On Fri, Jan 29, 2016 at 8:18 PM, David Carkeek <dcarkeek@gmail.com> wrote:

The IMEC WUR consumes 310uW. That’s too much to leave it on all the time. If it’s going to duty cycle then time synchronization will be needed anyway. What’s the win? It could stay on for longer periods but you still have some degree of time synchronization to contend with, unless I am missing something.

This is an interesting chip I found tonight.
The receiver draws less than 1.9mA at 1.2V-1.8V.  That is 2280 uW, 7x the IMEX WUR, but it’s a full radio, and still not a lot of power. The nRF52 receiver draws min 5.8mA in non-BLE mode. The minimum operating voltage is 1.7V. I don’t know if the current would be the same at 1.7V but assume it is. 1.7V * 0.0058 = 9860 uW, 32x the IMEC WUR power or about 4x the ZL70250.
The ZL70250 comes in a 3mm x 2mm package, so it’s small. It has an SPI interface so it could be controlled by the M4 in the nRF32. This radio could be added without taking up much space. Do you think it could do the network building/meshing? SInce it’s 700-900 MHz it would go through walls easier.
It would be interesting to know if the IMEC device is going to be just a WUR or if it will be a transceiver, and its frequency.


Yes, and it sniffs too.  Designed for body-area networks.  I wonder how big the antenna is.  36 pins?  Uses both SPI and IC simultaneously?

Does it use a BGA?  Is there an eval board?

The ZL70250 is not recommended for new designs. Please see our new Sub-GHz Radio Transceivers.
ZL70251 is more recent, but perhaps not the same thing?

Sniffing increases latency, but for our kind of app a second or two of latency per hop might be just fine.   Imagine that it takes 3-4 hops to get back to the WiFi router, then it might be 4 seconds before a connection is made – hardly a calamity.  If all the nodes are off except for this radio, and then they all wake up, do their meshing thing, and go to sleep, that might not be so bad either.  

A BLE beacon allegedly lasts for years (as long as it doesn’t beacon too often).

White paper: http://www.microsemi.com/document-portal/doc_download/127466-white-paper-ultra-low-power-short-range-radio-transceivers

Has a convenient list of the competitor’s products and their power consumptions. Need to look at the TZ1030 and EnOcean.

Inline image 1

Other radios


is only 3 meter transmission distance.

Inline image 1


33mA receive current.

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