In the midst of the Corona Pandemic we are looking to develop a wearable sensor that when within approximately 2m of another (of the same type) of wearable sensor will log an event.
The ideal would be a low cost and very low power. It must work without line of sight since the sensor can be in your pocket etc. I've looked at all sorts of proximity sensors and none seem to be able to do the job.
My only solution I could come up with is a sub Ghz RF transceiver that polls (twice every second) and is in receive mode for the rest of the time and when a message is received an ACK is sent. The output power will be set very low (0 dbm) without an antenna so should get around 1.5 to 2.5 m range irrespective of a human body that is in between sender and receiver (If I go with my intuition).
Problem is that lowest RX current is around 7mA which means on a 1000mA battery will last less than a week.
Has any body done anything similar or have any advise on maybe another type of technology I can use?
Location is not important and it is most likely going to be indoor.
Any advise will be highly appreciated
Hello,
I had the same idea a few days ago, to create a device with the aim of guaranteeing the safety distance between people and / or workers.
Your idea seems good to me. However, I am a novice, and I work with a team that has computer skills, and too little electronics.
I created a topic on the forum. Someone gave interesting ideas, but I am unable to develop. I'll send you the link to the discussion. Mutual distance between 2 sensors - Emergency Response: Covid-19 Projects - Arduino Forum
If you find something useful let me know.
I don't think, you will find such sensor and RF will consume battery. I think you should have a look at Bluetooth 4.0, they can do the job and are quite cheap.
Hi
I actually stumbled across this.
I company in New Zealand developed a device very similar to what we intend to develop.
They use BLE and the device is the size of a credit card. It states that battery can last 12 months. How could this be possible? can you continuously scan with BLE and get 12 months on a battery the size of a credit card, or am I missing something here?
Here is the news article: Coronavirus: New Zealand considering $100m contact tracing ‘CovidCard' | Stuff.co.nz
How could this be possible?
Because NZ has a low population density?