Hi All,
I have an application where I need very short range data transmission (up to 2cm).
Any higher and this adds too much complexity and cost to the project due to many identical objects in very close vicinity of each other.
Originally this was going to be designed using IR for a two way link but the project must be waterproof.
I was thinking of both the master device and slave devices having a electromagnet for the transmitter and a hall effect sensor for the receiver.
The RX and TX are far enough apart (10cm) to not interfere with each other.
Each side will have a pair of transmitters and receivers - this is to allow for multiple orientation - using neodymium magnets to help with alignment.
having a pair of channels also allows for a unconventional SPI comms.
Master TX1 -> Slave RX1 = Master controlled CS (Master will have multiple slaves)
Master TX2 -> Slave RX2 = MOSI data
Master RX1 <- Slave TX1 = Slave Generated Data Clock (unconventional but allows for multiple orientation)
Master RX2 <- Slave TX2 = MISO data
The data rate can be low - as low as 1200bps (or less) as there will only be about 30 bytes per transmission and only 1 transmission per second.
My questions are...will this work?
What range does a hall effect sensor have?
Are small SMD inductors capable of producing enough magnetism for the sensors to pick up - through waterproof material?
Will an inductor hold magnetic charge and prevent data style pulses from being read?
