Workflow for running CJ125

How CJ125 runs

Running phases

Phase 1, startup

startup the MCU
init GPIO, registers, PWM, ADC, DAC, SPI, CAN...

Phase 2, calibration

read diag register of CJ125
put CJ125 into calibration mode
read Ua (ADC value for λ=1), store them (Ua_calibration)
read Ur (ADC value for optimal heater power and heater temperature), store them (Ur_calibration)

Phase 3, condensation

put CJ125 into measurement mode, amplification 17 (VL=1, λ = 0.75...∞)
drive heater with 1.5V for 5 seconds

Phase 4, heat up

drive heater with 8.5V to 13V (not UBat!), with 0.4V/s

Phase 5, running

PID heater control (read Ur)
read Ua
calculate Ip (pump current)

Ip calculation

Ip(A) = (Ua - Ua_calibration) / (amplification * Rshunt)

Ua: actual Ua value
Ua_calibration: stored value from calibration step (approx. 1.5V)
amplification: amplification factor, 8 (rich applications, λ < 1) or 17 (lean applications, λ > 1)
Rshunt: resistance of shunt resistor between IA and IP for pump current sensing, always 61.9 Ohm for LSU4.2 and LSU4.9