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76

Some background The most important thing you should know is that the RaspberryPi is a strange beast where the ARM CPU is the not main CPU - it's only a co-processor to the VideoCore GPU. When the RaspberryPi starts, a GPU blob is read from the SD card to the L2 cache and executed. This code then brings up all the important peripherals (RAM, clocks etc) and ...


25

Starting with the default configuration, or one you know works already, is a good idea. Beware that for the Pi 2, you should use: make bcm2709_defconfig Instead of bcmrpi_defconfig. Note that if you want to avoid clobbering an existing kernel install of the same version, set the General setup -> Local version - append to kernel release string to a unique ...


24

Loading modules at boot is a little different to running startup commands. In Debian: Add the module name as a new line in /etc/modules In Arch Linux: Add the module name to the module array in /etc/rc.conf, the line should look like this: modules=(snd_bcm2835) Or for the new systemd configuration: echo "snd_bcm2835" | sudo tee -a /etc/modules-load.d/...


20

The Raspberry Pi SPI runs at APB clock speed, which is equivalent to core clock speed, 250 MHz. This can be divided by any even number from 2 to 65536 for the desired speed. The datasheet specifies that the divisor must be a power of two, but this is incorrect. Odd numbers are rounded down, and 0 (or 1) is equivalent to 65536. A divisor smaller than 2 is ...


14

Modprobe on Boot - Debian To answer the specific question about sudo modprobe snd_bcm2835, add the module to /etc/modules and reboot. (You will need to be root to do this.) Starting services - Debian Debian using initscripts to initialise the system, and you can use them to run arbitrary commands. You need to install a script similar to the following in /...


13

I have just installed this library successfully in Arch Linux. I can't see any reason why it wouldn't install in any distro. It's important to note that I do not have a Kinect, so I cannot verify that the library works, only that it compiles and installs successfully. Here are the steps I took: Install dependencies These packages are dependencies of the ...


10

Counldn't fix the problem, I guess the chipset is not really supported. Ordered an Ralink RT5370 from eBay for $5: Ralink RT5370 on eBay (It has working monitor mode)


8

Adafruit now even has a tutorial to connect the DHT22 to the pi. The example code works on most Pis, I had to tweak the C code a little like posted in the raspberrypi.org forums (increase a sleep timer). For other working sensors (including 1-wire and I²C) take a look at my blog. But e.g. the TMP102 is still missing in the list.


8

The Revision 2.0 of the model B Raspberry Pi has exposed the JTAG pins. See http://www.raspberrypi.org/archives/1929


8

The driver you need is in the repositories. pacman -Sy dkms-8192cu If you could get internet access temporarily, you could simply download and install it.


8

Turns out the steps to recompile and load the rtlwifi module are correct. The problem is iwconfig not working to enable/determine monitoring mode in this situation. Instead, I used iw as outlined by Steven Gordon and it worked. To summarize: STEP 6b: List the physical network interfaces available $ iw dev STEP 7: Determine if the physical interface ...


7

You can find a lot of informations here. Unfortunately, using JTAG on RPi is not straight forward. To be honest, just because it's so problematic, I didn't bother to get it working. Here's what I know, however: Not all JTAG signals are easily available. All but all are on GPIO connector (not on P2 JTAG connector - it's a VideoCore JTAG, not ARM and AFAIK it'...


7

PCSX-ReARMed should be already runnable on the Raspberry Pi. In this thread people says that it compiles fine but it's a little bit slow, still playable though. Here a couple of youtube videos that show the smoothness of two games: Crash Bandicoot and Dragon Ball GT Final Bout. As someone already said, now the Raspberry Pi is the cheapest Playstation ...


7

Indeed, it was a problem with the drivers. I switched to use Raspbian and then I installed the drivers, like explained here. Dowloaded the driver Extracted the files (tar xvf LCD-show.tar.gz) cd LCD-show/ sudo ./LCD35-show (this depends on the display size, mine is 3.5") In my case it didn't reboot automatically, but it displayed some messages regarding ...


7

One of the things that I have read a hundred times in dealing with anything attached to the USB on any model of RPi is to make sure that you have a decent Power Supply (2 or more Amps) or use a quality powered USB hub. Could it be possible that your WiFi dongle isn't getting enough power now because the HDMI screen is too greedy?


7

After hours of reading threads and following guides here and there, the definitive guide that got the driver working was here. Following the steps listed in that post: $ # install necessary software $ sudo apt-get update $ sudo apt-get install bc git $ # download raspbian kernel sources, takes some minutes $ sudo wget "https://raw.githubusercontent.com/...


