nRF24L01 wireless 2.4GHz transceiver SPI module, small form-factor, low power consumption and good time-sync. Practical minimum quantity to purchase: 2 pieces
2MBps physical speed.
Max net throughput appr 1.2MBps in one direction because of framing, and depending on signal strength (and signal to noise ratio) of course.
Subtract some dead time for each direction change, for the TX=>RX TX<=RX role swap.
In other words, for a 1 MBps full duplex link 4 modules are needed (using 2 different radio frequencies).
127 channels selectable, some are in typically silent band, slightly above typical wifi frequencies.
Note: because of it's low power consumption for operation, and sub μA power down mode, very suitable for battery operation (for remote sensing/actuation).
Note: besides the SPI (SCK,MISO,MOSI, CS interface) nRF24L01 features an interrupt output line, which can signal the time of incoming packet
(fired when correct frame received with proper CRC). According to our information, this is very precise (no CPU processing related jitter), hardware actuated 62nsec (16MHz <20 light-meters). Very good timesync is possible between stationary modules (especially with some averaging, but even without), or time of flight measurement for mobile nodes. According to our information similar is not available for off-the-shelf commercial (non-military or secret-intelligence) wifi, bluetooth or zigbee modules.
Note: just to mention a possible application, it is possible to implement a garage-door remote control with certainly good jumping code system, no backdoor, or replay-voila that cannot be ruled out with non-programmable (factory programmed) off-the-shelf gadgets. Can be great accessory in a poor-man's ILS for automated landing of drones, or other robot-systems.
Not currently integrated with VEMS devices. It is for hardware hackers / tinkerers.
Provided AS-IS (we might test them, or send as received). We don't have comparison /test results with other similar modules (eg. max distance under certain circumstances).
Nordic Semiconductor datasheet and examples on internet to find out how to connect to your processor and program it. No return for any reason.