Impc001 bluetooth device


#1

Do you recommend any suitable BLE 4/5 modules that can interface to ImpC001 device over UART ?
We have used Laird module BL654 attached in the past which use nRF52840BL654 Product Brief - PRELIMINARY.pdf (561.5 KB) SOC from Nordic and would like to use this part again.


#2

In the short term, we will be supporting the Murata 1DX and 1MW modules (which do WiFi as well as BLE, though WiFi won’t be supported for a little while yet by impOS on impC001). The BLE needs to be a Cypress/Broadcom BLE chip, as the patch ram loader is designed for those chipsets.

These are semi-generic BT HCI serial interface devices vs the “BLE+MCU” of the nRF52840 device - ie the stack intelligence is on the imp side, not within the BLE module.


#3

Ok I understand.

On the bluetooth side, an important use case is monitoring BLE beacons that transmit only and use the Imp as a gateway to cloud for these transmissions without any pairing.
In this case, we could simply use serial AT commands from Imp to setup the Laird module or place this module in Bridge mode where BT packets are passed through unaltered to the serial port of IMP.
If we use the Cypress BLE/Wifi module specified, can we still use the above beacons use case with IMPC001 ?


#4

Yes, it’s intended to implement the whole “built-in” Bluetooth API on impC001 for those Cypress modules, so that it works the same way as is documented here for the imp004. See, for example, the bluetooth.startscan() call.

Peter


#5

Also, there are modules that will be available shortly which allow you to plug the 1MW module into an impC001 breakout (it goes into the click socket with the additional 4 pin header). We have these now, but won’t be shipping them until the software support is in for BLE.


#6

The 1MW Murata module have an MOQ order of 2K pieces only.

If we use Murata 1DX module instead which is available in low volumes, will BT on ImpC001 be compatible and will any sample code for your 1MW click board able to run also on 1DX module ?


#7

For BLE, 1DX and 1MW will behave the same way; we picked 1MW for the breakout plug-in as this allowed the most flexibility for WiFi (ie you get dual band).

The only change to the sample code is the BLE firmware blob passed into bluetooth.open is different for the 1DX/1MW. After that point everything will behave the same way.


#8

The 1MW module is a BT5 capable device as well which may be another advantage over 1DX module.
Another question is how do you connect to external WiFi AP gateway using the impC001 with 1DX module to get imp data to your server when cellular goes down ?
And especially, if the device is mobile with wifi hotspots.


#9

We don’t currently have plans to support BT5, but yes the 1MW has a newer radio.

Multiple concurrent network support is coming to impOS in release 42 (which enables things like 005 to use ethernet for local networking whilst communicating to the cloud over wifi), and to the impC001 in release 44.


#10

Hugo, we go with 1DX module for design.
Many thanks for your prompt and knowledgeable replies.

Sean.