diff --git a/obi_power.py b/obi_power.py
new file mode 100644
index 0000000..ada7bc0
--- /dev/null
+++ b/obi_power.py
@@ -0,0 +1,101 @@
+import utime
+from machine import Pin, Timer
+import config as cfg
+import port_io
+
+cf1_count = 0
+cf_count = 0
+cf1_frequency = 0
+cf_frequency = 0
+sel = 0
+
+'''
+Upstream/Downstream values of voltage devider:
+
+Ru/Rd = 2400/1
+
+Series resistor for current measurement:
+
+Rs = 0.001
+
+From the data sheet:
+
+Vref = 1.218
+
+Power:
+FCF = 1721506  * V(V)*V(I) / Vref^2
+
+Voltage:
+FCFU = 15397 *  V(V) / Vref
+
+Current:
+FCFI = 94638 *  V(I) / Vref
+'''
+
+def calc_power(cf, cf1, sel):
+    if sel:
+        v = cf1 * 0.18677
+        i = 0.0
+    else:
+        v = 0.0
+        i = cf1 * 0.01287
+    p = cf * 2.069
+    return v, i, p
+
+def callback_cf1(p):
+    global cf1_count
+    cf1_count += 1
+
+def callback_cf(p):
+    global cf_count
+    cf_count += 1
+
+def total(t):
+    global cf_count
+    global cf1_count
+    global sel
+    cf1_frequency = cf1_count
+    cf_frequency = cf_count
+    cf1_count = 0
+    cf_count = 0
+    print("--> ",sel, calc_power(cf_frequency, cf1_frequency, sel))
+
+port_io.setup_ports()
+
+port_io.set_output(cfg.RELAY, 1)
+port_io.set_output(cfg.LED_R, 1)
+
+cf1_pin = cfg.inputs[cfg.CF1]['obj']
+cf_pin = cfg.inputs[cfg.CF]['obj']
+
+print(cf1_pin, cf_pin)
+
+cf1_pin.irq(trigger=Pin.IRQ_FALLING, handler=callback_cf1)
+cf_pin.irq(trigger=Pin.IRQ_FALLING, handler=callback_cf)
+
+
+# IRQ method
+'''
+timer = Timer(-1)
+timer.init(period=1000, mode=Timer.PERIODIC, callback=total)
+
+while (1):
+    port_io.set_output(cfg.SEL, sel)
+    port_io.set_output(cfg.LED_G, sel)
+    utime.sleep(5)
+    sel = 1 - sel # toggle
+'''
+
+# polling method
+while(1):
+    port_io.set_output(cfg.SEL, sel)
+    port_io.set_output(cfg.LED_G, sel)
+
+    cf1_count = 0
+    cf_count = 0
+    utime.sleep(1)
+    cf1_frequency = cf1_count
+    cf_frequency = cf_count
+    print("--> ",sel, calc_power(cf_frequency, cf1_frequency, sel))
+
+    sel = 1 - sel # toggle