I'm just looking at the DW manual pages 27-32. It looks pretty informative, but on the other hand I don't actually understand it. I wondered if you do?
p28 it says that if we found some way to turn the DW power off then it would consume zero, and would take no longer to start up than if it were in deepsleep (50nA) or sleep(1uA). The downside of "off" is that it would be necessary to reload all the configuration – which is a bunch of SPI activity, so the tradeoff depends on the time between wakeups. In a footnote it says the osc. startup delay is 3ms.
But on p29 the sleep currents are all doubled? Does that mean they are assukming a 2s sleep? If so, why? It also says there is a 5ms osc. startup delay.
On p30 there is a table of TX range vs. current. All the ranges are in access of 40 meters which seems plenty for our needs, but I wonder if the range will be attenuated indoors? I expects so.
The best ranges (in descending order) are in modes 10,12,14, 2, 5. The TX powers are ~36,38,28,34,34 mA (reading from the range graph). But the table at the top of the page says 79,75,65,68,50mA (for channel2) and slightly more for channel #5. Why the difference?
And then the chart on p31 profiles a complete transmission, and the figures are not consistent yet again.
OSC startup/PLL lock takes 2.007ms (not 5ms).
And in any case, is the total power used on p31
| mA | W @ 3.3V | duration us | uW seconds |
| 3 | 0.0099 | 2000 | 19.8 |
| 12 | 0.0396 | 7 | 0.2772 |
| 15 | 0.0495 | 10 | 0.495 |
| 65 | 0.2145 | 135 | 28.9575 |
| 48 | 0.1584 | 16 | 2.5344 |
| uJ | 52.0641 |
So 52uJ per transmit? How many uJ do we have in our battery?
//Mik