I have successfully talked to the computer from an Arduino via serial USB port and I had the idea that I could make a keyboard or mouse with the arduino. Say I wanted to translate the computer's mouse 1 pixel to the left. What message would I have to send over the serial line in order to achieve this?
Google is a wonderful thing. "use arduino as mouse" returns 1.7 million hits. The third hit on the list takes you to the Arduino Playground for an example using the new Leonardo board.
Note:
The Leonardo differs from all preceding boards in that the ATmega32u4 has built-in USB communication, eliminating the need for a secondary processor. This allows the Leonardo to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.
Assuming you don't have that board, here is another site for some other specific boards and yet another that is log for a project including hardware and software for older boards.
Hope this helps (and is a better answer to the question).
You would have to reconfigure the USB interface chip to appear as a USB HID endpoint.
Related
I am trying to learn Linux by following instructions in "Mastering Embedded Linux Programming" by Chris Simmonds. By following the book and with some help from Stack_Overflow_1, i was able to build the MLO and u-boot.img.
However, when i connect USB cable to my PC and execute the ls /dev/tty* command, i cannot find any device with /dev/ttyUSB. All i can see are devices with /dev/tty0-63, /dev/ttyS0-31 and one /dev/ttyprintk.
Also, when i press down the S2 button and connect the USB cable, i can only see the power led glowing and nothing else.
I have properly built the u-boot (three attempts to get it right).
Also, as per the instructions in the book, i am only testing the u-boot stuff and yet to reach the kernal part.
If i remove the sd card and connect the USB, im an able to talk to my BBB over ssh (192.168.7.2).
How to i get the u-boot to work? Thank you!
If you don't have one yet, I'd recommend to get a USB-to-serial device (3.3V Vref). You connect it to the debug UART (J1) which is located next to the P9 side. Nowadays those are very cheap and can cost below 1$. Ones that feature a genuine FTDI part will be 5-10$ at least.
The serial port you are referencing is only available once the device has passed through U-Boot, booted the kernel and finally userspace has set up the communications.
Especially when working with U-Boot and the Kernel, low level UART access is crucial.
As a further note, could it be that the Book refers to the (white) original Beaglebone? That has a FTDI USB-to-UART chip on board and will allow you even U-Boot access. You can do the same things if you have the above mentioned USB device.
https://groups.google.com/g/beagleboard/c/eNDjK05spY8/m/GPvhcP52BAAJ shows that one needs to hold the space key to enter u-boot.
Also, the info. here might be more up to date compared to the book.
https://www.digikey.com/eewiki/display/linuxonarm/BeagleBone+Black
There is no way to copy and paste everything from the eewiki. I just left you the link. Enjoy!
I am very new to C and embedded programming.
I simply want to have my main thread wait until a usb device has been plugged in to my embedded device.
However, no matter how hard I look, I cant find documentation or examples about how to check if the usb has been plugged in.
I am using a ATSAM4S8B.
EDIT:
Actually I think the usb capabilities are built into the chip, I can use Atmel ASF libraries.
I am hoping that there is just a library function I can call to see if the usb has been connected too but I can't find anything like it.
There are two ways of detecting USB connection:
waiting for usb events occure and special USB flags to fire in hardware registers, which will signal if initiating process started. This solution depends on a particular chip you use and firmware burnt into MCU.
use sense IO pin. Attach USB 5V through 1k resistor to a pin of the MCU. High level on the pin will indicate, that USB was connected. Dont forget to use high value (>10k) pull-down resistor, which will pull the input low when USB disconnected.
i have a portable device that consist of
arduino leonardo board,xbee series 2 as router( AT mode ) and different sensors.This portable device acts as a remote device and can be used upon power up.
The other side, i have a host controller that consist of arduino uno board, arduinoxbee shield v1.1, and xbee series 2 as coordinator( AT mode ). This host controller is plug through USB into my PC.
The aim of my project is to send the sensor data from the portable device using xbee wirelessly over to my host controller and displaying out on the arduino serial monitor.
I've managed to configured the two xbees. But now, i'm unsure of how im going to transmit and receive the data. I need a transmitter and receiver program for both xbees that is connected to the arduino. Anyone can help please?
