*** Please read this notice about shipping charges and VAT if your delivery address is outside the U.K. ***
Micron MR601a 2.4GHz DSM2/DSMX Receiver (from v1.7)
PDF
This document is for MR601 from version 1.7, other versions can be found via the table on page http://micronrc.co.uk/mr6xx_version.
The MR601a receiver is designed for use in smaller scale model rail locomotives and road vehicles. It provides a 1.2A reversible ESC for brushed motors and 5 auxiliary outputs for lighting, sound triggers, couplers, etc. It operates on 2.4GHz and is compatible with any Spektrum DSM2 or DSMX transmitter including all of the Micron model rail transmitters. The voltage range is 2.7V to 13V.
MR601 requires binding with your transmitter before use. If purchased with a transmitter, it will be already bound to that transmitter. Once bound, the transmitter should be switched on before the MR601. If the transmitter is not switched on,MR601 will automatically enter bind mode 10 seconds after switch on.
The MR601 free-air range, when used with a Micron low-power transmitter, is 40m-50m and approximately 200m when used with a full-power (100mW) transmitter. This range will be reduced indoors due to absorption by furniture / fittings and reflections from metal surfaces. Range is also reduced if the receiver aerial is enclosed within a metal body. In this case, the extended aerial should be used and this is routed so that the active tip (last 30mm) is outside the vehicle body - e.g. though a small hole into the cab space. The aerial should not be cut short or made longer as this will affect operation of the receiver. It is important to perform a range check after installation to ensure you have full control of your loco/vehicle at all positions around the layout.
Features (top)
Usage (top)
Connections (top)
MR601 has solder pads for:
LEDs on P pads should be connected between the pad and battery negative (0V) with a series resistor appropriate to the required brightness. There is a series 120 ohm resistor on the PCB to protect the microprocessor IO port. LEDs or incandescent lamps on F pads should be connected between the pad and battery positive or the 3.3V pad and with a series resistor appropriate to the voltage and required brightness.
Sound card inputs are usually 5V open circuit and are triggered when connected to negative. They should be connected to an F pad. A P pad may be used if you have more trigger inputs than F pads, or a P to F converter is available from Micron - this is a small board containing 1, 2, 3 or 6 FET switches. If the P output is used directly for sound card trigger, a 4k7 ohms resistor must be connected in series to avoid stressing the MR601 microprocessor; the P output should be configured for 3.3V idle and 0V when the Tx control is actioned.
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.
Low Voltage Cutoff (top)
MR601 can be powered from a battery of 5V up to 20V. The speed controller will stop the motor if the battery drops below 5V but the other receiver functions will continue to operate down to 4V.
The default receiver setting is for the Low Voltage Cutoff (LVC) threshold to be determined from the voltage measured at switch on. This is auto mode which is essential when the receiver is powered using a Lithium battery (LiPo or LiIon) as these must not be discharged below 3V per cell. The algorithm used for this calculation means that a 9V Alkaline or NIMH battery can often be interpreted as an almost discharged 3S LiPo. The solution is to either disable LVC, or set it to the correct value for your battery. Switching between auto and disabled can be done using a power-on configuration change and the LVC threshold can be set to a specific value by programming the receiver.
LED Error Codes (top)
If the receiver firmware detects a fault, all functions are disabled and the LED will display a repeated pattern of 0.5 seconds rapid flashing followed by a N-flash where N is the error code
Binding (top)
MR601 must be bound to a transmitter before use. Once bound, MR601 remembers the transmitter identity and searches for this when it is switched on.
To bind a receiver, it is switched on with no transmitter active (for normal operation, the transmitter should be switched on before the receiver).
The default configuration is for autobind where the receiver automatically goes into bind mode approx 10 seconds after switching on with no pre-bound transmitter active. Manual binding may be configured by programming - this could be useful, for example, if the loco is to be used by children who could forget to switch the loco/receiver on first.
