What is the cheapest way of developing a Z-wave sensor, hopefully that doesn't require me to buy the Sigma development kit nor the expensive API licence, nor the expensive Keil compiler. Ideally I would like to base it on the Sigma ZM5101 chip rather than a board like the Z-Uno. It seems to me that a temperature sensor could be designed with very few components beyond the ZM5101, the DS18B20, and a 3V lithium cell. This could be very small, and have a decent battery life, if one didn't measure the temperature too often. Why do they insist on people using the Keil IDE? Surely it must be possible to convert the code so that it will build in a free tool chain?
Thanks - Rowan