I'm interested in which fingerprint scanner to use in a project with arduino or raspberry pi. This scanner MUST ONLY take the picture of the fingerprint and not to process neither validate the fingerprint because all of this will be done in a computer.
You can try an R305 module. It is one of the more popular modules with communication over UART. Adafruit has an existing library though it does not cover image download. However, there's substantial documentation that contains all the commands including the command for extracting the images you need. An image is usually a sort of compressed 256x288 grayscale BMP and is typically 37kB in size. You'll need to extrapolate to get the complete 74kB image. You should keep in mind that the maximum baud rate is 115200 or 11.5kB/s so it will take about 4 seconds to download an image before you can begin processing it. An Arduino would be unreliable at that baud rate too.
Another module that is completely compatible with the R305 is the FPM10 module; all the commands are the same and they are easily interchangeable. Here's a tutorial that can help.
Related
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 am amazing that arduino due has file operators.But where is my file?
I don't know what's the meaning of a file on a system without file system.
You need the 3V compatible shield which has SD card slot. You can also implement the host USB stack and connect usb storage devices. You can also create your file system in the uC FLASH. The last two require vast knowledge of the hardware as I do not think that you will be able to find the arduino libraries for it.
I have a project with a Arduino Uno where I need to store a char** that is too big for EPROM.
I am currently trying to do it with serial but I could also use a AVRISP programmer if needed (Not preferable)
So far I have looked into the avr/boot.h API but I am not really sure how to use it properly or if it is even the correct way to do it.
The arduino (specifically atmel 328 versions) only allow you to write to flash memory when the bootloader allows it.
The standard bootloader allows you to write to flash when a new program is being installed, but does not allow runtime programs to write to flash.
Solution: Install a bootloader that does allow you to run functions that enable you to write to flash.
Here is a bootloader (featured on hackaday) for an arduino that allows you to write to flash memory during runtime http://majek.mamy.to/en/writing-to-internal-flash-on-arduino/
Here is the hackaday post on the subject
https://hackaday.com/2015/07/03/arduinos-and-other-avrs-write-to-own-flash/
From the ATmega328P datasheet, "Boot Loader Support" section, "Application and Boot Loader Flash Sections" subsection, "Application Section" subsubsection:
... the SPM instruction is disabled when executed from the Application section.
Therefore there is no way to write to flash from the running program. Use an external memory device if you need to store more data than fits on-board.
I don't believe that's correct. The 328p does have the ability to control what some instructions about where they are allowed to access. I didn't see anywhere that this wasn't possible and in some configurations it (328p) can write flash under it's own control.
I searched the data sheet for 'SPM instruction is disabled' and hit only on the ATmega 48a/48pa. Having confused myself many times with that datasheet reading about the wrong controller. This didn't ring a bell.
Copied directly from the datasheet (660 pages):
"The ATmega 48A/48PA has no separate Boot Loader section, and the SPM instruction is enabled for the whole Flash if the SELFPRGEN fuse is programmed (“0”). Otherwise the SPM instruction is disabled."
The 328p has 'Lock Bit Byte' sets all of these controls, generally speaking.
These also control what access they have.
I would think you'd want to put it into eeprom (which IS different)...
Jack
Whenever I need to upload the bootloader to my Arduino Mega (ATMEGA2560) I use an AVRISP MKII with the fuses/lock bits described in boards.txt file. Doing this I am able to burn arduino sketches by serial connection with my FTDI.
My question is: is it possible to burn arduino sketches (.hex files) with the AVRISP but keeping the bootloader? Whenever I try to do that (I use the same avrdude command I use to program the bootloader but changing the bootloader .hex file to the sketch .hex file) I am no longer able to program the processor with FTDI (and then I need to program the bootloader again).
I think (of course I can be wrong) this problem occurs due to the fuse and lock bits settings that cannot be the same as those used to program the bootloader.
This is the fuse settings I use (from boards.txt file under Arduino folder)
mega2560.name=Arduino Mega 2560 or Mega ADK
mega2560.upload.protocol=wiring
mega2560.upload.maximum_size=258048
mega2560.upload.speed=115200
mega2560.bootloader.low_fuses=0xFF
mega2560.bootloader.high_fuses=0xD8
mega2560.bootloader.extended_fuses=0xFD
mega2560.bootloader.path=stk500v2
mega2560.bootloader.file=stk500boot_v2_mega2560.hex
mega2560.bootloader.unlock_bits=0x3F
mega2560.bootloader.lock_bits=0x0F
mega2560.build.mcu=atmega2560
mega2560.build.f_cpu=16000000L
mega2560.build.core=arduino
mega2560.build.variant=mega
Can you help me?
Thanks in advance.
Some controllers like the AT*X*MEGA series support individual flash sections that can be programmed/erased independently. However, with the ATMEGA2560 this is not possible.
One way would be to concatenate the .hex files as part of the build process. This can be achieved with some modifications to the makefile.
Something similar to this
all: $(TARGET).hex
srec_cat bootloader.hex -intel $(TARGET).hex -intel -o combined.hex -intel
Flashing the ´combined.hex´ would then include both, main application and boot loader. There is a related discussion on AVRFreaks.
Regarding the fuses, you just have to make sure that the boot loader (address) stays configured as the entry point.
EDIT: You can use this fuse bit calculator to verify fuse settings. Select your device and make sure "Boot Reset vector Enabled (default address=$0000); [BOOTRST=0]" is enabled with your current high fuse value.
You currently use
mega2560.bootloader.high_fuses=0xD8
so that seems fine.
I have a number of Windows 2000 systems that we are trying to use to program the new Arduino Uno and Mega devices. These boards now come with a USB connection, an upgrade from the prior FTDI. I'm not able to download the Arduino code into the board from a Windows 2000 system
The supplied drivers are *.inf files that modify the standard USB driver that comes with Windows (in this case Windows 2000).
I go through the process of setting the port, setting the device and doing the download. The download fails, and the apparent error is that the PC can not communicate with the board. I've checked the port, adjusted the baud rates, etc. I've even moved the port number from a high port number (ie COM12) to a lower port (COM2) without any success. I do see activity on the rec/xmt lights on the Arduino board, so some type of data is being sent and received.
I'm looking for:
Someone who has been able to download files from Windows 2000 to the Arduino
or
A way to shim inside the USB driver to be able to watch the traffic going up and down to the board so I can continue to debug this.
or
Some general tips for things to look at in the .inf file that need to be set/not set to make it work on Windows 2000.
I know the boards work I've used them on a different set of Windows XP systems. So I know to some extent the install is good and that most of what I have works.
Full dumps can be found on the Arduino forum, http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1291090110/.
This is the information produced by the AVRDude program while it's trying to download the code.
this could be a long shot, but I jsut recentlz had problems uploading too. Fist of all, how long is the USB cabele you are uploading from? Mine in one case was too long and th arduino woul lose sync. Secondly, and this might just be a silly oversight (like i did) do you have things wired in the digital pin 0 and 1? These are used for the communication, and if there is anything else plugged in to them the upload will also fail.
As I said, long shot but those were two errors I had.