I am supposed to demonstrate a scenario with and without encrypting RAM memory in Raspberry Pi. First of all, I want to know whether it is possible to encrypt RAM in Raspberry Pi. I tried googling about this but this topic seems to vague and ends up about Disk encryption.
Can someone give me any pointers about this. Any help is appreciated.
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So, I'm currently building an 8-Bit computer, and working on getting it connected to the internet, clearly just on a simple LAN to start off, in the hope of making ARP requests and such like which would be pretty cool.
I have had a little look around and I can only find standards companies selling MAC address by the million, this wont work for me.
Does anyone know how someone can accquire a single MAC address for personal use, not making money from it, but registered non the less.
Cheers all!
Well one idea is that Microchip sells small EEPROM memory chips preprogrammed with a MAC address. One example of this is the AT24MAC602. It also contains a unique read-only 128-bit serial number and 2Kb (256 bytes) of user-accessible serial EEPROM NVM storage.
One way to use this would be to incorporate the chip into your design. Another would be to read out the MAC with an appropriate reader and hard code the address into your project.
Can I use a RaspberryPi OR other device for all my inputs remotely and then send that data to be used in a calculation on a desktop and then send an answer back to the raspberry pi?
This is an idea for my prject.
This is a bit difficult to answer without a lot more detail, such as the sensors you are using and what you are looking to do with the data. I'm guessing you are reading a sensor using GPIO pins, doing a calculation on another computer, and then doing something with whatever is calculated on the RPi again?
The short answer is you probably can, but remember that the Raspberry Pi is very capable and you may be able to do the computation on your data locally on the Pi itself. If you are processing the data with python or uploading it to a server you should be able to do that all from the Pi.
If you truly need to do something with the data on a separate system, I would look into using an Arduino microcontroller of some sorts instead. A wifi-enabled build (such as the popular ESP-8266 variants) will be able to quickly read sensor data without the overhead of running a full OS, while still being able to transmit wireless to your computer. There are also countless resources and tutorials for doing so that you can access to help there.
If you are set on using the Pi, or are just more comfortable using it, then there are tons or resources for how to transit data from your sensors including plenty of Stack Overflow questions such as this one
I've been trying to establish serial (UART) communication between a Raspberry Pi Model B Revision 2.0 (checked the model like described on this page) and Arduino Mega 2560. I made a service on the Pi that writes to UART and then expects a message and a coworker programmed the Arduino with an echo program. While they were communicating, I had trouble receiving data, meaning that it was clustered in 8 byte pieces and I had to introduce a timeout for waiting between them (I was actually as much as available and calling select()for the next cluster but it turned to be 8bytes a cluster, except for maybe the last one. As explained in a question I found on this site, the programmer is the one to take care of the protocol and can not rely that the whole message will be ready to read at once (that is logical).
However, when I just connected Pi's TXD and RXD pins, no matter how much bytes I tried sending, it sends them in one go (I've gone up to a bit more than 256, that's more than enough for my purposes). I also have around 50 milliseconds of duration difference, measured directly from within the program, using gettimeofday() function.
So, could anybody clear things for me:
Why is this happening?
Is this difference in behaviour expected?
Is there a potential problem in either of the devices (if that can even be concluded from the given information).
Of course, any additional information is welcome, in case I forgot asking something that is deemed important.
Why is this happening?
I tried some time back communicating Arduino-Arduino and Arduino-Pi. I faced some problems with UART communication. However, you might want to keep same Baud rate on both the devices. With Pi, you might need to trigger an event if you receive data from Arduino. On the other side, if you code runs longer, then you might lose some data i.e. your Arduino code is running something else while Pi sends data over UART.
Is this difference in behaviour expected?
Yes. Arduino is a microcontroller based device while Pi is microprocessor based (runs on OS)
Is there a potential problem in either of the devices (if that can even be concluded from the given information).
I don't think there could be any hardware problem unless it is not functioning at all.
Also, because of this issues, I switched from UART communication to SPI communication. This solved my problem completely.
I am currently working on a system (home projects - finally got the time yay!) and i am wondering whether it would be possible to program an arduino from a pic32? the system currently has both and given the pic32 proc has an SD card attached, i figured i could use the platform potentially to program all the other systems if there was new firmware deployed onto the SD card..
just wondered if it was possible? there doesnt seem to be anything online but maybe im googling the wrong thing? i suppose the pic32 would be acting as an ISP?
Thanks in advance..
Chris
sure, why not, it is just spi. I think just out of convenience (of something with spi on it or trivial to bit bang) I use another microcontroller to program my avr (an msp430 or mbed which program easily over usb). avrs docs are pretty good on the protocol. you can use the serial bootloader as well, but that gets into a larger number of combinations of which arduino, what speed the uart is, exactly how and you have to tickle the dtr (reset), seemed like when I was still messing with that each arduino board type was different. Where with the isp interface excluding xmega, there are chip to chip differences as far as the identification number, etc but easier come up with something more generic. And the nice thing about that spi interface is the processor is in reset so you are not relying on there being a bootloader, what version of the bootloader, or a chip with a flash that is for some reason causing a hang, etc. you should generally get the same programming experience independent as to what was programmed before.
I just got an old pentium 4 and I thought, that it would be nice to calculate some heavy maths with it.
So I have a arduino duemilanove and I know, that how To send data in to the processor, but I dont know how I specify to processor that what mathematical things it should do (like multiplication, sqrt, sin and so on), and how do I specify that where do I get those answers out of the processor.
You make an application that you download into Arduino duemilanove and you make an application for your Pentium 4 computer. These applications need to exchange data via some communication channel like existing USB/FTDI/RS232. You need to learn how to send/receive data to/from it in both Arduino programming language and your favorite PC programming language. Then you need to make a protocol that both part will understand. Arduino will send a message that will include all inputs needed for computation, and PC will reply with a computation result. You will also need to learn how to download application to Arduino, and many other things on this way, but I strongly advice you to start with blinking leds. That's a hello world application for microcontrollers and every newbie should start with this little step first.
I think, that I gonna build a kernel to drive the basic functions of the processor, and I use agtl converted to ttl for arduino/cpu communication.