I am trying to send/receive data over serial connection (GPIO UART pins) between a Raspberry Pi (B model, raspian wheezy) and any pc (tried a netbook and desktop, both running with win 7).
I followed all the stepts found in several tutorials like: http://codeandlife.com/2012/07/01/raspberry-pi-serial-console-with-max3232cpe/
to build a 5V to 3.3V converter. (unfortunately i can't post a pic yet)
The settings for ttyAMA0 in files 'cmdline' and 'inittab' are ok. (like described in many tutorials)
Connecting RX/TX on rpi direct works fine, so i can send text over GPIO pins and receive it. But as i connect it to a pc there is no way to read or write any data. Baudrate 9600 or 115200 doens't matter. (Hardware connection: rpi GPIO -> voltage converter -> serial USB adapter -> pc)
On pc i used Putty. On the rpi:
'echo text >> /dev/ttyAMA0' on the terminal
Putty and
minicom
but no one had success
Is there anything i missed? Could you give me some advice i could look for please.
some ideas:
Whereever i plug the usb into one of 3 available netbook USB ports the win device manager always say it's on COM3... shouldn't it change?
is there a possibility to make some measurements inside the voltage converter wiring to insure that it's not a broken component in the hardware circuit? (i have no knowlegde of it's function)
Related
A method to Connect / Disconnect a USB device "softly".
Hey, Assume I have a USB device connected to my PC, I want to enable/disable the port it is connected via computer so that I don't have to unplug/plug my device each time.
P.S : Device is a Microcontroller Board ( powered by USB port ) , so I don't want it to be active all the time. I want to deactivate it when appyling changes to code etc. and then activate that port so I can load my code into it again.
Is there a method to do so ?
Thanks in advance.
Device is a Microcontroller Board ( powered by USB port )
Most USB enabled µC types can "unplug" themself.
The idea is to put the USB data pins (usually called D+ and D-) into "output low" state for about one second at startup. This forces USB to be recognized as "disconnected".
After that is done, re-configure the pins to for their USB function and initialze the USB as usual.
Note that this method is not possible on old style boards that still use USB2UART chips instead of hardware USB inside the µC itself.
I currently have a sensor attached to a USB to RS485 Serial converter cable which is plugged in to a raspberry pi. I've tried using the ftdi d2xx drivers to connect to it, but so far I can't read any data and while the writes don't fail, I'm not sure they're working.
This setup works on Windows with the custom software provided by the manufacturer, but I can't find anything on getting it to work on a linux system. Is this possible?
I have a 20 year old device that prints data through a 1994 HP Deskjet 550c printer using a parallel port. Now the printer is broken and so there's no way to view the device output. I was thinking of hooking the parallel port from the device to a Raspberry Pi 3 which will display the data on a computer screen. I can get a parallel to USB cable which connects the old device to the Raspberry Pi. When I press the print button on the device, data should be sent to the Pi, but what I'm worried about is the format of the data. Is there a standard protocol for print data, or does every printer manufacturer use their own protocol? Do you know of any open sourced python scripts that can directly parse the print data coming from the usb port? Do I need to install any drivers on the Pi?
I am developing a project using Arduino to send a message to Raspberry Pi using an APC220 Radio Communication Module.
The Raspberry Pi can't receive serial message by using USB connect to APC220. I want to know how to use APC220 in Raspberry Pi?
The APC220 has a TTL UART interface which you can connect directly to the RPi TTL UART pins on the GPIO header - you do not need the USB-Serial converter (though that should work too if it is a standard CDC/ACM device - though this suggests that there may be issues).
A note of caution however, the RPi GPIO pins use 3.3Volt logic, the APC220 datasheet is not clear on the TTL level used, but the specified supply range is 3.3 to 5.5 volts so it seems likely that it is 3.3V - best measure it to be certain. You can probably use the RPi GPIO headers's 3.3V supply pin to power the ACM220, then you will be sure to be safe. If the ACM220 level is too high, the quick-and-dirty solution is to use current limiting resistors in-line to protect the RPi (10KOhm should be enough, but don't hold me responsible; you should know what you are doing before proceeding).
The UART device on the Pi is /dev/ttyAMA0.
See here for details of serial I/O on the Pi.
22 Feb 2012 Update
The discussion here suggests that to make the TTL<->USB adapter work on Raspberry Pi, you need to disconnect the EN signal - the discussion links back to the manufacturer documentation, which gives that advice in the troubleshooting section. Since that makes the device appear as a USB serial, and you won't have to reconfigure the on-chip serial or build a connector that may be simpler.
I have Firmata working fine on an Arduino Uno, communicating over cable USB to Processing.
I want to get rid of the cable, and run the connection over Bluetooth transport (with a BlueSMIRF module). I am unclear on what I need to do to Firmata to tell it to use the BT module rather than the (unconnected) USB cable interface. In particular, do I need to hack Firmata itself to add initialization code which is
specific to the BT module I'm using, or
more generally, needed to tell Firmata to use a port other than the cabled USB?
Thanks
D
I am NOT very good in Firmata, but as i know, Firmata (on arduino) uses 'Serial' (pin 0 and 1, also aka as TX,RX) to communication with the Host. So, if u want to use a BT module to replace your USB cable on the arduino, hack the Firmata to use other pins, other connect the BT to pin 0 and 1.
You have to upload standard firmata with baud rate changed to 9600 inside the ino file (or test with other speed rate) and then connect BTooth TX>Rx(uno RX) and the bt RX>Tx(uno TX) as said in the previous post ,testing it with arduinoCommander worked like a charm!Arduino uno rx tx are pin0 and pin 1.also have it powered not from usb pc but external source cause having the BT ontop while on usb could mess up thing (in general disconnect the ground from BT module while uploading sketches).
All you have to do is make sure the USB is connected only when you are uploading your sketches to the arduino and then have the BlueSMIRF connected when you are ready to actually run the Arduino code. This way they will both use the default hardware serial port and you should not have to modify any code.
You could try and use SoftwareSerial.h in the Arduino to emulate another serial port but I have found that to be problematic.
Just connect Bluetooth to the Rx Tx pin and upload same standard firmata. Then pass command over bluetooth which you were passing over usb cable....it wil work.