Node running on supercaps and a solar panel.
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For this type of comparison, I think you're better off charging up the supercap in a standardized way and then running with the solar panel disconnected. Otherwise, how recently and how long the supercap was charged to full capacity can affect the rate of discharge.
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Maybe it has to do with the harvesting chip. My graph looks like a sawtooth from day to day.
@gohan there is no harversting - this is just 30F cap connected to a node.
I have two setups:- BQ25570 + 2x10F supercaps in series and a small solar panel connected to a node. This is an excellent setup which can last for days without recharging
- 30F cap connected directly (initially I tried it via mcp1640) to a different node. The above graphs are from this setup.
I am re-measuring it them right now as the code was wrong.
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@gohan Well, the point is that signing does take more tx time. Therefore, voltage does drop upto 0.2-0.3V.
I am not sure about irregularities though
@alexsh1 with signing you also get message bursts. Not only is the max size data transmitted for every signed message, two more messages are exchanged; a nonce request (small) and a nonce (big).
Do you feel secure today? No? Start requiring some signatures and feel better tomorrow ;)
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@alexsh1 with signing you also get message bursts. Not only is the max size data transmitted for every signed message, two more messages are exchanged; a nonce request (small) and a nonce (big).
@anticimex said in Node running on supercaps and a solar panel.:
@alexsh1 with signing you also get message bursts.
That's clearly visible on the graph.
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I have got my hands on 30F 2.7V supercapacitor.
With it was charged for the first time, it only lasted sending 2583 times (1 time a minute voltage and an 20ms LED pulse and then sleeping; sleeping consumption is 4-5uA). The number is a bit disappointing. It is however connected via boost MCP1640 to provide the node with a stable 3.3V. I may try to get the supercapacitor connected directly to the node to see if I can extract more packets.
@alexsh1 said in Node running on supercaps and a solar panel.:
I have got my hands on 30F 2.7V supercapacitor.
With it was charged for the first time, it only lasted sending 2583 times (1 time a minute voltage and an 20ms LED pulse and then sleeping; sleeping consumption is 4-5uA). The number is a bit disappointing. It is however connected via boost MCP1640 to provide the node with a stable 3.3V. I may try to get the supercapacitor connected directly to the node to see if I can extract more packets.
Supercap connected directly to the node stopped working at 2V.
I got about 8949 packets (10ms LED and sent voltage every minute. No signing). It has been running about 6 days.
