Arduino Clock speed possible issues...

[brad.s]

First off, Im new to this forum and look forward to participating. I have been planning to make my first arduino sensor network for some time and have been researching constantly. I already have an Arduino uno with its W5100 based ethernet shield. I was looking to buy some arduino pro minis to act as sensor nodes. The question I have is since I plan to use the uno with its ethernet shield as the MQTT gateway does it matter what version of the Arduino pro mini I buy? I know the Uno has a 16MHz clock whereas the 3.3V arduino pro mini has a 8MHz clock. Does this make a difference in the overall communication on the network? Would it be better to get the 5V pro minis with a matching 16MHz clock instead? Thanks.

[BulldogLowell]

@brad.s

The transceivers communicate via RF via an embedded hardware protocol. The micro-controller communicates with the transceiver module using (standard) serial communication.

Good radio communication and buffering of incoming or outgoing messages are more-or-less unaffected by clock speed of the micro-controller. So, it is not necessary to match clock speeds.

The clock speed may affect energy consumption so you will want to optimize your arduino model for its sensor application and choice of using battery or mains power. Also, your choice of 5V or 3V3 IO will affect your sensor build strategy, having to power up or down to accommodate the IO requirements of the attached devices (e.g. radio transceiver 3.3V or a pressure sensor at 5V).

Available SRAM/FLASH memory is also a factor, if you want to get into more complex devices later on.