Sorry fanoush correction. I used a modified version of bleak.
Original version worked!! at last thanks to you and Gordon.
I have plenty more to do with this but I hope I wont have to bother you too soon.
For completeness
Watch No change from above.

Console

Connecting...
Connected
Writing command
Waiting for data
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'=undefined\r\n>')
RX> bytearray(b'=undefined\r\n>')
Done!

Hi fanoush,
Thanks.
I presumed you meant I should add your suggestion to my code app.
I did that and still no result yet.
Code on watch

E.showMessage("Hello Code");

function Y(dict) {
  E.showMessage(dict.Code);
  
}

Console

Connecting...
Connected
Writing command
RX> bytearray(b"Y(\'+json.dumps(dict)")
RX> bytearray(b"Y(\'+json.dumps(dict)")
RX> bytearray(b"+\')\r\n")
RX> bytearray(b"+\')\r\n")
Waiting for data
RX> bytearray(b'Uncaught Error: Cann')
RX> bytearray(b'Uncaught Error: Cann')
RX> bytearray(b"ot read property \'sp")
RX> bytearray(b"ot read property \'sp")
RX> bytearray(b"lit\' of undefined\r\n ")
RX> bytearray(b"lit\' of undefined\r\n ")
RX> bytearray(b'at line 1 col 249\r\n.')
RX> bytearray(b'at line 1 col 249\r\n.')
RX> bytearray(b'..Rect(c/2-b,44,c/2+')
RX> bytearray(b'..Rect(c/2-b,44,c/2+')
RX> bytearray(b'b,45)}b=e.split("\\n"')
RX> bytearray(b'b,45)}b=e.split("\\n"')
RX> bytearray(b');var h=(f-16*b.leng')
RX> bytearray(b');var h=(f-16*b.leng')
RX> bytearray(b'th...\r\n             ')
RX> bytearray(b'th...\r\n             ')
RX> bytearray(b'                 ^\r\n')
RX> bytearray(b'                 ^\r\n')
RX> bytearray(b'in function called f')
RX> bytearray(b'in function called f')
RX> bytearray(b'rom line 1 col 24\r\nE')
RX> bytearray(b'rom line 1 col 24\r\nE')
RX> bytearray(b'.showMessage(dict.Co')
RX> bytearray(b'.showMessage(dict.Co')
RX> bytearray(b'de);\r\n              ')
RX> bytearray(b'de);\r\n              ')
RX> bytearray(b'         ^\r\nat line ')
RX> bytearray(b'         ^\r\nat line ')
RX> bytearray(b'1 col 24\r\nE.showMess')
RX> bytearray(b'1 col 24\r\nE.showMess')
RX> bytearray(b'age(dict.Code);\r\n   ')
RX> bytearray(b'age(dict.Code);\r\n   ')
RX> bytearray(b'                    ')
RX> bytearray(b'                    ')
RX> bytearray(b'^\r\nin function "Y" c')
RX> bytearray(b'^\r\nin function "Y" c')
RX> bytearray(b'alled from line 1 co')
RX> bytearray(b'alled from line 1 co')
RX> bytearray(b"l 23\r\nY(\'+json.dumps")
RX> bytearray(b"l 23\r\nY(\'+json.dumps")
RX> bytearray(b"(dict)+\')\r\n         ")
RX> bytearray(b"(dict)+\')\r\n         ")
RX> bytearray(b'             ^\r\n>')
RX> bytearray(b'             ^\r\n>')
Done!

Looks like my code didnt post well, I will try again.

bleak code

#!/usr/bin/env python3

import asyncio
import array
from bleak import discover
from bleak import BleakClient
import json

[#create](https://forum.espruino.com/search/?q=%23create) dictionary for the data to be sent
dict = {'Code': '10'}

address = "D8:AB:E0:B7:F5:AE"
UUID_NORDIC_TX = "6e400002-b5a3-f393-e0a9-e50e24dcca9e"
UUID_NORDIC_RX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"

command = "Y('+json.dumps(dict)+')\n"


def uart_data_received(sender, data):
    print("RX> {0}".format(data))

async def run():
    devices = await discover()
    for d in devices:
        print(d)

print("Connecting...")
async def run(address, loop):
    async with BleakClient(address, loop=loop) as client:
        print("Connected")
        await client.start_notify(UUID_NORDIC_RX, uart_data_received)
        print("Writing command")
        c=command
        while len(c)>0:
          await client.write_gatt_char(UUID_NORDIC_TX,bytearray((c[0:20]),'utf-8') , True)
          c = c[20:]
        print("Waiting for data")
        await asyncio.sleep(1.0, loop=loop) # wait for a response
        print("Done!")


