8.3.1 Meter operation
Figure 64. Meter operation
• Press SW1 to cycle through charging states. Each state is indicated by a single digit (current charging state). The LEDs
also illuminate according to the current charging state. Connector J25 Pin 20 can be used to measure the output JAE
1772 PWM on J25-P22.
• Press SW2 to simulate the error and unknown error states. This changes the current charging state to 5 or 6, turns on the
error-state indicator in the LDC, and changes the color of the charging-state LEDs.
STATE
D (4)
STATE
B (2)
STATE
C (3)
STATE
A (1)
STATE
E (5)
STATE
F (6)
EV not
connected
EV
Connected
And ready
EV
Charge
Vent cycle
EV
Charge
Transition on
any SW1 press
Transition on
any SW2 press
SW1 press
SW2 press
Reset
PWM f. = 1 kHz
PWM f. = 1 kHz
PWM f. = 1 kHz
PWM f. = DC
Figure 65. Basic charging state machine
• Adjusting the rotary potentiometer changes the simulated instantaneous current drawn by the vehicle. This current is then
used by the metrology library to calculate the RMS current and associated power measurements being reported over the
simulated electrical mains cycle. The instantaneous current displayed on the TWR3x LCD screen will not always match
the calculated RMS current displayed on the i.MX RT106x GUI screen, especially during the adjustment of the rotary VR.
NXP Semiconductors
System powerup and operation
NXP EasyEVSE EV Charging Station Development Platform User Guide, Rev. 0, 18 March 2022
User Guide
47 / 64