6

According to the wiki, I2C is exposed on pins 3 (SDA) and 5 (SCL). Using from Python on Debian (Untested) Based on reading this forum post. Run sudo apt-get install python-smbus to install the drivers. At the time of writing, there is a test script here. Note: Someone needs to test this.


6

Edit: It's here! Check the release notes for NOOBS v1.3.3: Check out the release notes for each distribution for more details. Highlights for Raspbian include: New firmware and 3.10 kernel, with numerous functionality improvements. New hardware-accelerated X driver included and enabled by default. Mathematica and the Wolfram Language ...


6

If your idea is to make an exact carbon copy of the Pi 2, you won't succeed. While @joan stated that the OTP contents are not shared to the public, the actual SoC is also not available. The BCM2836 is a custom design for the Raspberry Pi Foundation and I doubt it is available through the common channels. That being said there is a wide variety of Raspberry-...


6

What is the difference between kernel "3.18.11" and "3.18.11-v7+"? The -v7+ is tacked on to indicate this isn't from a vanilla source tree, and that it was compiled specifically for the Pi 2. I'm planning to get this kernel source: wget https://github.com/raspberrypi/linux/archive/rpi-3.18.y.tar.gz Is this the correct source for my kernel? No. If you ...


6

Important: Follow these instructions meticulously Note: The OP is using Wheezy and the latest kernel version from raspberrypi-bootloader then is 4.1.7-v7+, while on jessie that version is 4.1.13-v7+ and that's a critical difference! If you're going to apply these steps to your own situation, adjust the values accordingly. Step 1: Get the git_hash from ...


5

I don't think you'll find a better resource than this unless you know somebody personally. Enjoy P.S. In case the link dies, the book is called Linux Device Drivers.


5

The SPI can be run at the core clock speed or divided down for slower peripherals. The core clock is 250 MHz. The divider can be set to any power of two - from 2^0 all the way up to 2^16. This means that SPI frequencies from 3.8 kHz to 250 MHz are supported. Sources: BCM2708 Linux drivers (line 208): .rate = 250000000, /* 250MHz */ https:/...


5

To update Krzysztof's great answer, Broadcom finally publicly released some code, licensed as 3-Clause BSD, to aid the making of an open source GPU driver. The "rpi-open-firmware" effort to replace the Raspberry Pi VPU firmware blob started in 2016: https://github.com/christinaa/rpi-open-firmware. See more at https://news.ycombinator.com/item?id=11703842 ...


5

A comment to goldilock's great post: Just wanted to add one thing I observe with rpi-4.1.y branch (05376fce25aaab4f47182a5af04928bfa06f30d6): In order to have USB working (this includes the USB-connected ethernet), one has to also enable BCM2708_MBOX (Device Drivers->Mailbox Hardware Support->Broadcom BCM2708 Mailbox (vcio)). Without this option USB starts ...


5

There should not be a driver problem with the 2.8" display and RPi 2 newer kernels, as support is built in (ie you don't need the adafruit kernel) 4.0.7 works. The main problem is with the touch screen support. I have the same set up (but kernel 4.0.9-v7+). To get the display to work, you need either the adafruit dts overlay file pitft28c-overlay.dts (which ...


4

I have tested with the as seen on http://www.brianhensley.net/2012/07/getting-spi-working-on-raspberry-pi.html and changed the speed. The maximum speed when the test passed is 15MHz = 15000KHz: See result: spi mode: 0 bits per word: 8 max speed: 15000000 Hz (15000 KHz) FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF ...


4

The datasheet of BCM2835 says the following on page 120: The value of the clock register of the SPI block contains. BC Clock Divider SCLK = Core Clock / CDIV If CDIV is set to 0, the divisor is 65536. The divisor must be a power of 2. Odd numbers rounded down. The maximum SPI clock rate is of the APB clock. I can't find any reference to what is ...


4

The Model B uses a SMSC LAN9512 USB 2.0 Hub and 10/100 Ethernet Controller IC to provide multiple physical USB host ports from the single USB OTG port available on the Broadcom SoC. The presence of this hub IC prevents the USB ports from being used in slave mode. However, as the Model A does not have this IC present and instead just has a single USB port ...


4

About "works with external power": This generally means that it has been tested with a USB hub that uses an external power supply. So the power needed for the devices connected to this USB hub is not extracted from the Raspberry Pi but from this external power supply. The Raspberry Pi can only provide around 140mA per USB port, while the USB specifications ...


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