This guide is designed to get you started with MR603c as quickly
as possible. More information can be found in the
user manual -
MR603c receiver is 2.4GHz DSM2/DSMX receiver,
with 3A max brushed speed controller,
for use in larger scale model rail locomotives and road vehicles.
It is compatible with any Spektrum DSM2 or DSMX
transmitter including all of the Micron
model rail transmitters.
The voltage range is 5V to 20V.
If purchased with a transmitter, MR603c will be bound to the transmitter
and is ready for use;
otherwise, it requires binding to your transmitter.
Once bound, the transmitter should be switched on before the MR603c.
If the transmitter is not switched on, MR603c will automatically enter
bind mode 10 seconds after switch on; it may also be configured
to bind only manually using pads P5 and P6.
- Do not bend the receiver circuit board
- Connect the positive and negative input pads to a suitable battery or
power supply, via a on/off switch in the positive lead.
A resettable fuse must be placed in the battery positive lead
to protect the battery in the event of a wiring or component fault.
- Connect the 'M' pads to your vehicle motor, removing any connections
to track pickups. If your loco has suppression capacitors or chokes fitted,
leave them in place.
It is not usually necessary
to fit suppression components if your loco do not already have them.
Contact Micron if you do experience symptoms of motor noise interference.
- Connect any auxiliary circuits to the F and P pads; the P pads
are 3.3V pads when on and may
be used for powering auxiliary circuits with a maximum of 20mA per pad.
F pads are switches, open circuit when off and connected to negative
- Protect the receiver board before applying power for testing.
It must not be allowed to touch anything metal.
If MR603c was purchased with the heatshink cover supplied loose,
slide this over the circuit board.
- There is only one LED on the top side of the receiver board,
previous versions of MR603 had 2 LEDS.
- After switching on:
- the LED will slow flash while MR603c is searching for
its bound transmitter; if not already bound, approx 10 seconds
later the receiver will go into bind mode and the LED will
show a rapid flash; switch your transmitter on in bind mode and
the LED flashing will slow while the transmitter and receiver
are synchronising and then light continuously.
If the LED continues rapid flashing or the slower flashing does
not stop, try again with the transmitter slightly further away
from MR603 - for most transmitters, 50cm separation works well.
- When bound:
- the LED will be on to show receipt of good data
from the transmitter,
- the LED may flicker due to electrical (e.g
motor) noise, signal
fades caused by reflections,
interference from WiFi or Bluetooth signals,
or overloading from the transmitter (this will happen if the
transmitter is too close)
- the LED will show a slow repeated flash if the transmitter
signal is lost - e.g. if the vehicle has gone out of range for
more than 1 second or you have switched the transmitter off
- the LED will show a repeated double flash when MR603
is deselected (transmitter Selecta switch is moved)
- the CPU LED will show a repeated 5 flash if the low voltage
cutoff has triggered
- After testing, apply the heatshrink cover if not already fitted.
- Fix the receiver in place and, an extended aerial is fitted, route
this so that the last
30mm can 'see' the transmitter - e.g. by
routing through a hole in the vehicle body.
The aerial should not be cut short or made longer as this will
It is important to perform a range check after installation to ensure
you have full control of your loco/vehicle at all positions around
Double sided foam-cored sticky tape is ideal for mounting the receiver.
MR603c has solder pads for:
- power input (positive & negative battery)
- motor output
- 3.3V from the on-board regulator (max of 200mA)
- an additional battery negative connection (0V) - useful for wiring
LEDs to P pads
- L: used to monitor battery voltage when
a booster module is used, e.g. to raise a single LiPo cell to 12V.
- P1..P6: these are logic level outputs, 0V when off and 3.3V when on;
they can be configured for on/off switching or to output a servo signal;
P5 and P6 are at the opposite end of the board to the battery
and motor pads, a 4 pin JST-SH socket may optional be fitted for
P5, P6, 3.3V and 0V
- F1..F4: these are FET switches capable of up to 2A;
they are open circuit when off and
connected to battery negative when on; a load should be wired
between the F pad and battery positive, or the 3.3V pad for low
current loads; they are labelled A..D on the receiver board and
numbered 7..10 for programming
The simplest use of MR603c requires connection to a battery (via
an on/off switch and resettable fuse) and to your loco/vehicle motor.
LEDs on P pads should be connected between the pad and battery negative (0V)
with a series resistor appropriate to the required brightness.
Other connection diagrams (e.g. high current lights, sound card triggers) are
available on the Micron MR603c web page.
Take care when soldering wires to the battery, motor, P and
F pads as these are easily damaged by prolonged application of high
temperature. A temperature controlled iron used with thin flux cored
solder is best.
Also, if using stranded wire, ensure that none of the strands 'escape' to
short across adjacent pads.
The recommended technique is to fill the
pad hole with solder and then attach the wire to the top of the pad
- i.e. don't pass the wire through the pad hole.
- with transmitter off, switch MR603 on
- wait for the LED to flash fast
- switch your transmitter on in bind mode
- the LED flashing will slow for 2-5 seconds
and then light continuously
- MR603 is now bound to your transmitter