Ultra low power energy harvester from BPW34

After hours/days of debugging and tuning I have working reliable transmission.

Some facts:

Transmission time for 16bit data with 1200bps is 34ms with all sync and receiver tuning bites

Harvester features:

Key timing component is middle capacitor, and there is some power facts
As load is connected Attiny85/1Mz with running code (no sleep) without transmitter

Power supply length

• 100n = 15ms run-time every 1s
• 1uF = 17ms run time every 13s
• 10uF = 35ms every 60s

I have now reliable transmission for 16bit value every 30minutes, It is little long time but I am on beginning
with this project.

Without load is power supply pulse 60ms long every 60s 

Yes, finally boards are home. All working good :)

I finished harvester demonstrator with wireless transmitter and Attiny85

Solar array is large but I have plan to use only 4 diodes.

I try charge pump with attiny85 1Mhz

digitalWrite(LED,HIGH);
delayMicroseconds(1);
digitalWrite(LED,LOW);
delayMicroseconds(150); // runtime delay
digitalWrite(LED2,HIGH);
delayMicroseconds(10);
digitalWrite(LED2,LOW);

With dirty trial and error experiments I adjusted, maximum run time is 150uS with 1Hz repeating 

Of course there is lot of possibilities to charge additional capacitor but unfortunately voltage rising very very slow and micro-controller can not start.

I think 150us is enough to send very short maybe 8bit packet with simple 433Mhz ASK/OOK radio

Success for 4 small diode power supply

It is time do design first more complex board :)

After breadboard success I designed first application .... flashing heart, first batch was just only garbage due mistake in design.

As you can see on first video, led flashing in room light.

Power output is short 2V pulse.

I created all on breadboard and about month experimentally adjust components values to get best performance.

Charge pump schematic.