I'm looking for low-power RF solution working in sub 1GHz band (868MHz, battery powered, mostly sleeping). Originally I considered AVR with Digi Xbee 868LP module but doing deeper research I found TI RF solutions. TI offers open source SimpliciTI protocol implementing star wireless topology. Which is not as originally supposed mesh topology but it's simpler and has shorter packet time-to-delivery than multi-hop network (advantage for MODBUS). 868MHz range should be sufficient without multi-hopping and in the worst case even range extender is available, price is convenient as well. RF packet sniffer seems as good debugging tool, completely missing in Xbee.
MCU MSP43x + RF module CC1100
MSP is ARM Cortex M3/M4 MCU which offers many variants (including more friendly non-QFN socket) as it is standalone MCU. A certified module CC1100 might be used, e.g. Anaren, to shorten time-to-market and avoid RF issues. Seems besides paid (for-free as crippleware) development tools (CCStudio, IAR) does exist GNU GCC for MSP. It should implement in-system debugging via GDB with MSP-FET. There is also open source Energia project, but authors present it as equivalent of Arduino IDE (which is useless for serious devel so I doubt about Energia).
CC1110 MCU+RF (SimpleLink)
There is not ARM but 8051 core. Seems as low cost solution to implement remote sonsors and control based on SimpliciIT. TI offers evaluation boards including CCDebugger but I cannot find info if does exist a free toolchain. Bundled with crippled IAR EW8051 IDE. Probably missing EnergyTrace power consumption monitor (only MSP feature).
Similar as CC1110 but Cortex M3. I'm afraid it's slideware.
Does anybody get working CC1110 with GCC including full in-system debugging ? Are my findings correct?