diff --git a/gex/__init__.py b/gex/__init__.py
index ea39353..71c7c89 100644
--- a/gex/__init__.py
+++ b/gex/__init__.py
@@ -20,6 +20,7 @@ from gex.units.ADC import ADC
 from gex.units.SIPO import SIPO
 from gex.units.FCAP import FCAP
 from gex.units.TOUCH import TOUCH
+from gex.units.PWMDim import PWMDim
 
 
 # General, low level
diff --git a/gex/units/PWMDim.py b/gex/units/PWMDim.py
new file mode 100644
index 0000000..728c705
--- /dev/null
+++ b/gex/units/PWMDim.py
@@ -0,0 +1,43 @@
+import gex
+
+CMD_SET_FREQUENCY = 0
+CMD_SET_DUTY = 1
+CMD_STOP = 2
+CMD_START = 3
+
+class PWMDim(gex.Unit):
+    """
+    Simple 4-channel PWM output with a common frequency
+    """
+
+    def _type(self):
+        return 'PWMDIM'
+
+    def set_frequency(self, hertz:int, confirm=True):
+        """ Set freq """
+        pb = gex.PayloadBuilder()
+        pb.u32(hertz)
+        self._send(CMD_SET_FREQUENCY, pb.close(), confirm=confirm)
+
+    def set_duty(self, duty_dict, confirm=True):
+        """ Set duty (dict - number1234 -> duty 0-1000) """
+        pb = gex.PayloadBuilder()
+
+        for (k,v) in enumerate(duty_dict):
+            pb.u8(k-1)
+            pb.u16(v)
+
+        self._send(CMD_SET_DUTY, pb.close(), confirm=confirm)
+
+    def set_duty_single(self, ch1234, duty1000, confirm=True):
+        """ Set duty of a single channel """
+        pb = gex.PayloadBuilder()
+        pb.u8(ch1234-1)
+        pb.u16(duty1000)
+        self._send(CMD_SET_DUTY, pb.close(), confirm=confirm)
+
+    def stop(self, confirm=True):
+        self._send(CMD_STOP, confirm=confirm)
+
+    def start(self, confirm=True):
+        self._send(CMD_START, confirm=confirm)
diff --git a/owtest.py b/owtest.py
new file mode 100644
index 0000000..9bd503c
--- /dev/null
+++ b/owtest.py
@@ -0,0 +1,66 @@
+#!/bin/env python3
+import time
+
+import gex
+
+with gex.Client(gex.TrxRawUSB()) as client:
+    ow = gex.OneWire(client, 'ow')
+    # print("Presence: ", ow.test_presence())
+    print("Devices:", ow.search())
+
+    def meas(addr):
+        ow.write([0x44], addr=addr)
+        ow.wait_ready()
+        data = ow.query([0xBE], 9, addr=addr)
+        pp = gex.PayloadParser(data)
+        return pp.i16() * 0.0625
+
+    while True:
+        a = meas(6558392391241695016)
+        b = meas(1802309978572980008)
+        print("in: %.2f °C, out: %f °C" % (a, b))
+
+
+
+    # # search the bus for alarm
+    # if False:
+    #     ow = gex.OneWire(client, 'ow')
+    #     print("Presence: ", ow.test_presence())
+    #     print("Devices w alarm:", ow.search(alarm=True))
+    #
+    # # simple 1w check
+    # if False:
+    #     ow = gex.OneWire(client, 'ow')
+    #     print("Presence: ", ow.test_presence())
+    #     print("ROM: 0x%016x" % ow.read_address())
+    #     print("Scratch:", ow.query([0xBE], rcount=9, addr=0x7100080104c77610, as_array=True))
+    #
+    # # testing ds1820 temp meas without polling
+    # if False:
+    #     ow = gex.OneWire(client, 'ow')
+    #     print("Presence: ", ow.test_presence())
+    #     print("Starting measure...")
+    #     ow.write([0x44])
+    #     time.sleep(1)
+    #     print("Scratch:", ow.query([0xBE], 9))
+    #
+    # # testing ds1820 temp meas with polling
+    # if False:
+    #     ow = gex.OneWire(client, 'ow')
+    #     print("Presence: ", ow.test_presence())
+    #     print("Starting measure...")
