Node-RED read Serial status - node.js

My flow have 1 input node (Serial).
Phisically, in this Serial, I can connect difference type of device (printer, keyboard ecc...).
When I connect a device in the serial port, Node-RED recognize it and switch the node status from "not-connected" to "connected".
There is any way to obtain this status (connected/not connected) in a variable to use it?
I have try to check "msg.status" variable but there is no information inside...

Solve it!
Just use the "status" node in the input table and configure it.

Related

zbus connection not displayed in busctl list

I'm using the zbus crate to make a server able to get events from the dbus.
It works well my code (basically the same as the example from the documentation) is able to receive events so it's fine.
I use busctl to send an event like in the example:
busctl --user call org.zbus.MyGreeter /org/zbus/MyGreeter org.zbus.MyGreeter1 SayHello s "Maria"
And my code is able to receive the event with the parameter just fine.
The thing is I'm having some issues with udev and while I was trying to fix it I found some weird things:
If I send an event with another user it fails with Call failed: the name org.zbus.MyGreeter was not provided by any .service files while my program is running
When I do busctl list --acquired I don't see org.zbus.MyGreeter in the result
My question is: is it normal my program does not appear in the busctl list? Am I doing something wrong or do I use the wrong library to do what I want to do?
Ok it seems there are 2 busses and I was not using the system bus.
I had to replace the method session to system to indicates I want my program to run on the system bus.
Like this:
let _ = ConnectionBuilder::system()?
.name("org.zbus.MyGreeter")?
.serve_at("/org/zbus/MyGreeter", greeter)?
.build()
.await?;
Doing this is not enough because my program does not have to permission to create a service on the bus system. So I had to create a file in /usr/share/dbus-1/system.d where I did write the configuration needed.

libudev udev_device_get_sysattr_value() return NULL for idVendor/idProduct when device is removed

I'm trying to implement USB monitor service/daemon to detect specfic PID/VID device only. I can easily detect device 'add' action attrib by filtering PID/VID but when I remove ANY USB device from port then as part of 'remove' action attrib, I try to filter PID/VID same like in 'add' action ... by using
const char* vendor = udev_device_get_sysattr_value(dev, "idVendor");
const char* product = udev_device_get_sysattr_value(dev, "idProduct");
but in above two char ptr I always get NULL.
Due to this my remove action will execute for all USB device which will remove from port
Is their any other way in libudev API to detect specific device remove only ?
Once the USB device is at the "remove" action, udev_device_get_sysattr_value(dev) will return NULL in my experience. Even the prior "unbind" action is too late.
One way to detect the removal of a specific device is to store its dev node when it is inserted.
First, find the udev_device* you want to monitor by enumerating the devices (struct udev_enumerate*)(device already plugged in) and monitoring the "add" or "bind" action.
In those states, the udev_device_get_sysattr_value will return the correct strings as you have already seen. If the values match the ones for the device you want to monitor, retrieve its current dev node by calling udev_device_get_devnode(dev). Store that dev node value (strdup to make a copy of it).
In the "unbind" or "remove" action, udev_device_get_devnode(dev) will still return the proper value as opposed to udev_device_get_sysattr_value(dev, prop_name). Match the dev_node with the previously stored dev node to identify that the action applies to the device you are monitoring.
Note that the dev node will likely change every time the device is inserted.

ONVIF PullMessages Fault

I understand that cameras that do not have WSBaseNotification feature do not support push-style notifications (Notify), so I have to do the pull-style way (CreatePullPointSubscription and PullMessages).
First I obtain the SubscriptionReference address from CreatePullPointSubscription and pass it to the "To" address in PullMessages. This has succeeded with one of the three cameras I have tested but failed with the other.
Here is a sample of response for CreatePullPointSubscription:
<SOAP-ENV:Header><wsa5:MessageID>urn:uuid:18764990-3fd8-4175-b074-bfdd6816d5a2</
wsa5:MessageID><wsa5:RelatesTo>urn:uuid:1adbe268-c822-eb58-8560-b07639671351</wsa5:RelatesTo><wsa5:To SOAP-
ENV:mustUnderstand="true">http://www.w3.org/2005/08/addressing/anonymous</wsa5:To><wsa5:Action SOAP-
ENV:mustUnderstand="true">http://www.onvif.org/ver10/events/wsdl/EventPortType/
CreatePullPointSubscriptionResponse</wsa5:Action></SOAP-ENV:Header><SOAP-
ENV:Body><tev:CreatePullPointSubscriptionResponse><tev:SubscriptionReference><wsa5:Address>http://172.22.22.35:80/
onvif/device_service?Idx=0</wsa5:Address></tev:SubscriptionReference><wsnt:CurrentTime>2015-11-26T17:05:55Z</
wsnt:CurrentTime><wsnt:TerminationTime>2038-01-19T03:14:07Z</wsnt:TerminationTime></
tev:CreatePullPointSubscriptionResponse></SOAP-ENV:Body></SOAP-ENV:Envelope>
And PulMessagesRequest:
<s:Header><wsa:To>http://172.22.22.35:80/onvi /device_service?Idx=0</wsa:To><wsse:Security><wsse:UsernameToken>
<wsse:Username>admin</wsse:Username><wsse:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-
profile-1.0#PasswordDigest">XWhDcuw3cztspGCLlpQfVaqM1mU=</wsse:Password><wsse:Nonce>NTY1NmNiODFjYTk4MWZlNjFmNDA=</wsse:Nonce>
<wsu:Created>2015-11-26T09:06:09Z</wsu:Created></wsse:UsernameToken></wsse:Security></s:Header><s:Body><tev:PullMessages>
<tev:Timeout>PT5S</tev:Timeout><tev:MessageLimit>2</tev:MessageLimit></tev:PullMessages></s:Body></s:Envelope>
And PullMessagesResponse:
<SOAP-ENV:Header><wsa5:To SOAP-ENV:mustUnderstand="true">http://172.22.22.35:80/onvif
/device_service?Idx=0</wsa5:To></SOAP-ENV:Header><SOAP-ENV:Body><SOAP-ENV:Fault><SOAP-ENV:Code><SOAP-ENV:Value>SOAP-ENV:Sender</SOAP-ENV:Value>
<SOAP-ENV:Subcode><SOAP-ENV:Value>InvalidArgVal</SOAP-ENV:Value></SOAP-ENV:Subcode></SOAP-ENV:Code><SOAP-ENV:Reason><SOAP-ENV:Text
xml:lang="en">InvalidArgVal</SOAP-ENV:Text></SOAP-ENV:Reason><SOAP-
ENV:Detail>There is no subscribe.</SOAP-ENV:Detail></SOAP-ENV:Fault></SOAP-ENV:Body></SOAP-ENV:Envelope>
From the ONVIF core specs:
9.1.2 Pull messages
The device shall provide the following PullMessages command for all SubscriptionManager endpoints returned by the CreatePullPointSubscription command.
Therefore you need to pull the messages from the address returned int the CreatePullPointSubscription . Populating the wsa5:To field in the body of the request but using the URL of the event service is in general not enough.
You posted only the body of the soap requests and not the head, thus it's impossible to check the URL you're using.

