Low power wireless receiver - Page 1
Forum section: electronics / projects

author: teedee
author_rank: Newbie
timestamp: December 30, 2014, 10:09:52 pm
content: Hi,I'm trying to find a wireless chip that can perform as a receiver to meet the following specs:- current consumption < 5mA- communication range > 30 meters and can penetrate through typical obstacles like house walls or floors- has sleep mode and over-the-air wake-up ability (assuming the current consumption can only be be met with this feature)I have been looking at different BLE, Zigbee, and low power wifi components from TI and NXP but haven't found a good one yet.Any help here would be greatly appreciated. I'm open to any kind of wireless technology and brands as long as it can achieve the specs.Thanks.

author: Howardlong
author_rank: Super Contributor
timestamp: December 31, 2014, 11:22:40 am
content: Narrowband devices like Microchip's MiWi in the 433 or 868/915MHz license free bands may work for you: the nature of the propagation at these frequencies combined with narrowband signals will improve range somewhat over typical 2.4GHz solutions.

author: Codemonkey
author_rank: Regular Contributor
timestamp: December 31, 2014, 12:09:49 pm
content: It would be helpful if you could describe your application a bit.Over air wakeup ability implies that in order to receive the wake up command, the receiver must be on to do so. Generally, the best way to achieve very low power sleep modes in a wireless device that expects to receive information, is for that low power device to periodically wake up and poll a permanently on (main powered) device to see if there are any messages waiting for it.

author: Circuitous
author_rank: Unknown
timestamp: December 31, 2014, 01:49:43 pm
content: I've been looking at the nRF25L01+ recently. It meets most of your specs... Might be too high on power consumption by a few ma.

author: teedee
author_rank: Newbie
timestamp: December 31, 2014, 05:28:23 pm
content: Thanks all for your comments.The nRF25L01+ looks like a nice transceiver but at 8.9mA for Rx, it's still a bit high for me. My application is simply a hub that listens to other sensors for notifications. SO technically, the hub doesn't need to be active all the time. Ideally I want the hub to sleep after it establishes connections with all sensors, then wake up whenever receiving a notifications (i.e. wake-up call over the air). This hub will run on a 1500mAh battery and needs to last at least for a week or more. It doesn't need a high bandwidth. Something around 1Mbps should be sufficient. However, it does need to cover a 30m range which may have obstacles like walls and floors. I just looked at the Microchip MRF89XAM9A-I/RM and it seems a good one with 3mA for Rx. However, this is on the datasheet. I guess I won't know the performance until I try it out.

author: Howardlong
author_rank: Super Contributor
timestamp: January 01, 2015, 02:13:02 pm
content: 1Mbps is not going to work with narrowband solutions.What you're trying to achieve won't work at all if you need that kind of bandwidth and less than 5mA rx current.You might want to explain what you're trying to achieve, we might be able to help provide you with a solution.

author: Howardlong
author_rank: Super Contributor
timestamp: January 01, 2015, 02:33:27 pm
content: By the way, this document you might find usefulhttp://ww1.microchip.com/downloads/en/AppNotes/00001631A.pdfI would say that in my experience those results are optimistic, but it gives you an idea of practically what to expect.