Run two functions at once - arduino

Question

This program is a simple program designed to plot at the same time both your & Uc on the serial monitor. Arduino runs through the first for loop & plot the F1 function and after that does the same with F2. My objective is to plot them both at the same time.
My idea is to actually take a small fraction of time, let's say 10 ms, to plot F1 & the next 10 ms to plot F2, but I don't know how to write this down. I think the millis function is the solution, but I'm not quite sure how to implement it.
const short int R = 5000;
const float C = 0.0005;
const float TE = 0.1;
const float Tau = R*C;
const short int E = 5;
float t, Tinit,Tfin;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
}
void loop() {
//F1
for ( t = 0; t <= 20; t = t+TE)
{
float Ur = E*exp(-t/Tau);
Serial.println (Ur);
}
//F2
for ( t = 0; t <= 20; t = t+TE)
{
float Uc = E*(1-exp(-t/Tau));
Serial.println (Uc);
}
}

Answer 1

Thread can be used to solve your problem . It has a huge documentation , it is widely used library for Arduino(unofficial).
Give it a try.
It will be easy for you, if you see these :
Example - 1 (thread instance example)
Example - 2 (callback example)
Example - 3 (It is still buggy , but I think it will help)
If you want to do it without libraries , then you need to create two functions , without those loops . Like
void f1()
{
float Ur = E*exp(-t/Tau);
Serial.println (Ur);
}
void f2()
{
float Uc = E*(1-exp(-t/Tau));
Serial.println (Uc);
}
Now inside "void loop()" you can implement the basic logic of threading , which will be pretty rough , but fulfill your requirements. Like :
void loop() {
unsigned long now = millis();
static unsigned long last_finger_update;
if (now - last_finger_update >= FINGER_UPDATE_PERIOD) {
last_finger_update = now;
f1();
}
static unsigned long last_wrist_update;
if (now - last_wrist_update >= WRIST_UPDATE_PERIOD) {
last_wrist_update = now;
f2();
}
}
You have to declare two variables
const unsigned long FINGER_UPDATE_PERIOD = 1000;
const unsigned long WRIST_UPDATE_PERIOD = 1000;
All time units are in milliseconds. This strategy is collected from internet.

Answer 2

The most deterministic way of handling this is simply:
for (t = 0; t <= 20; t = t + TE) {
float Ur = E*exp(-t/Tau);
float Uc = E*(1-exp(-t/Tau));
Serial.println (Ur);
Serial.println (Uc);
}
More generally, you can implement a primitive resource scheduler:
while (true) {
task_one();
task_two();
}

Answer 3

You can do that Easily if you run RTOS in MCU as you know other solutions will also be sequential...
I've been using TridentTD_EasyFreeRTOS library it has easy way of having multiple tasks and controlling them in different sketch files..