Hi all, new to working with the imp, i have a question for Joel Wehr or anyone who has used IOT Buddy or similar or infact anyone that knows how to do this. I want make pin 1 to HIGH when I press button 1 and then pin 1 to LOW when I press button 1 again, so the button turns into an on/off switch basicly, how is that done? I know i can use button 2 as an off switch but I need that button for something else.
This is the very basic code I have just for pin 1, I’ve given pin 1 a 5 second timer but I really do not want that to happen, would much rather toggle between high and low from one button:
function set(value) {
if value ==1 {
hardware.pin1.write(1);
imp.sleep(5.0);
hardware.pin1.write(0);
}
I guess I would use a global to hold the state of the thing that was being switched.
state <- 0; function set(value) { if value ==1 { if (state == 0) { hardware.pin1.write(1); state = 1; } else if (state == 1) { hardware.pin1.write(0); state = 0; } } }
If you want to look at a more complex example, the code I use for the security system and garage door opener with my Pitchfork app actually hold the state of the system and can retrieve it back to the app. I keep track of state in the agent and in the device.
If you have some kind of physical button (momentary), you probably will need to de-bounce it so you don’t get multiple changes on one push.
Another way to change the value is to simply use XOR to change the state.
Start out with the global variable … state <- 0;
Here is how XOR logic works …
XOR = “one or the other but not both”.
If it’s 0 (OFF), and you XOR it with a 1, it will be 1 (ON)
If it’s 1 (ON), and you XOR it with a 1, it will be 0 (OFF)
Here is the line for XOR … state=value ^ state;
I actually didn’t test it, but to me it looks like it should work.
If you’re just flipping the state of a DIGITAL_OUT pin, you actually don’t need a state variable. If you do a pin.read() on a DIGITAL_OUT pin, it will return whether it’s currently being driven high or low.
That takes me way back to assembly languages where the programmer tries to conserve every byte and every clock cycle. It’s way more fun to do it with 10 lines of code though :>
Hi everyone, this is Musa, the guy who originally posted this discussion, had to change accounts as my old one wasn’t working for some reason. I’m waiting for our product designers to finish our prototype and solder on an April board so I haven’t been able to try the code that was given above and I won’t be able to for at least another 2 weeks. In the mean time I thought i’d attempt to write the code without our prototype and simply try it once it has arrived.
While the code given by Bearded Inventor looks great, its simply too complex for a programming novice like me. Joel Wehr’s example with a global looked a bit easier for me so I went with that route.
Before I show my example code I want to clarify a few things. The project is a DC motor soldered to a rf receiver and motor controller. The April board is connected to a 1 channel rf transmitter that can make the motor rotate clockwise or anti clockwise. (yes we can attach an April board directly to the motor controller, but we have to do it this way for reasons I can’t explain). I’m using Joel Wehr’s Iot Buddy to controll the motor from my smartphone, button one (value 1) moves the motor clockwise and pressing button one again stops the motor, button 2 (value 2) moves the motor anti clockwise and stops stops once its pressed again. Pin 1 is connected to the clockwise input of the transmitter and pin 2 the anti clockwise. And of course I got my URL by adding an “HTTP IN” from the Electric Imp Planner. Here’s the code I’ve written, please let me know if I’ve done something wrong or if it could be improved.
Class input extends InputPort
{
name = "Motor Controller"
type = "Number"
state < - 0 ;
function set(value) {
if value ==1 {
if (state == 0) {
hardware.pin1.write(1);
state = 1;
}
else if (state == 1) {
hardware.pin1.write(0);
state = 0;
}
if value ==2 {
if (state == 0) {
hardware.pin2.write(1);
state = 1;
}
else if (state == 1) {
hardware.pin2.write(0);
state = 0;
}
}
}
hardware.pin1.configure(DIGITAL_OUT);
hardware.pin1.write(0);
hardware.pin2.configure(DIGITAL_OUT);
hardware.pin2.write(0);
imp.configure(“IoT Buddy”, [input( )], [ ]);
Please let me know if there are any foreseeable faults, and be gentle I’m a complete novice at programming. Thanks in advance.
Now that the planner has been officially retired, I would encourage you to download and use my other app, Pitchfork to control this device (It’s free). Pitchfork sends JSON data, which is just a table of key:value pairs. For example, if you assign the value “on” to Button 1, it will pass this pair: “button1”:“on”. It is really easy to parse that out in the agent, and I have example code that you can use.
If you use this code the way it is, you don’t even have to enter a value for the buttons if you dont want to. You can just modify the each button handler in the device code. Maybe set up three buttons instead, and have a clockwise, stop, and counterclockwise button? In the code below, button 1 would turn one way, button 2, would stop it from turning either way, and button 3, would turn it the other way.
agent.on("button1", function(a) { local data = ""; if (a == "") { hardware.pin1.write(1); data = "Button 1 pressed."; } agent.send("button1", data) }); agent.on("button2", function(a) { local data = ""; if (a == "") { hardware.pin1.write(0); hardware.pin2.write(0); data = "Button 2 pressed."; } agent.send("button2", data) }); agent.on("button3", function(a) { local data = ""; if (a == "") { hardware.pin2.write(1); data = "Button 3 pressed."; } agent.send("button3", data) });
As much as I would like to, I’d have to learn how to use Eclipse, and program in Java.I realize that there are more android IoT users, but I’m going to stick with iOS for now, as I have invested a decent amount of time into it. (And I just got an iPhone 5S)
ahhhh Crud! had no idea planner had retired. Thanks Joel and yes looks like I will have to use pitchfork and thanks for the code, I’m guessing that’s the agent code, any chance you can show me what the device code would be? Sorry to be a pain but I honestly have no idea how to use agents or JSON data.
Full code for agent and device are on the GitHub page that I posted. The code that posted above is just a suggestion based on what you are doing.
Can your motor controller PWM the motor, or is it just on and off? I’m trying to set up the Pitchfork control panel to work well with bots, drones ect.
OK I’ll have a look, no the controller doesn’t use PWM just a simple on and off with transistors I believe. The hardware guys told me that the programme has to make pins 1 and 2 HIGH and LOW when requested by the app.
It isn’t necessary, it’s just an extra bit of security. You set the API-Key in the Control Panel settings page, with the rest of the settings. You can leave them both blank, or take the line out of the agent code that checks for it, or just enter a simple key in both. It is practically zero effort for a whole extra layer of security.
