Ultimately what I want is a clean solution that allows me to control a sweet Losi or other high quality brand RC car from my PC. I'm a software developer so I should be able to write the PC app code myself. The challenge for me is how to provision a radio transmitter for my PC. I didn't find any PC peripherals that would suffice so I figure this is something I need to build myself.
I see plenty of examples of folks wiring arduino devices up to existing controllers and/or RC cars however I have yet to see any examples of use of arduino to control an unmodified brand RC car without use of the shipped RC controller. I have seen examples that use the NRF24L01+ transceiver module to communicate with other modules of this type. But can this module be used to generate the necessary radio waves to simulate one of these nice brand vendor RC controllers?
The RC world has evolved a series of incompatible spread spectrum or frequency hopping protocols designed to maximise the chance that some percentage of the packets make it to the destination with minimal latency. Data loss is expected and the receivers are designed to cope with this. There's no retry mechanism as the data in a packet is only 'valid' for a few milliseconds.
The simplest option is to generate a PWM signal in 'buddy box' format and feed that to the RC transmitter that came with the car. If you want a challenge then buy one of the chips that supports the protocol used by your car.
This is an incomplete list.
Micro Linear ML2724 used by Futaba FASST.
Cypress CRYF6936 used by JR/Spektrum’s DSM, DSM2, DSMX.
Texas Instruments CC2500 used by HiTec, Co-rona, FrSky, Tactic, Futaba S-FHSS.
Texas Instruments CC2520 used for JR's DMSS.
AMICCOM A7105 used in Turnigy 9x/FlySky/HobbyKing.
The transceivers you typically see mentioned in the Arduino context are optimised for a low power consumption or attempt to reliably transmit data at the expense of latency.