Bind mode is indicated by a rapid flashing of the receiver LED and the following steps should be followed to bind with your transmitter:
Loco Selection - Selecta (top)
Many Micron model rail transmitters have a 12 way switch to allow control of up to 12 locos - Deltang originated this feature and called it 'Selecta'. Using the switch, locos are brought under control one at a time. When not selected, receiver outputs hold their current setting (e.g. a loco which is moving when deselected keeps moving) and the LED shows a 2-flash pattern. The default 'keep going' behaviour can be changed to stop when deselected by programming the receiver.
The Micron implementation of Loco Selection / Selecta is fully compatible with the Deltang Selecta feature and uses R/C channel 2 by default. When Selecta is enabled, the controlling R/C channel (e.g. 2) may still be mapped to a receiver output but, of course, this will not change as the transmitter switch is rotated.
The receiver has a 800ms delay before enabling when the transmitter Selecta value is changed. This is to avoid obeying the transmitter while the Selecta switch is being moved - e.g. a receiver on Selecta #4 should not change any outputs while the transmitter Selecta switch is moved from #3 to #5.
Selecta may be enabled by default (see the receiver configuration information) and may be enabled or disabled by using a power-on configuration change (see Power-On Configuration Changes) or by programming.
If Selecta is enabled, the transmitter's Selecta switch value will be saved when the transmitter and receiver are bound. A new Selecta value (i.e. switch position) can be stored either by rebinding or by using the power-on changes to disable and then re-enable Selecta.
Note: when the Selecta switch is changed to control a different loco, the newly selected loco responds to the transmitter control settings. The current range of Selecta enabled transmitters have no model memory so cannot have different throttle settings, etc. for each loco. Thus, although Selecta may be used to manage many moving locos, this must be used with care and is not recommended. Micron intends to introduce a transmitter with model memory but the release date is not known.
Directional Lighting (top)
Most configurations have pads P1/P2 or F1/F2 setup to drive front and rear lights; P1/F1 powers a forward light and P2/F2 a backward facing light. The directional lighting pins can be changed by programming the receiver.
P1/P2 should be used for LEDs and F1/F2 for high voltage (e.g. incandescent) lights.
MR601 has an on-board 3.3V regulator and 120 ohm resistors in series with the P1 to P3 so limits the LED current to approximately 20mAh. Most high brightness LEDs require much less than this so an additional resistor should be used - e.g. 100 - 1k ohms. The LED should be connected between P1/P2 and battery negative (0V).
LEDs or high voltage lights should be connected between F1/F2 and either the 3.3V pad or battery positive (with and appropriate value series resistor).
The directional LEDs follow the throttle channel if configured for centre-off, changing when the throttle passes though the off position. If the throttle is configured for low-off, the LEDs change only when the throttle is at zero - i.e. the direction control can be altered at any time but the LEDs (and motor direction) changes only when the throttle is closed.
The throttle mode (centre or low off) can be changed by programming or by using one of the power-on configuration changes
Cruise Control / Failsafe (top)
If the receiver loses the signal from the transmitter, for example when going through a tunnel or behind a garden building or some dense bushes, MR601 outputs hold their current setting until the transmitter signal is reacquired. The motor also continues running when a Selecta-enabled receiver (see Selecta) is de-selected.
This is a form of 'cruise control' which allows you to switch off the transmitter if, for example, you are running the loco round a continuous circuit.
Cruise control can be disabled using a Power-On Change or by programming. If cruise control is disabled, the receiver will 'fail safe' and the motor will be stopped when signal is lost.
Emergency Stop (top)
Any of the transmitter controls can be used as an 'Emergency Stop' function to rapidly bring the loco/vehicle to a stop. Emergency Stop is not enabled by default and must be configured by programming the receiver.
To enable Emergency Stop, you need to choose:
Power-On Configuration Changes (top)
A few configuration changes can be made without programming. A simple link across 2 of the auxiliary P pads is used to action the change. This is easily achieved using some needle nose tweezers and, if they are sharp pointed, can penetrate the receiver's heatshink cover. A change is made by:
The changes all toggle (or cycle) the parameter value each time the process is performed. The LED flash indicates the new state of the configuration parameter. The receiver has to be switched off after the change as it will be stuck in the rapid flash mode to indicate that the change has been made. If you switch off before removing the P connection, the configuration is not changed.
