RC ringing input to BS2?
garyg
Posts: 420
I'm attempting to connect my BEC radio control receiver to my BS2 Homework board.
I originally used the BEC rc receiver to control the servos on my RC boat.
I've been able to control my Scarecrow 3 wheeled platform via the boat radio and receiver quite well.
I now am attempting to make my Scarecrow platform run by itself.
My plan is this.
Connect the signal pins from the BEC receiver as inputs to my BS2 Homework board.
Connect the ground pin from my BEC receiver to the VSS pin of the BS2 Homework board.
In my research using various Parallax document info and searching on the internet, the only
thing that I've found concerns Ringing of the input signal going from the BEC receiver to my BS2 Homework board.
According to the internet info, the load that is seen by the Radio control receiver needs to be somehow matched
the input of the BS2.
To control the potential ringing of input signal to the BS2, would connecting something like a 10K resistor From the
input pin of BS2 to Vss help to stabilize my input signal?
I hope I'm realizing correctly that when a BS2 pin is set to input, it becomes a very high resistance and as long
as the voltage going from the rc receiver output is within 5 Volts or so I will not destroy my BS2 controller.
The end game here is to use my RC radio to send signals to the BS2, which will scale the input values and output
my steering and speed control values.
Using the RC radio, I should then be able to tell my Scarecrow platform to either run without help or be controlled by
my RC radio.
Any thoughts or suggestions are greatly appreciated.
Thanks
I originally used the BEC rc receiver to control the servos on my RC boat.
I've been able to control my Scarecrow 3 wheeled platform via the boat radio and receiver quite well.
I now am attempting to make my Scarecrow platform run by itself.
My plan is this.
Connect the signal pins from the BEC receiver as inputs to my BS2 Homework board.
Connect the ground pin from my BEC receiver to the VSS pin of the BS2 Homework board.
In my research using various Parallax document info and searching on the internet, the only
thing that I've found concerns Ringing of the input signal going from the BEC receiver to my BS2 Homework board.
According to the internet info, the load that is seen by the Radio control receiver needs to be somehow matched
the input of the BS2.
To control the potential ringing of input signal to the BS2, would connecting something like a 10K resistor From the
input pin of BS2 to Vss help to stabilize my input signal?
I hope I'm realizing correctly that when a BS2 pin is set to input, it becomes a very high resistance and as long
as the voltage going from the rc receiver output is within 5 Volts or so I will not destroy my BS2 controller.
The end game here is to use my RC radio to send signals to the BS2, which will scale the input values and output
my steering and speed control values.
Using the RC radio, I should then be able to tell my Scarecrow platform to either run without help or be controlled by
my RC radio.
Any thoughts or suggestions are greatly appreciated.
Thanks
Comments
It sounds like you have it hooked up to the BS2 correctly. How is the receiver being powered? What is happening or not happening with the way you have it hooked up now?
If you wish, you can load the servo signal with a 10K-15K resistor. Make sure the receiver ground and Stamp ground are tied together. The servo-signal wire from the receiver goes to the Stamp input pin.
http://www.youtube.com/watch?v=6opeJXWy2vY&feature=g-hist
http://www.youtube.com/watch?v=kwCO6wMgRm4&feature=g-hist
these might help
It appears that I'm thinking correctly.
I'm always concerned when trying something new, that I will somehow create a short circuit condition or
over voltage condition that will ruin my project.
I've attached a photo of my BEC receiver and JR radio.
I would think that my receiver and radio are quite old.
I think that the BEC printed on my receiver has to do with the fact that BEC's were more than likely
new at the time my receiver was manufactured.
I'll write a simple program for my BS2 that will use PULSIN to see if the input signal is stabil.
If this works, I can proceed with developing my platform control.
I believe that my concerns over Ringing input signals from my RC receiver to my BS2 were unfounded.
The system works, as far as I can tell, without any problem.
After connecting my RC receiver into my system the numbers that were output when using the PULSIN command
and a DEBUG routine were very consistent without any numbers jittering.
My test setup was done by using a voltage divider consisting of 2200ohm and 10Kohm resistors connected in series to VSS,gnd
The signal from the RC receiver was connected to the 2.2K resistor.
I did this because I did not want the stamp to see more than 5V at the input pin.
The input to my Basic stamp was connected to the 10K resistor.
I believe that the Voltage divider minimized the current draw by my RC receiver circuit and reduced the maximum voltage that the
Stamp would see, so that I can use 4.8V from my 4 AA rechargable batteries or 6V from 4 regular non rechargable batteries
to power the RC Receiver.