I've been experimenting with one of these modules for a while now but I waste a lot of time getting caught out by undocumented limitations. I was hoping people would share their observations and any tips that may save some time.
As an example, it's documented to allow a delay of 40ms to enter command mode, and 80ms to exit command mode. But it isn't documented that any delay needs to be provided between receiving "OK+SLEEP" and setting HSET=1. However if I don't leave a ~10ms delay the module doesn't properly go to sleep, evident from the ~1mA consumption, cf. ~22uA when asleep.
Also, the 40ms and 80ms are not a function of the mode according to the datasheet. But these are very long delays which significantly increase the power consumption in my use case. Does anyone know if you can safely trim these times in FU1 mode?
This is the best version of the datasheet I've seen
http://statics3.seeedstudio.com/assets/file/bazaar/product/HC-12_english_datasheets.pdf
As an example, it's documented to allow a delay of 40ms to enter command mode, and 80ms to exit command mode. But it isn't documented that any delay needs to be provided between receiving "OK+SLEEP" and setting HSET=1. However if I don't leave a ~10ms delay the module doesn't properly go to sleep, evident from the ~1mA consumption, cf. ~22uA when asleep.
Also, the 40ms and 80ms are not a function of the mode according to the datasheet. But these are very long delays which significantly increase the power consumption in my use case. Does anyone know if you can safely trim these times in FU1 mode?
This is the best version of the datasheet I've seen
http://statics3.seeedstudio.com/assets/file/bazaar/product/HC-12_english_datasheets.pdf