I'm not sure if this is the best category to ask this in, or if this was the best way to phrase the question, but I'm working on a project and I could use input from people who are a bit more experienced than myself. I am very new to this, so I appreciate any help I can get!
Note: I'm using pyserial to communicate serially, tkinter to create the GUI, and of course, Arduino to contol my hardware.
The goal: Basically, the project needs to open an excel file using a GUI - the excel file holds data concerning relative pressures/forces that two large stepper motors (attached to screws to extend and contract) should apply to an object. The file has 3 columns: the time (each entry is separated by a small fraction of a second), the force for motor 1 at that time, and the force for motor 2 at that time.
I've been having a difficult time getting this to work. The machine has to run for hours at a time, and the time difference between each entry is very small, such that every time I've tried to send it continuously, I get no response from the Arduino.
Options:
- Would the best option be to try and send it and store it all at once? I know Arduino has very little space, but there is a way to increase the storage with SD cards and other devices - correct?
- Or would it be best to try and figure out how to send it very quickly and continuously? That seems to be the method that simplifies my code the most, but the Arduino is so unresponsive when that happens! Am I doing something wrong there?
- Another option I was considering would be to try and have the Arduino read directly from the excel file - which I have no idea if it is feasible or not.
I am very open to other ideas if anyone has any!
If it helps I also attached the code I have so far which hasn't been working. I'm trying the continuous stream method here and it's been rough.
Here is my relevant python code to send the data:
def sendValues():
'''
send a value over if the motor is on, then wait however long
'''
global loadDiffValues
global shearDiffValues
global timeDiffValues
global axialStatus
global shearStatus
while True:
while axialStatus == "On" or shearStatus == "On":
ser.reset_input_buffer()
ser.reset_output_buffer()
if axialStatus == "On":
sendA = "A"+str(loadDiffValues[0])
print('sent')
else:
sendA = 'a'
ser.write(sendA.encode())
ser.reset_input_buffer()
ser.reset_output_buffer()
if shearStatus == "On":
sendS = "S"+str(shearDiffValues[0])
else:
sendS = 's'
ser.write(sendS.encode())
ser.reset_input_buffer()
ser.reset_output_buffer()
timeDiffValues[0] = float(timeDiffValues[0])
sendT = "T"+str(timeDiffValues[0])
ser.write(sendT.encode())
ser.reset_input_buffer()
ser.reset_output_buffer()
time.sleep(float(timeDiffValues[0])) //this is around 0.01 or so
loadDiffValues = loadDiffValues[1:]
shearDiffValues = shearDiffValues[1:]
timeDiffValues = timeDiffValues[1:]
and here is the corresponding Arduino code:
boolean axialStatus = 0; //start with both motors off
boolean shearStatus = 0;
double pulse_delay(double posChange, double transitionTime);
float time_value;
float axial_value;
float shear_value;
void setup() {
pinMode(PulseAxialV, OUTPUT); pinMode(DirAxialV, OUTPUT); pinMode(PulseShearV, OUTPUT); pinMode(DirShearV, OUTPUT);
Serial.begin(9600);
}
void loop() {
unsigned long currentTime = millis();
if (Serial.available()>0){
String value = Serial.readString();
if (value.substring(0,1)=="A"){
previousTimeAxial = millis();
axialStatus = 1;
float axial_value = value.substring(1).toFloat();
if (axial_value < 0){
digitalWrite(DirAxialV, LOW);
}
else if (axial_value > 0){
digitalWrite(DirAxialV, HIGH);
}
}
else if (value.substring(0,1)=="S"){
previousTimeShear = millis();
shearStatus = 1;
float shear_value = value.substring(1).toFloat();
if (shear_value < 0){
digitalWrite(DirShearV, LOW);
}
else if (shear_value > 0){
digitalWrite(DirShearV, HIGH);
}
}
else if (value.substring(0,1)=="T"){
float time_value = value.substring(1).toFloat();
}
else if (value.substring(0,1)=="a"){
axialStatus = 0;
}
else if (value.substring(0,1)=='s'){
shearStatus = 0;
}
else if (value.substring(0,1)=='l'){
axialStatus = 0;
shearStatus = 0;
}
}
if (axialStatus == 1){
if (currentTime - previousTimeAxial < pulse_delay(axial_value, time_value)){
digitalWrite(PulseAxialV, HIGH);
}
if (currentTime - previousTimeAxial < 2*pulse_delay(axial_value, time_value)){
digitalWrite(PulseAxialV, LOW);
}
else {
previousTimeAxial = currentTime;
}
}
else {
digitalWrite(PulseAxialV, LOW);
}
if (shearStatus == 1){
if (currentTime - previousTimeShear < pulse_delay(shear_value, time_value)){
digitalWrite(PulseShearV, HIGH);
}
else if (currentTime - previousTimeShear < 2*pulse_delay(shear_value, time_value)){
digitalWrite(PulseShearV, LOW);
}
else {
previousTimeShear = currentTime;
}
}
else {
digitalWrite(PulseShearV, LOW);
}
}
//the rest isn't too important for my problem, ignore it
float coeff = 0.45714;
double pulse_delay(double posChange, double transitionTime){
if (posChange == 0){
return 0.0;
}
else{
double pd = coeff*transitionTime*1250/posChange;
return pd;
}
}