loop = asyncio.get_event_loop()
loop.run_until_complete(run(address, loop))

Console

Connecting...
Connected
Writing command
Waiting for data
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'Uncaught Error: Func')
RX> bytearray(b'Uncaught Error: Func')
RX> bytearray(b'tion "split" not fou')
RX> bytearray(b'tion "split" not fou')
RX> bytearray(b'nd!\r\n at line 1 col ')
RX> bytearray(b'nd!\r\n at line 1 col ')
RX> bytearray(b'250\r\n...ect(c/2-b,44')
RX> bytearray(b'250\r\n...ect(c/2-b,44')
RX> bytearray(b',c/2+b,45)}b=e.split')
RX> bytearray(b',c/2+b,45)}b=e.split')
RX> bytearray(b'("\\n");var h=(f-16*b')
RX> bytearray(b'("\\n");var h=(f-16*b')
RX> bytearray(b'.length)...\r\n       ')
RX> bytearray(b'.length)...\r\n       ')
RX> bytearray(b'                    ')
RX> bytearray(b'                    ')
RX> bytearray(b'   ^\r\nin function ca')
RX> bytearray(b'   ^\r\nin function ca')
RX> bytearray(b'lled from line 1 col')
RX> bytearray(b'lled from line 1 col')
RX> bytearray(b' 19\r\nE.showMessage(d')
RX> bytearray(b' 19\r\nE.showMessage(d')
RX> bytearray(b'ict);\r\n             ')
RX> bytearray(b'ict);\r\n             ')
RX> bytearray(b'     ^\r\nat line 1 co')
RX> bytearray(b'     ^\r\nat line 1 co')
RX> bytearray(b'l 19\r\nE.showMessage(')
RX> bytearray(b'l 19\r\nE.showMessage(')
RX> bytearray(b'dict);\r\n            ')
RX> bytearray(b'dict);\r\n            ')
RX> bytearray(b'      ^\r\nin function')
RX> bytearray(b'      ^\r\nin function')
RX> bytearray(b' "Y" called from lin')
RX> bytearray(b' "Y" called from lin')
RX> bytearray(b'e 1 col 17\r\nY({"Code')
RX> bytearray(b'e 1 col 17\r\nY({"Code')
RX> bytearray(b'": "10"})\r\n         ')
RX> bytearray(b'": "10"})\r\n         ')
RX> bytearray(b'       ^\r\n>')
RX> bytearray(b'       ^\r\n>')

Code on watch

E.showMessage("Hello Code");

function Y(dict) {
  E.showMessage(dict);
  
}

Thanks Gordon,
So I now have double quotes back in and I have tested the connection and it has worked ok so far in terms of not giving the connection error.However the console output looks werid and the watch display is blank.
So I will post the complete code.

``
#!/usr/bin/env python3

import asyncio
import array
from bleak import discover
from bleak import BleakClient
import json

#create dictionary for the data to be sent
dict = {'Code': '10'}

address = "D8:AB:E0:B7:F5:AE"
UUID_NORDIC_TX = "6e400002-b5a3-f393-e0a9-e50e24dcca9e"
UUID_NORDIC_RX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
#command = "X("+json.dumps(dict)+")\n"
#command = b"E.showMessage('Hello','A Title')/n"
command = "Y("+json.dumps(dict)+")\n"

def uart_data_received(sender, data):

print("RX> {0}".format(data))

You can scan for devices with:

async def run():

devices = await discover()
for d in devices:
    print(d)

print("Connecting...")
async def run(address, loop):

async with BleakClient(address, loop=loop) as client:
    print("Connected")
    await client.start_notify(UUID_NORDIC_RX, uart_data_received)
    print("Writing command")
    c=command
    while len(c)>0:
      await client.write_gatt_char(UUID_NORDIC_TX,bytearray((c[0:20]),'utf-8') , True)
      c = c[20:]
    print("Waiting for data")
    await asyncio.sleep(1.0, loop=loop) # wait for a response
    print("Done!")

loop = asyncio.get_event_loop()
loop.run_until_complete(run(address, loop))

My app. Note function is now Y.

