Raspberry Pi Forums

thexeno

Thanks, I see on other places many are suggesting such book. that particulat chapter somehow is a good answer already. OT: developing a device driver for embedded linux requires to start from another book? I honestly think is not the case, as "embedded" means configuring the build of the kernel in a...

thexeno

Hi, For pure self-interest, being myself a firmware developer, I have a natural curiosity in seeing where the software gives "control" to the hardware. By that I mean where is located the ultimate instruction which makes an access to a register, or reads from it. What I am trying to understand is no...

thexeno

What I fear is that the board itself cannot do low power (even if SoC can sleep and wake up) because you even don't consider this when designing the board. Then of course this is all pointless. Not necessarily. With a HAT or something in between on the power USB, with a full hibernation all can be ...

thexeno

If adding sleep mode was fairly easy it would have been done years ago. It's very much a non-trivial problem, it may even be unsolvable. There's nothing from Brcm, they are not interested, so any support would have to be done by us, and at present we have no plans for any advanced sleep support - t...

thexeno

Something like this ? https://shop.pimoroni.com/products/fan-shim Very much so! That is not SMBus am I right? Because you can read the fan speed or do other sh*t by using only one I2C bus and on address. There is no SMBus on the Pi. Although SMBus is of course just a very specific implementation of...

thexeno

itsmedoofer wrote: ↑
Wed Jun 26, 2019 2:11 pm
Something like this ?

https://shop.pimoroni.com/products/fan-shim

Very much so!
That is not SMBus am I right? Because you can read the fan speed or do other sh*t by using only one I2C bus and on address.

thexeno

Hi, I read about the lack of support for the sleep mode. One may say that does not matter and dismiss the question like that, like many from the forum, but please don't do that. Not only is useless, but is like spam. So to me it does matter, or at least I am curious about, as first thing today is a ...

thexeno

Hi, I was looking around for an heatsink for the RaspberryPi 4, and I found something "bulky" like this: https://shop.pimoroni.com/products/raspberry-pi-4-heatsink Would be maningful to have instead just a fan, maybe SMBus controlled, to smoothly working only when needed? I wonder if exist something...

thexeno

Hi, I want to experiment few things with python and using all the updated software, with the latest Raspbian. I have an old Raspberry Pi Model A (you still remember? with 26 pin header and 256MB of RAM, composite video output, and 32 miserable bits CPU?). To be practical with my project, I should go...

thexeno

I saw what I can do with OpenVPN. I want to use uniquely an address define with no-ip.org and use a web page or application like FileZilla to exchange safely files, without sharing the content of the Pi. For now the best and EASY solution seems to be the one on which I started, SFTP. Could be? I don...

thexeno

I considered this and is the best option to use it remotely. But can I make visible only one folder for a determined set of users?

thexeno

Ok, I followed this path. But I have some problems. I report wverything so you can emulate the issue. In /etc/ssh/sshd_config i've put: where the group nas contains the user nasaccess SubSystem nas internal-sftp Match Group nas ChrootDirectory %h ForceCommand internal-sftp AllowTcpForwarding no then...

thexeno

Hi! I'm not sure if it is the right place, but I try. In my LAN I've setup my raspberry to be some sort of NAS, accessing to it with samba in my network. I'd like to to the same over the internet, but just sharing a defined folder like with Samba, and I'd like not doing so without knowing what I am ...

thexeno

All I/O of the BCM2835 are compliant with the standards. Well, there are things that could differ from 3V3 to 3V3 cmos. But, I understood. Anyway, the improvement suggestion has been done, I tried at least. I think http://www.scribd.com/doc/101830961/GPIO-Pads-Control2 is the nearest there is (curr...

thexeno

I think that if you send 2 set inf instructions through USART, you can connect a device 1, then "snooping" the bus the device 2. BUT The first (or second) parameter shuld be an address that activate the response of the device dsired. The second yout data. §But the protocol is up to you, and I thinks...

thexeno

the RPi GPIO runs at 3.3V see http://elinux.org/RPi_Low-level_peripherals#General_Purpose_Input.2FOutput_.28GPIO.29 [older not mentioning b+] you max current draw is 50mA total , and 16mA for any one pin I already know that, but thanks for effort of course. But is not detailed, like, to do a refere...

thexeno

The characteristics of *board* are widely publicized: 5v at 700mA. Since you're buying a board and not just a BCM2835, why would the specifics of the BCM2835 matter to you? It should be trivial that the GPIOs are connected to BCM, whichever the board. You can understand that current and voltages mu...

thexeno

Yeah, thanks, you got my point. I opened this thread after reading that site: because they say something about some datasheet, but I didn't find nothing about that. For sure their reports are coherent. Like the "officiality" of the missing of full datasheet/videocore infos, despite it is not a thing...

thexeno

Where can I find the electrical charactristics of the BCM ports? I've found, only barely mentioned, something about the Vil and Voh and nothing more, or maybe on the current. Otherwise some of my projects can not ad affordable as I want to design them. I just stepped in a problem of minumum voltage ...

thexeno

Thank you ALL. I understood almost everything of what I'm looking for. For other problems related to these devices under the OS, I should probably refer to the bare metal programming or similar, sections discovered recently (I know, I know...) Just to ask, @Dom, are you working for the Foundation? I...

thexeno

- Start.elf initialises most of the chip, sets up the clocks, loads a kernel image (if any) and powers on various bits and pieces. Start.elf also contains the GPU code that presents the MMAL/OMX/mailbox interfaces and also does most of the OpenGLES work. and also USART, to be able to set the parame...

thexeno

The PL011 UART (uart0) is currently initialised (baud rate divisor and GPIO pin settings) by the GPU bootloader prior to loading the ARM kernel image. The kernel image knows about this UART ahead of time and can start spitting messages out immediately. That is exactly what I'm talking about. I supp...

thexeno

Thank you. But I'm not sure that is initialised by those files, at least in the way that I mean. Now I'm try to explain: I say you this because: I see the initialisation of a peripheral (i.e. USART) with some characteristics (baud, folder location ecc) inside those files, but not the hardware init, ...

thexeno

Recently, I started to use some serial functionalities of my Rasp. Searching here and there, I also noticed the capability to log on serial the terminal on booting phase (I know, I didn't know that before). So, a question in my mind arise: speaking about linux console parsed to serial during the boo...

thexeno

kahlenberg wrote:Very cool idea ! and don't forget cooling fans since there is no air in the space to blow the heat away

A fan to blow (with air) the heat away, because there is no air. Sorry, but lol

Search found 75 matches

Re: How the OS makes access to hardware registers

How the OS makes access to hardware registers

Re: (again) Raspberry Pi sleep/standby modes software support

Re: (again) Raspberry Pi sleep/standby modes software support

Re: RaspberryPi 4: heatsink or fan

Re: RaspberryPi 4: heatsink or fan

(again) Raspberry Pi sleep/standby modes software support

RaspberryPi 4: heatsink or fan

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Re: Safe NAS over the internet

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Safe NAS over the internet

Re: Electrical specifications BCM2835

Re: One UART two serial devices and one cheap hacker

Re: Electrical specifications BCM2835

Re: Electrical specifications BCM2835

Re: Electrical specifications BCM2835

Electrical specifications BCM2835

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Re: USART hw initialization

Re: USART hw initialization

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