Micro Power Snitch

Periodically send a wireless data packet using energy harvested from a Current Transformer

Git repository: https://git.jeelabs.org/embello/tree/projects/mps

Status 2015-05

• Final build with custom PCB, works as intended
• In DC operation the polarity shown on the schematic for the CT connection is reversed
• Design files are in the mps area of the Embello Git repository
• Depending on PCB rev, Q2, Q3 and others may need special orientation:

Weblog posts

Introduction – Feb 2015

• Picking up magnetic energy
• Collecting energy into a reservoir
• First goal: just some blips

Micro Power Snitch, part 2 – Feb 2015

• Setting up a test power source
• The first MPS circuit
• Yes, the MPS lives, but…
• Adding a voltage monitor

Micro Power Snitch, part 3 – Mar 2015

• Pretty picture, ugly effect
• An improved MPS circuit
• It’s all about the startup “hump”
• Investigating the voltage doubler

Micro Power Snitch, part 4 – Mar 2015

• A revised, complete MPS
• Extremely slow ramps
• Next MPS challenge: the radio
• The MPS as prototype PCB

Micro Power Snitch, last part – Mar 2015

• Sending out MPS packets
• Construction and final notes

Micro Power Snitch, part 6 – Apr 2015

• The PCB that got everything wrong
• Back on track – now the hard part

Micro Power Snitch, part 7 – May 2015

• Let’s switch to a better MOSFET
• Anatomy of a power-up
• Power through I/O pins?
• Taming the radio startup current

Micro Power Snitch, success! – May 2015

• The MPS really works
• Should we send, or not?
• MPS component improvements
• Final MPS schematic and PCB