E.showMessage("Hello Code");

function Y(dict) {
E.showMessage(dict);

}

and the console

Connecting...
Connected
Writing command
Waiting for data
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'Uncaught Error: Func')
RX> bytearray(b'Uncaught Error: Func')
RX> bytearray(b'tion "split" not fou')
RX> bytearray(b'tion "split" not fou')
RX> bytearray(b'nd!\r\n at line 1 col ')
RX> bytearray(b'nd!\r\n at line 1 col ')
RX> bytearray(b'250\r\n...ect(c/2-b,44')
RX> bytearray(b'250\r\n...ect(c/2-b,44')
RX> bytearray(b',c/2+b,45)}b=e.split')
RX> bytearray(b',c/2+b,45)}b=e.split')
RX> bytearray(b'("\n");var h=(f-16*b')
RX> bytearray(b'("\n");var h=(f-16*b')
RX> bytearray(b'.length)...\r\n ')
RX> bytearray(b'.length)...\r\n ')
RX> bytearray(b' ')
RX> bytearray(b' ')
RX> bytearray(b' ^\r\nin function ca')
RX> bytearray(b' ^\r\nin function ca')
RX> bytearray(b'lled from line 1 col')
RX> bytearray(b'lled from line 1 col')
RX> bytearray(b' 19\r\nE.showMessage(d')
RX> bytearray(b' 19\r\nE.showMessage(d')
RX> bytearray(b'ict);\r\n ')
RX> bytearray(b'ict);\r\n ')
RX> bytearray(b' ^\r\nat line 1 co')
RX> bytearray(b' ^\r\nat line 1 co')
RX> bytearray(b'l 19\r\nE.showMessage(')
RX> bytearray(b'l 19\r\nE.showMessage(')
RX> bytearray(b'dict);\r\n ')
RX> bytearray(b'dict);\r\n ')
RX> bytearray(b' ^\r\nin function')
RX> bytearray(b' ^\r\nin function')
RX> bytearray(b' "Y" called from lin')
RX> bytearray(b' "Y" called from lin')
RX> bytearray(b'e 1 col 17\r\nY({"Code')
RX> bytearray(b'e 1 col 17\r\nY({"Code')
RX> bytearray(b'": "10"})\r\n ')
RX> bytearray(b'": "10"})\r\n ')
RX> bytearray(b' ^\r\n>')
RX> bytearray(b' ^\r\n>')
Done!

```
Any help most appreciated.

Thanks Gordon,
I have tried your suggestion but bleak throws an error, which I will show below.
My single quotes show jason.dump etc as before. This is also below.
However I am confused, as per conversation with fanoush, I thought my problem is for my function to convert the bytearray back to a string using javascript. ( Icant find a way to do this yet) but any clarity on this matter would help.
With the following

command = "Y("+json.dumps(dict)+")\n"

gives an error. Note I am not convinced that this is due to the command line as bleak seems a bit unstable.

File "/home/pi/.local/lib/python3.7/site-packages/bleak/backends/bluezdbus/client.py", line 146, in connect
    raise BleakError(str(e))
bleak.exc.BleakError: org.bluez.Error.Failed: Software caused connection abort

With this

command = "Y('+json.dumps(dict)+')\n"

``Console gives

Connecting...
Connected
Writing command
RX> bytearray(b"Y(\'+json.dumps(dict)")
RX> bytearray(b"Y(\'+json.dumps(dict)")
RX> bytearray(b"+\')")
RX> bytearray(b"+\')")
RX> bytearray(b'\r\n')
RX> bytearray(b'\r\n')
Waiting for data
RX> bytearray(b'=undefined\r\n>')
RX> bytearray(b'=undefined\r\n>')
Done!

The watch displays

+json.dumps(dict)+
```

Sorry console didnt post right

Connecting...
Connected
Writing command
Waiting for data
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'Y({"Code": "10"})\r\n')
RX> bytearray(b'Uncaught ReferenceEr')
RX> bytearray(b'Uncaught ReferenceEr')
RX> bytearray(b'ror: "nY" is not def')
RX> bytearray(b'ror: "nY" is not def')
RX> bytearray(b'ined\r\n at line 1 col')
RX> bytearray(b'ined\r\n at line 1 col')
RX> bytearray(b" 25\r\nY(\'+json.dumps(")
RX> bytearray(b" 25\r\nY(\'+json.dumps(")
RX> bytearray(b'dict)+\')/nY({"Code":')
RX> bytearray(b'dict)+\')/nY({"Code":')
RX> bytearray(b' "10"})/nY({"Code": ')
RX> bytearray(b' "10"})/nY({"Code": ')
RX> bytearray(b'"10"}...\r\n          ')
RX> bytearray(b'"10"}...\r\n          ')
RX> bytearray(b'              ^\r\n>')
RX> bytearray(b'              ^\r\n>')
Done!

