Table of Contents
IpidRun()
IpidRun() calculates the PID output from the current value and setpoint.
float IpidRun(uint8_t id, float pv, float sv)
Commands
| Command | Arguments | Return Value | Operation |
|---|---|---|---|
IpidRun(id, pv, sv) | uint8_t id — PID loop number. Supports 0 ~ 255float pv — Current value. Present Valuefloat sv — Setpoint. Set Value | float | Calculates the PID output from the current value and setpoint. |
Example
void setup() { IpidSet(2, 4.0, 0.2, 0.0, 100, 0, 255); // Set PID coefficients, calculation interval and output range. IpidReverse(2, true); // Select direct or reverse PID action. } void loop() { float pv = ntcRead(4) / 10.0; // Return the NTC 3950 10kΩ sensor temperature as an integer in 0.1°C units. float sv = 25.0; int output = (int)IpidRun(2, pv, sv); // Calculate the PID output from the current value and setpoint. analogWrite(11, output); }
Precautions
- PID output can directly affect field equipment. Begin testing with a low output range and small gains.
IpidRun()retains the previous output until thesampleMsinterval has elapsed. It may be called repeatedly inloop().- The integral term is automatically constrained by the output limits to reduce windup. Use
IpidItermLimit()if additional limits are needed. - The derivative term is calculated from the PV change to reduce abrupt jumps caused by setpoint changes.
IpidReset()resets the integral term, previous PV and previous output value.- Use the same
idfor only one control loop.