I've got a pair of remote control cars but only have a single transmitter. Rather than buy a sketchy used one off of eBay I was hoping to create one from scratch. I found a schematic for it but I'm certain it could be improved, so I was hoping for some advice; I am completely RF-illiterate.
The IC/encoder block appears to be
loosely based on the Pericom PT8A995 or something like that, since the receiver circuit on the cars uses a Pericom PT8A201W. I don't think this will be much trouble to recreate on a more "standard" microcontroller.
What I see beyond that on the schematic is...
- basic input mux stuff (like any remote control), plus steering angle and speed offset controls
- reverse polarity protection diode
- zener diode voltage regulator for IC
...and that's about it. Rather than blindly copy the schematic without fully understanding it I was hoping somebody could let me know of any alterations I may need to make, etc.
The main concerns I have are:
- If I use a 5V regulator and IC (instead of the 3.6V one in the schematic) will I need to adjust the values of any passives in the Q4 area?
- Similarly, if I remove the reverse polarity diode (e.g. use a polarized connector or NPN MOSFET), will any of the passives around Q1/Q2/Q3 need to be adjusted for the ~0.7V higher voltage?
- Is there anything obvious in the schematic that is limiting the output power? The range of the transmitter I have is fairly short...
Thanks!