Well, this morning has been a long discussion about microcontrollers. There are several good options:

• Arduino with the Adafruit BLE breakout board and a CC1200 transceiver
• RFDuino with onboard BLE and a CC1200 transceiver
• MSP430 SoC with onboard transceiver and the Adafruit BLE breakout board
• MSP430 SoC with onboard transceiver and a Nordic nRF8001 on a custom board

The MSP430 options will take significantly more time to design, since a custom PCB will have to be laid out, sent off for manufacturing, tested, etc. However, that's true even for the Arduino family chips, since the CC1200 needs a breakout board, and I haven't found any.

If we use the Adafruit BLE board, we're limited to ASCII/UART transmission and reception, and I haven't seen detailed information on whether the peripheral has any control over the pairing process. Using the nRF8001 chip on our own board should give us complete control over the entire process and more options for data transmission but again, the tradeoff will be in development time.

If we ditch the sub-1GHz transceiver portion of the project and use only an RFDuino, everything gets much easier...but nothing worth doing was ever easy, right?

Since the system design document must be completed by the deadline tonight (in...15 hours and 11 minutes), we have to choose our components quickly. Compromise isn't a bad thing, but unless it achieves a goal it's pointless. Therefore, I've narrowed it down to two options:

• RFDuino with onboard BLE, without an independent RF transceiver
• MSP430 SoC with onboard transceiver and a Nordic nRF8001 on a custom PCB

This project may seem on the surface to be about devices, but in reality it revolves around creating a distributed, fault tolerant messaging network. If we develop a functional, useful system design that others can build on, but our proof of concept devices are lacking in their implementation, that will not be a failure of the project as a whole, and leaves the door open for further development as time permits. (It may not seem like it today, but we do have day jobs)

With that in mind, especially since the two options I have are both excellent options in some ways and challenging in others, I'm going to take the coward's way out and choose both. The system design document will incorporate both builds, and everything but the core system board will be the same for both devices (battery, power supply, case, solar panel, etc).

The RFDuino build will almost certainly be completed first, but PCB design, layout and manufacturing for the MSP430 system will be concurrently worked. This makes a proof of concept device contingent only upon our coding chops, but still leaves the door open for a more full featured custom build if our hardware skills are up to the task and the manufacturing gods smile down on us.