This is a summary of the configuration changes that can be made using a jumper across 2 of the P pads.
Each flash count is repeated twice and then increments to the next, cycling back to 1 when the max is reached.
Note:
Receiver Programming (top)
The behaviour for each MR601 pad (ESC, F or P) can be changed using a bound transmitter. MR601 must first be put into programming mode and then the direction toggle switch, or elevator on a stick type transmitter, is used to enter a program sequence one digit at a time. The LED (and LED2 if enabled) flashes to indicate the value of the current step in the programming sequence. For example, if the current value is 4, the LED flashes 4 times, pauses and repeats - this is called a 4-flash.
The programming table is large and presented in a separate document (see micronrc.co.uk/mr6xx_progtable) which lists all of the functions that may be changed by programming. The table is split into 5 blocks of related functions each with the same value in the first column.
The table columns contain the program values which must be entered to change a particular function. For example, to change the throttle behaviour from centre-off (forward and reverse on one Tx control) to low-off (separate throttle/regulator and direction/reverser controls) the program sequence 1, 1, 2, 1, 3 is entered. Each digit of this program sequence is taken from the columns, left to right:
One function can be changed at a time. The general method is:
There are 3 methods of getting the MR601 into programming mode:
When programming mode has been successfully entered, the receiver LED will show a 1-flash - this is the 1 from the first column of the programming table. If you do not get the 1-flash, repeat the procedure to enter programming mode. It usually takes a couple of attempts to get the SOS method correct if you have never done it before.
One programming change requires up to five choices to be made. These are called 'levels' and each has several options. They are documented in the programming table. Completion of a programming change exits programming mode and requires the receiver to be placed into programming mode again for the next change.
It is a good idea to write the programming sequence on a piece of scrap paper and cross off each digit as it is entered so that you don't lose track of where you are in the sequence. You always start at the top of the first column and 1-flash is displayed on entering programming mode.
Most Micron transmitters have a toggle switch on R/C channel 3 which is marked A/B, or forward/reverse for a low-off transmitter:
The receiver LED will flash rapidly while R/C channel 3 is high or low and then return to a slower repeated flash when the control is back to the middle.
After accepting the flash count for a level, the LED displays a flash count for the current value of the next level. This could be higher than 1-flash if the function is set in the receiver configuration or has been previously programmed. For example:
When the last level for a sequence has been accepted, the LED will light continously and the receiver is back in normal operating mode. The maximum number of levels is 5, but not all sequences use all 5; if level 5 in the table is blank, the LED will light continously after level 4 is accepted.
Programming changes are accepted only when the LED lights solid at the end of the sequence. If a mistake is made mid way through a sequence, switch the receiver off to abort.
These examples assume MR601 is in as-received configuration and a Micron transmitter with toggle switch on R/C channel 3. Tx24v2 transmitters have a variable control on R/C channel 3 - the Reverser; the equivalent actions are:
The programming table for MR601 can be found at micronrc.co.uk/mr6xx_progtable.
Servo Throw Adjustment (top)
Servo throws (low and high end points) can be configured using a bound transmitter, the servo centre position will always be at the mid-point of the low and high travel. To adjust a servo, the servo output is selected first and then the travel adjusted using either the throttle control or direction toggle if the throttle servo is being adjusted.
The steps below assume a Micron transmitter is being used. If the transmitter is an aeroplane type stick transmitter then the elevator stick corresponds to the direction toggle.
Only one servo output can be changed at a time. Go through the above steps to adjust a different servo output pin.
This configuration table is for firmware version 1.7. For other versions, refer to mr6xx_version.
The pre-loaded configurations are shown below. Unless otherwise specified when the receiver was ordered, config 1 is enabled by default. The other loaded configurations can be selected using a power-on configuration change or by programming.
Other configurations are available to special order or you can configure yourself by programming.