BLE multiple characteristics in a service

[TravisT]

I seem to be having trouble getting more than one characteristic working inside of a BLE service. The below simple example is based on what is shown in the class documentation. There is not much more to help understand programming a BLE peripheral with Micropython on the wipy2/lopy boards.

As mentioned in an email to support and in another post. I will be willing to pay for prompt support and resolution of this.

Any help would be appreciated.

https://docs.pycom.io/pycom_esp32/library/network.Bluetooth.html
https://docs.pycom.io/pycom_esp32/pycom_esp32/tutorial/includes/bluetooth.html

>>> from network import Bluetooth
>>> ble = Bluetooth()
BTDM CONTROLLER VERSION: 010101
btip start
copy .data from 4000d890 to 3ffae6e0, len 00001830
set .bss 0x0 from 3ffb8000 to 3ffbff70, len 00007f70
BTDM ROM VERSION 0101
BD_ADDR: 24:0A:C4:00:6B:EC
NVDS MAGIC FAILED
RF Init OK with coex
>>> ble.advertise(True)
>>> ble.set_advertisement(name='bleep', service_uuid=b'1234567890123456', manufacturer_data=None, service_data=None)
>>> serv = ble.service(uuid=b'1234567890123456', isprimary=True)
>>> char1 = serv.characteristic(uuid=b'2234567890123456', value=1)
>>> char2 = serv.characteristic(uuid=b'3234567890123456', value=2)

[jmarcelino]

@TravisT said in BLE multiple characteristics in a service:

serv = ble.service(uuid=b'1234567890123456', isprimary=True)

You need to use the nbr_chars parameter when you create a service.
For your example, with two characteristics, that would be:

serv = ble.service(uuid=b'1234567890123456', isprimary=True,nbr_chars=2)

This was added in 1.5.0.b1

[TravisT]

Thanks for the prompt help. This makes sense, just wish the documentation was better at describing typical use cases, especially when there is frequent firmware updates.

[panos29]

@jmarcelino Is there a maximum to how many characteristics a service can have?

[TravisT]

I know this is an old topic I started but it seems like there is even less documentation now on this topic of using the BLE device as a peripheral. It would be nice if the documentation better represented common functionality and how the functionality is intended to be used with this device.

I tried to use those links that had reference to using the BLE device as a peripheral but the link was broken.