drvegetable
May 11, 2007, 07:15 PM
I'm trying to modify an inexpensive 27MHz transmitter to provide variable turn ratios and low speed steps for the AeroAce (as others have done) using a PIC to generate the PPM signals. I was looking at tapping into the RF section of the AA remote. But then I took a look at the remote for the $20 "FastLane RC Arrow" and thought it might make a better platform for this mod. Longer throw on the sticks, more room inside the cabinet, and the RF circuit looks like it can be easily separated from the controller.
It looks as if the logic for generating the control signals for the Arrow is contained on a daughterboard that is attached to the throttle lever. The steering lever (a pair of switches) is wired directly to the daughterboard, and the entire control stick assembly is connected to the main transmitter board by three wires. (Power, ground, and signal???) It looks as if a new control section can be tapped into this radio by removing these lines and replacing the daughterboard with a PIC circuit...?
I'm poking around and figuring the circuit out slowly, but thought maybe somebody else might already have done so. Has anybody tried to hack this transmitter yet?
Edit:
So it looks like this is proving out. The three wires are ground (grey), +2V (purple) and control signal (blue). There is a micro buried beneath a blob of goop on the throttle stick daughterboard that puts +2V into R17 and through Q4 (both on the daughterboard) and then into the blue wire back to the RF section. There is a convenient test pad on the daughterboard right beside R17 that looks like a good place to inject a new control signal. (Probably need to cut the trace between the micro and this test pad.) The circuit looks very similar to the one in the AeroAce, right down to the component names, even though the board layout is completely different.
So this looks to be a very hack-able transmitter. By the way, the FastLane RC Arrow is the same airplane as the Silverlit Singlewing, one of the most-hacked models on this forum.
It looks as if the logic for generating the control signals for the Arrow is contained on a daughterboard that is attached to the throttle lever. The steering lever (a pair of switches) is wired directly to the daughterboard, and the entire control stick assembly is connected to the main transmitter board by three wires. (Power, ground, and signal???) It looks as if a new control section can be tapped into this radio by removing these lines and replacing the daughterboard with a PIC circuit...?
I'm poking around and figuring the circuit out slowly, but thought maybe somebody else might already have done so. Has anybody tried to hack this transmitter yet?
Edit:
So it looks like this is proving out. The three wires are ground (grey), +2V (purple) and control signal (blue). There is a micro buried beneath a blob of goop on the throttle stick daughterboard that puts +2V into R17 and through Q4 (both on the daughterboard) and then into the blue wire back to the RF section. There is a convenient test pad on the daughterboard right beside R17 that looks like a good place to inject a new control signal. (Probably need to cut the trace between the micro and this test pad.) The circuit looks very similar to the one in the AeroAce, right down to the component names, even though the board layout is completely different.
So this looks to be a very hack-able transmitter. By the way, the FastLane RC Arrow is the same airplane as the Silverlit Singlewing, one of the most-hacked models on this forum.