Thanks got you.
I now get output on the watch. Not what I want but progress.
Watch shows

+json.dumps(dict)+

Console shows

Connecting... Connected Writing command Waiting for data RX> bytearray(b'Y({"Code": "10"})\r\n') RX> bytearray(b'Y({"Code": "10"})\r\n') RX> bytearray(b'Uncaught ReferenceEr') RX> bytearray(b'Uncaught ReferenceEr') RX> bytearray(b'ror: "nY" is not def') RX> bytearray(b'ror: "nY" is not def') RX> bytearray(b'ined\r\n at line 1 col') RX> bytearray(b'ined\r\n at line 1 col') RX> bytearray(b" 25\r\nY(\'+json.dumps(") RX> bytearray(b" 25\r\nY(\'+json.dumps(") RX> bytearray(b'dict)+\')/nY({"Code":') RX> bytearray(b'dict)+\')/nY({"Code":') RX> bytearray(b' "10"})/nY({"Code": ') RX> bytearray(b' "10"})/nY({"Code": ') RX> bytearray(b'"10"}...\r\n ') RX> bytearray(b'"10"}...\r\n ') RX> bytearray(b' ^\r\n>') RX> bytearray(b' ^\r\n>') Done! `
I will try the acii next.
Thanks

I am sorry I dont understand what you mean?

Hi fanoush, thanks for your patience.
So to go back I made the following changes but I stiil get no display on the watch. Just to note the function has changed to Y rather than X.
This is the console output.

Connecting...
Connected
Writing command
Waiting for data
RX> bytearray(b'Y({"Code": "10"})/n')
RX> bytearray(b'Y({"Code": "10"})/n')
Done!

Putting the command back to what is was

command = "Y("+json.dumps(dict)+")/n"

and my app function is now

E.showMessage("Hello Code");

function Y(dict) {
  E.showMessage(dict);

}

Thanks fanoush.
Re my understanding yes you are probably right.
To clarify I thought this line converted the python dictionary to a string:-

command = "X('+json.dumps(dict)+')/n"

and this line converted the json string to bytes:-

await client.write_gatt_char(UUID_NORDIC_TX,bytearray((c[0:20]),'utf-8') , True)
          c = c[20:]

I thought this would then be sent and my function would decode the bytes back to a json string:-

E.showMessage("Hello Code");

function X(dict) {
  msg = json.loads(dict.decode('utf-8'));
  
  E.showMessage(msg);

}

I dont now get the previous error, but the bleak library seems a little unreliable and gives a connection failure after a few attempts. However I am getting no response on the watch so I cant say its working yet.
I will try ascii and see if there's a difference,but I really need a more reliable bluetooth tranfer code. Hopefully the code comes out OK.
Many thanks for your help.
mike

thanks for that
I have amended the code.

command = "X('+json.dumps(dict).encode('utf-8')+')/n"

and

await client.write_gatt_char(UUID_NORDIC_TX,bytearray((c[0:20]),'utf-8') , True)
          c = c[20:]

Not sure if I need both utf-8's, however I am assuming that passing this to my function I will need to decode it.

Fanoush,
Thank you tried but still get an error

File "/home/pi/bleak-test.py", line 34, in run
    await client.write_gatt_char(UUID_NORDIC_TX, bytearray(c[0:20]), True)
TypeError: string argument without an encoding

Thanks I will try that.

