and reboots. The actual bootloader is the firmware, which the pi doesn't run wit...
by MarkHaysHarris777
Tue Apr 21, 2015 11:23 pm
Forum: C/C++
Topic: Can't compile on Raspbian (RasPi 2)
Replies: 8
Views: 13388

Re: Can't compile on Raspbian (RasPi 2)

You might try this: http://stackoverflow.com/questions/20167411/how-to-compile-a-kernel-module-for-raspberry-pi you will also want to make sure your libc6 libc6-dev and libstdc++6-4.6-dev files are up-to-date. sudo apt-get install libc6-dev also, sudo apt-get update sudo apt-get upgrade Then follow ...
by MarkHaysHarris777
Tue Apr 21, 2015 10:30 pm
Forum: Advanced users
Topic: Rebooting into a new OS.
Replies: 11
Views: 3115

Re: Rebooting into a new OS.

... welcome to boot-loaders. To boot into an OS (on any computer) you need a boot-loader. NOOBS is your boot-loader. I have not seen it yet, but somebody out there sooner or later will get grub2 running on the Raspberry PI and then you will be able to boot into the OS by selecting it in grub. The bo...
by MarkHaysHarris777
Tue Apr 21, 2015 10:03 pm
Forum: Other projects
Topic: Trac on a Pi
Replies: 10
Views: 962

Re: Trac on a Pi

Are you having trouble installing the codes? Are you just looking for a PI user to provide a code|product review? Which OS are you running on your PI?
by MarkHaysHarris777
Tue Apr 21, 2015 9:58 pm
Forum: Off topic discussion
Topic: Pi tablet phone thing
Replies: 5
Views: 1087

Re: Pi tablet phone thing

Google is our friend. ;)

https://www.google.com/?gws_rd=ssl#q=ra ... t&tbm=shop

There are *many* hits on the net about this issue... do some homework, its fun!

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