I'm working with a device that allows remote updates via SNMP to change the FM input/ouput frequency of the device. When I query the devices, I get back whole numbers, but, in real life, FM frequencies have decimal values. I happened to stumble across some code for setting the frequency where the developer was taking decimal values (representing FM frequencies) and dividing them by 0.05 before saving them into the device. Inversely, for display purposes, the developer multiplied the numbers by 0.05 to turn them back into their decimal notation. For example:
107.1 / 0.05 = 2142 2142 * 0.05 = 107.1
There is no documentation that specifies the meaning of this operation. I thought it might be some kind of fixed-point arithmetic (popular before the days of FPUs, but I wasn't sure because I thought fixed-point arithmetic usually stuck to base 10 or base 2.
Is anybody able to explain this operation? Is my suspicion correct?