A is the voltage I want to keep (it indicates the button I need to press)
B is the voltage that I don't need
How do I make it so if the button I need is clicked a led will be turned on?
int smooth(int sensor){
int i;
int value = 0;
int numReadings = 10;
for (i = 0; i < numReadings; i++){
// Read light sensor data.
value = value + analogRead(sensor);
// 1ms pause adds more stability between reads.
delay(1);
}
// Take an average of all the readings.
value = value / numReadings;
// Scale to 8 bits (0 - 255).
value = value / 4;
return value;
}
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
}
void loop() {
// put your main code here, to run repeatedly:
int smootha = map(smooth(A1),0, 307, 2, 150);
Serial.println(smootha);
delay(1);
}
if someone could help me to filter it right and get only the A voltage (like) state I'll be thankful so much!
Is that really 43 volts (with a voltage divider?) or are those the raw readings?
Why are you scaling down to 8-bits? You're throwing-away resolution.
It's also not clear what you're doing with map() which is also throwing-away resolution.
And, your main loop does the same thing over-and-over with the same-old data...
And what's the time scale? You might be making it worse (harder to detect) by smoothing/averaging. You need to look for the "positive" and "negative" peaks.
The logic doesn't seem too hard - A goes above and below the nominal and B only goes above the nominal. Anything below nominal (by a certain amount) is A (and then you don't need to check if it's going above).
If it's not below nominal, you can check if it's above (by a certain amount), and if so you've got B.
The only thing is, it doesn't go much above nominal (as a percentage), maybe about 5%, so hopefully the nominal voltage is very-stable.
DVDdoug:
Is that really 43 volts (with a voltage divider?) or are those the raw readings?
Why are you scaling down to 8-bits? You're throwing-away resolution.
It's also not clear what you're doing with map() which is also throwing-away resolution.
And, your main loop does the same thing over-and-over with the same-old data...
And what's the time scale? You might be making it worse (harder to detect) by smoothing/averaging. You need to look for the "positive" and "negative" peaks.
The logic doesn't seem too hard - A goes above and below the nominal and B only goes above the nominal. Anything below nominal (by a certain amount) is A (and then you don't need to check if it's going above).
If it's not below nominal, you can check if it's above (by a certain amount), and if so you've got B.
The only thing is, it doesn't go much above nominal (as a percentage), maybe about 5%, so hopefully the nominal voltage is very-stable.
No, I got a calculator that I want to hack, and theres terminals for every column and row, and as I connected the third row, when I click a button that isn't in the third row it shows me the B signal and if I click a button in the third row it gives me A signal
What voltage are you sensing? Not the column or row lines? You are seeing a tiny analog voltage variation,
suggesting you are monitoring the power rail only.
MarkT:
What voltage are you sensing? Not the column or row lines? You are seeing a tiny analog voltage variation,
suggesting you are monitoring the power rail only.
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Tom...
I can't make a circuit for this because it contains a device I can't import to the cad
just imagine that,
GND of the arduino to the GND of the calculator's battery
VIN of the arduino to the (+) terminal of the calculator's battery
A0 of the arduino to the K02(second column) of the calculator
mlirang:
No, I got a calculator that I want to hack, and theres terminals for every column and row, and as I connected the third row, when I click a button that isn't in the third row it shows me the B signal and if I click a button in the third row it gives me A signal
You need to look at the all the column and row terminals individually, the keypad is multiplexed so you cannot just look with a single connection.
How the calculators keypad is multiplexed will make it difficult for you to read, as you do not have control of the calculators multiplexer to sync any readings you take.
Tom...
void loop() {
int sensorValue = analogRead(A0);
float voltage = sensorValue * (5.0 / 1023.0);
Serial.println(voltage);
}
currently A0 pin is connected K02(the second column from left) and when I click a button from this column it shows me that:
http://prntscr.com/rd01sg
What are the units on the vertical scale? Volts?
The voltage of the calculator is 2v at max, so I don't think it'll fry the Arduino pin
The diagram shows 7.5V battery in the calculator though...
I suspect the keyboard multiplexing is too quick for analogRead(). Some analysis with a 'scope would
allow the actual waveform to be determined for certain - then perhaps a comparator could be
used to convert to digital signal (readable in < 1µs) rather than relying on the 110µs response
time of the analog pins.
