@andriej
Hi, I had problem using the main branch mysensors/Raspberry, that because of the bit-field struct (header_s) in Sensor.h They will get packed in different order on the arduino compared to the RPi (at least with my compiler, gcc). In order to fix this I created the 1.4dev branch. It uses full bytes instead of the bit-fields, but you need (of cause) to compile both the sensors (arduino) and the gateway (RPi) using the 1.4dev branch.
We need to fix this in the main branch later on (and use the same files as in mysensors/Arduino/libraries/MySensors)
It has been a long time but I’ve learned a few things that I wanted to share.
This library of information (Thank you NeverDie and others) has been so helpful in my hobby developments.
Software Defined Radios for signal analysis. With the help of Andreas Spiess explanation of IQ transformations, I learned about Software Defined Radios and I bought one (RTL-SDR). Using this I can clearly discriminate between effective 433 MHz transmitters and bad ones. Not only is the signal density displayed on the software (SDR#) but so is the frequency.
Power Profiler Kit II has been indispensable in watching power usage and seeing into the details of the radio transmission. In effect this thing has saved me from buying an oscilloscope for my simple little bench.
Tonight, I saw this video: https://www.youtube.com/watch?v=Z9nycymUd-I It describes common PCB errors. It is too advanced for me, but I did pick-up a few ideas about ground planes (tip #6 from the video).
I hope this is of some value for folks.
Of possible interest: Here's a guy who is building an inexpensive open source ethernet controller for stepper motors:
What happend to Ethersweep? Project Update! – 12:36— Neumi
If you listen to the end, it's revealed that there is now generous funding available which allows people to do this kind of open-source development as a full time job, which is what he is now doing. For that reason, I think there's a good chance he will complete his project within the allowed 6 months., and so by the deadline it will likely be nicely polished.
Some humidity sensors are known to lose accuracy with age. For instance, the Si7021 is known to have this problem. If that matters to you, then the best choice is to pick sensors that have datasheets and which have specs as to their expected longevity or accuracy over time. Then buy from mouser/digikey to be certain you're getting the real thing rather than factory rejects or counterfeits.
For extra insurance, I avoid electrolytic capacitors entirely whenever possible. I buy only 7XR rated ceramic capacitors that are overspec'd. The difference in price is small compared to a failure down the road.