+    #     ow.write([0x44])
+    #     ow.wait_ready()
+    #     data = ow.query([0xBE], 9)
+    #
+    #     pp = gex.PayloadParser(data)
+    #
+    #     temp = pp.i16()/2.0
+    #     th = pp.i8()
+    #     tl = pp.i8()
+    #     reserved = pp.i16()
+    #     remain = float(pp.u8())
+    #     perc = float(pp.u8())
+    #
+    #     realtemp = temp - 0.25+(perc-remain)/perc
+    #     print("Temperature = %f °C (th %d, tl %d)" % (realtemp, th, tl))
diff --git a/pwmbeep.py b/pwmbeep.py
new file mode 100644
index 0000000..1206a6b
--- /dev/null
+++ b/pwmbeep.py
@@ -0,0 +1,45 @@
+import time
+
+import gex
+
+C3  = 130.81; Cx3 = 138.59; D3  = 146.83; Dx3 = 155.56; E3  = 164.81; F3  = 174.61
+Fx3 = 185.00; G3  = 196.00; Gx3 = 207.65; A3  = 220.00; Ax3 = 233.08; B3  = 246.94
+C4  = 261.63; Cx4 = 277.18; D4  = 293.66; Dx4 = 311.13; E4  = 329.63; F4  = 349.23
+Fx4 = 369.99; G4  = 392.00; Gx4 = 415.30; A4  = 440.00; Ax4 = 466.16; B4  = 493.88
+C5  = 523.25; Cx5 = 554.37; D5  = 587.33; Dx5 = 622.25; E5  = 659.25; F5  = 698.46
+Fx5 = 739.99; G5  = 783.99; Gx5 = 830.61; A5  = 880.00; Ax5 = 932.33; B5  = 987.77
+
+with gex.Client(gex.TrxRawUSB()) as client:
+    pwm = gex.PWMDim(client, 'dim')
+
+    # O   O/ #/ #~ #=
+    # 16, 8, 4, 2, 1
+    notes = [
+        (G3, 2),
+        (G4, 2), (E4, 6), (G4, 2), (E4, 2), (A4, 6), (0, 2), (B4, 2),
+        (G4, 2), (E4, 6), (A4, 2), (G4, 2), (D4, 6), (0, 2), (G3, 2),
+
+        (G4, 2), (E4, 6), (D4, 2), (C4, 2), (C5, 6), (0, 2), (A4, 2),
+        (G4, 2), (E4, 4), (0, 2), (D4, 2), (A3, 2), (C4, 6), (0, 2), (G3, 2),
+
+        #rep
+        (G4, 2), (E4, 6), (G4, 2), (E4, 2), (A4, 6), (0, 2), (B4, 2),
+        (G4, 2), (E4, 6), (A4, 2), (G4, 2), (D4, 6), (0, 2), (G3, 2),
+
+        (G4, 2), (E4, 6), (D4, 2), (C4, 2), (C5, 6), (0, 2), (A4, 2),
+
+        (G4, 2), (E4, 6), (D4, 2), (A3, 2), (C4, 6), (0, 2), #(C4, 2),
+    ]
+
+    for p in notes:
+        pwm.stop()
+        time.sleep(0.01)
+        f = round(p[0])
+        print(f)
+        if f > 0:
+            pwm.set_frequency(f)
+            pwm.start()
+        time.sleep(0.1*p[1])
+
+    pwm.stop()
+
diff --git a/pwmbeep2.py b/pwmbeep2.py
new file mode 100644
index 0000000..fbb387a
--- /dev/null
+++ b/pwmbeep2.py
@@ -0,0 +1,15 @@
+import time
+
+import gex
+
+with gex.Client(gex.TrxRawUSB()) as client:
+    pwm = gex.PWMDim(client, 'dim')
+
+    pwm.start()
+    pwm.set_duty_single(1, 500)
+    for i in range(2000, 200, -15):
+        pwm.set_frequency(i)
+        time.sleep(0.05)
+
+    pwm.stop()
+