1
2
3
4
5
6
A
A
Makita(+)
VCC5V
C2
C1
21
20
19
18
17
0
1
2
3
4-SDA
Hardware TWI
5-SCL
PWM-5
Software TWI
SDA
12
5
11
6
10
7
9
4
PWM-3
2
TX-1
RX-0
IA
OA
Schematic Symbol Drawn By Opendous Inc. www.opendous.org
IB
OB
IC
OC
OD
ID
Vsel-Ve
RCout-NC
Pink
U2
14
2
3
1
13
12
11
10
Makita(+)
Makita(-)
9
SCK
SI
CS
Makita(+)
IC1
MCP4161 10K
8
GNDiso
15
VDD
4
GND
16
VSS
3
13
GND
7
PWM-6
SCL
GND
GNDiso
PA0
PW0
PB0
5
6
7
Makita(signal)
J1
1
2
3
White
At least one of the Makita speed controllers
I have, had a Telefunken U211B3 chip inside it.
B
Makita Speed Controller
Black
8
Makita(-)
7
6
As the Makita is a double insulated tool,
the voltage on the potentiometers pins
can be very high related to ground level.
You should make sure those pins cannot
make contact with anyting that is grounded
like yourself or your computers USB which
you might use to power your Arduino.
5
4
3
2
1
9V double insulated power supply (not connected to earth),
which is used to regulate voltage for the Makita controller.
LM317L
2
VO
D1
Makita(+)
D
C3
1uF
C
240
R1
ADuM1401 isolator is used to disconnect
the digital potentiometer your Arduino.
+9V
U3
VI
3
ADJ
22
VIN
8
14
8
100nF
Viso
GND
C4
RTRIM 2K
GND
GND
15
SPI is used only for
writing, not reading
ADuM1401
VDD
1
23
GND
PWM-9
16
2
R2
24
5V
DIGITAL
25
3V3
SS-PWM-10
ARDUINO_PINOUT
26
SCK-13
MOSI-PWM-11
nRESET
POWER
27
VCC5V
GND
MISO-12
ANALOG IN
28
B
USB
DC_IN
U1
AREF
1
4
100nF
0.1uF
Makita(-)
Voltage needs to be first measured
from the Makita's controller with
the potentiometers middle wire
connected to Makita(-). I had one
controller with 3.6V and another with
5.2V. Use the trimmer to adjust the
LM317's voltage output to this
voltage. The trimmer can be used
later to widen the RPM range of
the router. I set mine to 8,000-36,000RPM.
C
GND2
GND2 is not connected to the Arduino's GND.
Sheet: /
File: Makita_speed_controller_MCP4161.sch
D
Title:
D
Makita RT0700 Speed Controller with MCP4161 Digital Potentiometer
Size: A4
Date: 13.10.2017
KiCad E.D.A. kicad 4.0.7
1
2
3
4
Rev: 1.3
Id: 1/1
5
6