I found something really cool recently and that is you can open electronic devices and basically use external voltage of the same logic level to fool the program into thinking that another component of the device has given it input...In this way you don't need to deal with the programming and can just use the voltage to activate the logic...
I don't know too much about how this works but I saw the project and really liked it..The Nitendo DS used a logic level of 1.8 V so I am guessing the guy used "something" to step-down arduino's 5v logic to 1.8v. Now from what I vaguely understand....you can't just hook up 1.8V to the input and fool the machine into thinking the proper logic has been activated....You have to send a pulse of a special time width with the given logic voltage (1.8 V in this case) to get the machine to be fooled. I want to use this same idea to modify my rc radio remote so I can use arduino and my computer keyboard to fly it instead of using the remote...I really don't know though what I need to "fool" the machine..I can use a digital multimeter and measure what the voltage is accross the joysticks when pot is at 0 and so I can find out what level of logic (voltage) the radio operates on but then how do I know what the time the pulse should be and how do I create a timed pulse? Basically, I LOVE this whole idea but I don't know what tools or things I need to start playing with the logic of electronic devices using electricity...
Can someone help me with that? Also as a side question, if my device's logic level is lower or higher than the arduino, how can I make it so that the logic level of arduino can be shifted to match the device's logic level? Thank you so much! How can this guy get the flash in light level so accurate to the millisecond? Is the arduino really capable of doing that? Wouldn't there be a time delay between arduino processing the code and the sensor reading the values? This would make it really hard to know what the exact millisecond length is that the screen flashes for at normal pokemon and then the shiny pokemon..Would he have played with the sensor attached until he found the shiny one to know what the overall average length is of the flashing?
Once I know how this whole logic manipulation works using hardware I could buy a cheap computer and rip out the keyboard keys to solder wires onto each key and manipulate the computer using Arduino!!
You would use a level shifter to interface two digital devices that work on different logic level voltages.
How you generate the signal for your RC system would depend which part of the system you intend to replace with the Arduino. Usually you would have a transmitter which generated a wireless signal, and a receiver which detected that wireless signal and generated a set of servo control signals, and servos receiving the servo control signals. Which part of that are you trying to replace with the Arduino?
If you want your Arduino to send keyboard events to your PC then you can do that by making your Arduino emulate a keyboard - you don't need to hack up a physical keyboard.
Thank you Peter. I was thinking of removing the joysticks which control the height and direction of the RC copter. I don't really care so much about the project itself but I am trying to learn how you manipulate the logic. How can I know what the logic level is of those joysticks and do I also need to find out what the length of the time pulse is that the joystick's logic sends to the MCU which transmits the instructions to the receiver? Basically what is it that I need from a hardware perspective to start replacing a joystick by the Arduino? I read online that you can put some program onto Arduino and that makes it a logic analzer so I don't need to go buy one but how do I find out what the logic level voltage and time of the pulse is that the joystick sends to the MCU and how would I get the arduino to simulate this? From your reaction it seems to me like it is easier to simulate a button rather than a potentiometer.
Basically, the joysticks are sticks on a remote which are connected to potentiometer and the MCU uses the pot values to transmit instruction to the receiver which in turn controls the servos. I want to learn how you start this whole process of analyzing the logic and replacing pots + buttons with arduino.
The joysticks are typically used to drive rotary potentiometers which are connected to electronic circuits that generate the RF signal. If you want to, perhaps you could replace them with digital pots that the Arduino could control. Some RC transmitters provide a 'training' option where they can receive an input signal from a second handset. Typically that signal takes the form of a digital signal that the Arduino can generate quite easily. If your transmitter supports that interface it would make your project easier.
My plan was to use the digital pot for this just like you said. I am just trying to figure out how to manipulate the logic like that person with the nitendo DS did. I am using the project as an example (probably a bad example) and I am only interested on how he manipulated the logic using the arduino.
Say I have a gameboy and I want to simulate the buttons using the arduino then how can I find out the:
a) logic level gameboy operates on
b) the width of time pulse I need to send
c) how to do it with an arduino uno
Ok...So from what I gather it doesn't matter how long the 5 V input from Arduino is on for when simulation a button..All you need a 5 V on and then off with a level shifter that works for the gameboy logic level. I thought that the time the button is down for mattered but after thinking about it, I don't believe the time will matter. With this I could just send 5 V -> level shifter -> game boy button and then cut the 5 V off and that equals 1 button press. So the only thing really ingenious about that gameboy is the level shifting from arduino to gameboy logic level and the fact he used a photo-transistor....If someone understands what I just wrote then verify what I understand is correct or incorrect.