Moteino model vs range vs power ?

[jassing]

there are a few options for the moteino --- I am not picky on model or which radio module to use... I would like 433mhz & 150meter range and low power...

I need to run something (in a remote area, battery (solar) powered) that sends out a signal (really just a "yes" or "no" type signal, a byte of data is fine) every 30 seconds or so... 

I would give more weight to Power usage over range -- it is "line of sight" w/o much to interfere...

Any suggestion on which boards & radio modules to use?

Thanks

[TomWS]

there are a few options for the moteino --- I am not picky on model or which radio module to use... I would like 433mhz & 150meter range and low power...

I need to run something (in a remote area, battery (solar) powered) that sends out a signal (really just a "yes" or "no" type signal, a byte of data is fine) every 30 seconds or so... 

The question is: What does the mote need to do when it's not sending once every 30 seconds, if it can be sleeping, then no problem with any of them.  If it needs to be doing something else that's consuming battery power then you need to be more careful on selection/design.

I would give more weight to Power usage over range -- it is "line of sight" w/o much to interfere...

No other objects like trees, buildings, or railroad cars in the way?  Seriously?

Any suggestion on which boards & radio modules to use?

Thanks

Need one more piece of information: What is your battery volume constraint?  Gotta be a coin cell battery or a 450CCA car battery is fine...

Tom

[jassing]

Thanks Tom.
When it's not sending, it needn't do anything... but: if a signal (interrupt) is received, it needs to know that -- did it go high to low, or low to high...  Otherwise, it can sleep the day away waking 30 seconds to send the a byte; then sleep for another 30 seconds (or interrupted).

Battery will be a LiPo battery of some sort 18650 or a 2000mah; single cell battery... Can't use a car (or lawn tractor) battery, need to keep the total footprint down ...

Line of sight: Well, If I stand in the middle of the road, I can see the target.  However, we'll be driving on the road (so not 'dead center') and while in the drivers seat, I can't see it unless I cross the center line...

[jarrods]

It sounds like any of the Moteino and Radio combinations would work. however you need to be mindful of the frequency. 433mhz is not an ISM band in the US (you need a license to use it). So if you want to use that frequency then you will need check your local Regulations.

A recent test I did: a Moteino with the 915MHz HW radio. I used a 850mAH Lipo and started fully charged. Moteino was set to call home every 1 second. after 48 hours I still had ~45% of the battery left. Using just the wire antenna I was about to get ~300 feet in a urban environment (trees, homes, etc).

So if you are beaconing every 30 seconds then you could likely get away with a <500mAH battery and a 2w Solar panel and charger and it should cover you for a few days even if there is not enough sunlight to charge.


what you could do is start with the wire antenna and see how that works. Then later solder on an SMA connector and add a "nice antenna" if you don get the range you looking for.

Also when your programming this ask yourself "if there is nothing to report do I need to send back a message?" if you are using interrupts or have something that is monitoring a Sensor, then you can keep the "ping" saying everything is ok and here is my battery level at like 5 or 10 minutes. Then only when there is an Event do you send a event message right away.

Using an approach like that you can drop your power usage to almost nothing cause your device will be sleeping most of the time.

[Felix]

Jarrods is correct.
I would add that you can dramatically improve range/sensitivity if you narrow the RX bandwidth (RX_BW) and lower the bitrate. Several threads in the forums talk about this and the results.

[jassing]

Thanks for the info -- I thought 433 was available, 315? I could have sworn there was a freq around there that was available to use... There's a sensor that someone uses around here that alerts via gmrs, so perhaps using on of those frequencies?
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The idea is to do a drive by and get a green or red light on the dash - but drive by is just that, not to, or within a foot.   at 25mph we're "close" to it for about 40 seconds until getting out of line of sight -- which is why the 'every 30 second' to ensure we get the info.
I can lower the baud rate as much as needed -- I was just thinking to send a single byte, where there would be 2 bits set, followed by 1 bit which woudl be 0 or 1 2 more bits set..... (5 bits total, our on/off signal surrounded by two set bits)
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Thanks for the ideas -- I have more info to go on now...

[jarrods]

Well for that 915 would likely work fine. If you have reception issues (which i doubt at that distance) then you can put a suction cup antenna on the roof of your car.