The resistance did go down a bit (600 to 580) but that is no problem.
Yes, that's due to the extra voltage drop at the GPIO pin. This should be relatively consistent so you can probably reliably 'fudge' it. The alternative would be to drive with an external transistor, but it sounds like you're ok with this implementation.
Enjoy the fully filled pool!
Tom
Hi Tom -
Well, I am totally stumped and completely stumped. I left for the weekend and came back to find my moteino totally unresponsive. I could not figure out what was wrong. I connected it back to the computer and had problems reading or writing anything to it.
On a whim, I unplugged it form the 4 x AA Energizer Advanced Lithium batteries that I had it connected to over the weekend and the moteino came back to life. Weird I thought, so I grabbed a meter and checked the voltage on the batteries. 1.94 volts. They were dead. Grabbing four new batteries, they measured 6.67 volts. I plugged those in and the moteino came back to life.
These were all brand new batteries that I got on Friday.
So obviously my low power mote is anything but a low power mote having drained 4 x AA Lithium batteries in the space of three days.
I disconnected the lithium battery pack and threw my meter in the mix. With a new (non-lithium) battery pack reading 5.6v, I was drawing .007a (7mA) at "idle" and .013a (13mA) at read & transmit.
I took those reading and figured it based on Duracell's 2100mAh spec and figured I should have gotten somewhere close to 12 days (still horrible, but much better than 4 days).
I then put 4 new Lithium batteries on the mote (reading 6.8V) and the reading stayed the same (7mA and 13mA).
So then out of curiosity I went to two Lithium AA batteries (3.4v) and saw that my current draw dropped to 5mA (at "idle") from the 7mA above. Still it seems a bit high.
Then I threw on two Duracell AA batteries (2.95v) and something very strange happened. When I first connect the power, I see a jump in power from 0.000 to 0.006, but then it immediately drops to 0.000 again. I thought I lost the moteino, battery connection or something, so I tried again and saw the exact same result. This time I just waited, and sure enough, 1 minute later, the power jumps to 5 or 6mA for a second, then back to 0.000 on the meter. The radio transmitted as I see the updates in my database.
I have done this now three times, with 4 x AA Lithium, 2 x AA Lithium, and 2 X AA Duracell and only with the duracell (at a lower voltage) does the power go to zero (or as low as my meter will read) between transmits. If I use a higher voltage or lithium batteries, the power stays constant at 5mA until transmit, jumps to 13mA for a second then back to 5mA.
I thought the higher the voltage, the lower the amperage, and I m at a total loss as to why lithium batteries (or I assume more correctly a higher voltage) would result in a constant current draw on the moteino (exact same sketch on all tests) and tested on three moteinos.
Can you help me with what Im missing?