Connect RPI with Bangle and send data

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](http://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.