Computing stuff tied to the physical world

RFM69 on Raspberry Pi

In Book on May 20, 2015 at 00:01

With the Micro Power Snitch sending out packets, it’d be nice to be able to receive them!

This week is about turning a Raspberry Pi, or a similar board such as an Odroid-C1, into a Linux-based central node for what could become a home-based Wireless Sensor Network.

All it takes is an RFM69 radio module and a little soldering:

DSC 5086

On the menu for this week’s episode:

And before you know it, you’ll be smack in the middle of this century’s IoT craze…

(For comments, visit the forum area)

Micro Power Snitch, success!

In Book on May 13, 2015 at 00:01

We’ve come to the eighth and final episode of the Micro Power Snitch story: it’s working! The circuit is transmitting wireless packets through the RFM69 radio module running on nothing but harvested electromagnetic energy. Install once, run forever!

But there are still several little details, optimisations, and edge cases we need to take care of – which is what this week’s articles are all about. As always, one article per day:

The MPS triggers on any appliance drawing ≥ 500W (on 230 VAC, or 250W for 115 VAC):

DSC 5089

As always on the JeeLabs weblog: everything is open source – you are welcome to build and adapt this circuit for your own purposes. If you do, please consider sharing your suggestions/findings/improvements on the forum, for others to learn and benefit as well.

(For comments, visit the forum area)

Micro Power Snitch, part 7

In Book on May 6, 2015 at 00:01

The two problems with projects powered by harvested energy, are: 1) running out of juice, and 2) falling into a state of limbo and not (or not consistently) getting out of it again.

Here is an example of both happening – a successful µC startup and then a radio failure:

SCR97

In the case of the Micro Power Snitch, the energy coming in may vary greatly, since it will be proportional to the current drawn by the appliance being monitored by our MPS.

We’re going to have to tread carefully in this week’s episode:

As usual, each of the above articles will be ready on successive days.

Planned for next week: a few more loose ends, and then my closing notes.

(For comments, visit the forum area)