App Inventor 2: Not finding a specific block

In the App Inventor 2, where is the block mentioned in last item (figure) of the url: http://beta.appinventor.mit.edu/learn/reference/blocks/definition.html
I am trying to use bluetooth to connect my custom device with Android App.
The internet says:
This block provides a "dummy socket" for fitting a block that has a
plug on its left into a place where there is no socket, such as one of
the sequence of blocks in the do part of a procedure or an if block.
The block you fit in will be run, but its returned result will be
ignored. This can be useful if you define a procedure that returns a
result, but want to call it in a context that does not accept a
result.
You are looking for the evaluate but ignore result block
However in your bluetooth connecting example let me recommend you to use an if statement instead
if BluetoothClient1.connect ...
then do something
else display a message, e.g. "connection was not successful"
see also this bluetooth example
and see the documentation of the Bluetooth components
boolean Connect(text address)
Connect to the Bluetooth device with the specified address and the Serial Port Profile (SPP).
Returns true if the connection was successful.

Execute AT commands in J2ME

I want to know how to execute AT commands inside a J2ME application. The approach that I am taking in brief is as below:
First get all the ports that are present in the phone by
String ports = System.getProperty("microedition.commports");
Now just try to write "AT" and wait for the response from each port (YES I said EACH!!!)
try{
commConnection = (CommConnection) Connector.open("comm:" + portsArr[i] + ";baudrate=19200");
} catch (IOException e) {
print("IOException:Port:" + portsArr[i] + "~Mess: " + e.getMessage());
}
Once I get an "OK" from some port I can execute my intended commands in the same way.
I am trying to execute this on two diffrent phones
Nokia SuperNova 7210
ports=USB1
When I try to write to the port nothing happens.
Nokia Xpress music
ports= USB2,COM1,IR1,USB1,BT1,BT2,BT3,BT4,BT5,BT6,BT7,BT8,BT9,BT10,BT11,BT12,BT13,BT14,BT15,BT16,BT17,BT18,BT19,BT20,BT21,BT22,BT23,BT24,BT25,BT26,BT27,BT28,BT29,BT30,BT31,BT32,BT33,BT34,BT35,BT36,BT37,BT38,BT39,BT40,BT41,BT42,BT43,BT44,BT45,BT46,BT47,BT48,BT49,BT50,BT51,BT52,BT53,BT54,BT55,BT56,BT57,BT58,BT59,BT60,BT61,BT62,BT63,BT64
When I try to write to USB2,COM1,BT1 port
IOException:Port:COM1~Mess: SymbianOS error = -1 : General:
System error
IOException:Port:USB1~Mess: SymbianOS error = -21 : General:
System error
IOException:Port:BT1~Mess: SymbianOS error = -44 : General:
System error
Is this a correct approach?
Smslib uses AT commands but I'm not understanding how do they execute AT commands or how they get the port on which to write the AT commands?
If not possible with J2ME I don't mind not writing the execution of AT commands in some other language as long as both are able to communicate and the solution will support a most of the vendors.
Related - https://stackoverflow.com/questions/3803508/can-i-use-at-commands-insider-j2me-app
What you are trying to achieve is absolutely not possible.
Your approach would only work if Java ME provided access to the GSM modem via COMM ports, which it does not!
(I suppose there could possibly be a device somewhere which offers this, anything's possible in Java ME land, but I have never seen or heard of this).
The library you are referring to runs on a PC which has a device connected to it via the COMM port, it does not work in a Java ME context.
I suspect that what you're really trying to do is access the handset's native SMS inbox via a MIDlet. I promise you, there is absolutely no way to do this!
If what you are trying to do is just send an SMS, maybe you can get to it using an APDU. It seems technically possible:
First you will need JSR 177 SATSA-APDU. Check Nokia devices that have support for it at http://www.developer.nokia.com/Community/Wiki/Java_ME_API_support_on_Nokia_devices
Then you will have to create an SMS APDU just like an STK Applet would do. Please check "Sending a message in the PDU mode" at http://www.dreamfabric.com/sms/
I did not try this, but this is the path I would go if I had to. If it does work with you, please share.

Resources