Hi Gordon,
Many thanks for the response.
I decided to make an app for this to make things a bit more visible.
However I get an error with json.dumps, which is

Traceback (most recent call last):
  File "/home/pi/bleak-test.py", line 15, in <module>
    command = b"X("+json.dumps(dict)+")\n"
TypeError: can't concat str to bytes

I added this snippet to bleak to creates the variable.

import json

[#create](https://forum.espruino.com/search/?q=%23create) dictionary for the data to be sent
dict = {'Code': '10'}

And for completeness my app does this

E.showMessage("Hello Code");

function X(dict) {
  E.showMessage(dict);

}

So do I have to convert the json to bytes?
Thanks for your patience
mike

Hi Guys,
Thanks for your replies.
Fanoush, your approach is a little beyond my experience at this point but thank you.
Gordan , are (some, data) variables passed to the functon?
Does myapp.boot.js run in the background or do i need to to write an info file as described in your tutorials.
Sorry for the basic level of my response.

Having got the data to the bangle can any one advise how this could be captured by an app on the bangle to manage the code style etc
Many thanks

Hi ,Thanks for that.
It displayed on the watch so, so far so good.
This is the shell output
Connecting...
Connected
Writing command
RX> bytearray(b"E.showMessage(\'Hello")
RX> bytearray(b"\',\'A")
RX> bytearray(b" Title\')\r\n")
Waiting for data
RX> bytearray(b'Uncaught ReferenceEr')
RX> bytearray(b'ror: "nE" is not def')
RX> bytearray(b'ined\r\n at line 1 col')
RX> bytearray(b" 36\r\n...ssage(\'Hello")
RX> bytearray(b"\',\'A Title\')/nE.show")
RX> bytearray(b"Message(\'Hello\',\'A T")
RX> bytearray(b"itle\')...\r\n ")
RX> bytearray(b' ')
RX> bytearray(b' ^\r\n>')
Done!
It doesnt look to clean. Is that down to how much data it can send?
Also do you now anything re UUIDNORDIC TX and RX?
Many Thanks

As a follow on from a previous post( Espruino Hub and BLE) I am trying to connect a raspberrypi to the bangle and send from the pi a short message or two digit code.
I have researched the espruino ref https://www.espruino.com/Interfacing#bluetooth-le, and in so doing came across a ble wrapper called bleak.
This seems suited to my purpose but whilst it will connect and appear to send data it the data does not show on the bangle.
I also do not know what ref I would need for these to entries (UUID_NORDIC_TX = ""
UUID_NORDIC_RX = ""
If it helps this is the shell output

Connecting...
Connected
Writing command
RX> bytearray(b"E.showMessage(\'Hello")
RX> bytearray(b"\',\'A")
RX> bytearray(b" Title\')/n")
Waiting for data
Done!

and this is the python code

e#!/usr/bin/env python3

import asyncio
import array
from bleak import discover
from bleak import BleakClient

address = "D8:AB:E0:B7:F5:AE"
UUID_NORDIC_TX = "6e400002-b5a3-f393-e0a9-e50e24dcca9e"
UUID_NORDIC_RX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
command = b"E.showMessage('Hello','A Title')/n"

def uart_data_received(sender, data):
    print("RX> {0}".format(data))

# You can scan for devices with:
[#async](https://forum.espruino.com/search/?q=%23async) def run():
#    devices = await discover()
#    for d in devices:
#        print(d)

print("Connecting...")
async def run(address, loop):
    async with BleakClient(address, loop=loop) as client:
        print("Connected")
        await client.start_notify(UUID_NORDIC_RX, uart_data_received)
        print("Writing command")
        c=command
        while len(c)>0:
          await client.write_gatt_char(UUID_NORDIC_TX, bytearray(c[0:20]), True)
          c = c[20:]
        print("Waiting for data")
        await asyncio.sleep(1.0, loop=loop) # wait for a response
        print("Done!")

Any guidance appreciated.

Gordan, Thank you for your reply which I shall pursue.
Could you briefly explain what the EspruinoHub is?
Wha do I expect when its installed?
Many thanks.

I would like to transfer data from a raspberrypi TO my Banglejs.
The data would be a series of probable two digit codes which would describe various status indicators from an app running on the Pi.
The reason for using the watch is an easy way to receive alerts etc as it will be used outdoors in the countryside connecting to the pi over a local connection.
I am wondering ( having read the git posting) if mqtt is a method of achieving this and if there are any examples of this being done.
many thanks for any suggestions.

Thanks for that.
I will use btn 1 and write some code in the emulator first.

Hi,
New to the watch and wonder if there is a tutorial on programming the buttons.
I have followed the tutorial on Banglejs data storage poi logger and would like to use the buttons to register a poi on the move rather than use the screen and scroll down.
Any guidance appreciated.