There are a couple different options for how you can do this, but the simplest is to set up your sensor XBee either in change detect (IC) mode, or set a sample rate (IR). In either case you'll need to handle the RX Indicator frame at the controller, which will contain the sampled data.
I wrote a C# stack that can configure all this, but for what you're trying to do it would probably only be useful as a reference (https://github.com/jefffhaynes/XBee).
Non-programmable Xbee modules should be configured through a PC (with XCTU) or other devices like Arduino... but can the programmable xbee modules (like xbee-pro zb s2b) autoconfigure themselves, without being connected to another device like a PC or Arduino, by running code stored in their memory?
I mean, can they run orders like the ones you run through XCTU but programming them in the internal memory code? Like scan energy of every channel, select a channel, set a PAN ID, configure the different parameters of the device...
Thank you
Yes, the development kit includes an API for sending AT commands from the co-processor to the radio on those boards.
There's also a passthrough mode that relays the host computer serial port through to the radio processor, which can help with initial setup/configuration of the modules like you might do during manufacturing.
To answer your question:
I mean, can they run orders like the ones you run through XCTU but programming them in the internal memory code?
No. You can not program a sequence of orders/commands into the internal memory of the device. To do anything meaningful the device needs to be "driven" from a host PC or MCU that can send the AT Commands.
If you want 1 device solution that does not require a Host MCU then you will need to use a ZigBee SoC (System on Chip), such as the CC2538 - http://www.ti.com/product/cc2538 running a ZgBee SDK (Software Development Kit) - http://www.ti.com/tool/z-stack (ZStack-Home). However this will require you to develop the ZigBee application SW.
Regards,
TC.
I don't have much konwledge in electronics. i wanted to turn on/off led connected to usb port using program. usb port consists 4 line (data+,data-,voltage ,ground) if i connect voltage and ground lines to led , it will glow. i've been searching on internet this issue and i find that it is not possible to control led connected to usb using program because supply over datapin is too low which can not be used to tun on off led.
but what if i connect my led to vol and ground pin and control the entire power supply of usb port , i guess it is possible to control led using program. there is a way to disable and enable power supply over usb port.
i also want to know is it bad to follow this approach. does it damage usb controller to frequently enable/disable power supply.
Algo :
a = Get_input_from_user() ;
if(a=="ON")
turn power supply of usb port ON.
else
turn power supply of usb port OFF.
this thing is certainly possible using extra hardwares, i don't want to use any extra hardware.
The power for a computer's USB ports is generally not software controllable. In most cases, the power pins of your USB ports are wired directly to the 5V rail of your power supply (usually through a polyfuse), so there is no way to switch them on and off.
Some powered USB hubs do support switching power to their ports, but you said that you didn't want to use any extra hardware, so you're out of luck.
you can use any basic Arduino board to do this there is a complete IDE free and a LOT of sample code that will do what you want out of the box
you can also use a COOL board.
Arduino Compatible code is available for the Teensy
Software Development Tools HERE
You can use an external power supply (the Vcc and GND pins of the USB port in this case) with a resistor to power the diode and connect a transistor in the middle working as interruptor. Then, yo connect the base and emisor to de data+ and data- of the USB port.
this page doesnt let me upload images.
Sorry for the quality of the drawing but all I have on the computer is paint.
For a more stable performance make sure to make R1 low enough so that transistor is on saturation mode when data pins are ON but not so low that transistor gets burnt (I dont really know what is the voltage level of the data pins on the USB port, sorry).
To choose a proper value of R2, you need to know the current you need to power your diode. It's calculated acording to Ohm law:
Idiode = (Vcc - Vce,sat - Vd) / R2.
Where Vce,sat is potencial diference between colector and emisor when transistor is on saturation mode (it is found on the transistor datasheet on the manufacturer webpage, usually around 0.2V) and Vd is the normalized potencial difference of the diode (the same, but this time around 0.6V).
Note that data- and GND pins are connected. I am 99% sure that this won't harm your USB port, but use it at your own risk.
I would test it out using another external power source first anyways, just to make sure you connected everything properly.