Diagram

1 2
J2
1 2
J3
1
2
4
3
5
J14
PD0
PD1
ADC6
ADC7
PC5
1
2
4
3
5
J15
PB3
PC6
VCC
VBAT
VBOOST
D4b
LED_T1
1k
R25b
PD7
1
2
4
3
5
J16
PD0
PD1
ADC6
ADC7
PC5
1
2
J17
VBOOST
1
2
J19
VBAT
1
2
J18
PD0
PD1
10 uF
C29
C1206
VBOOST VBAT
1.0 uF
C30
C0603
22 uF
C31
C1206
VCC
D4a
GREEN
1k
R25a
L2
10 uH
1.0 uF
C19
0.1 uF
C13
0.1 uF
C14
0.1 uF
C18
VCC AVCC
0.1uF
C15
0.1 uF
C16
0.1 uF
C17
VIN
ON
GND
NR
VOUT
U2 PQ1LA503MSPQ
VBOOST
0.1 uF
C20
1.0 uF
C12
1 2
3 4
5 6
7 8
J8
1 2
3 4
5 6
7 8
J9
1 2
3 4
5 6
7 8
J10
1 2
3 4
5 6
7 8
J11
1 2
3 4
5 6
7 8
J12
1 2
3 4
5 6
7 8
J13
47k
R6
Q3
47k
R1
10k
R2
10k
R5
100k
R7
SW1
pushbutton
100k
R3
1.0 uF
C3
D1a
BLUE
VBAT
1.0 uF
C1
1k
R4a
Q1 PFETMICRO2x2 Q2 PFETMICRO2x2
B1
2xAAA
B2
2xAAA
100 uF
C2b
D1b
T1
1
2
J7
charge
22 uF
C2a
C1206
1k
R4b
1 2
J20
power_switch
D2
BAT60
0.1 uF
C9
0.1 uF
C6
0.1 uF
C4
10 uF
C5
C1206
22 uF
C8
C1206
L1 10 uH
IN
8
SW
6
SW
7
COMP
1
FB
2
SHDN
3
GND
4
GND
5
ROSC
9
SS
10
PAD
11
U1 SC4501
0.1 uF
C10
20k
R11
2.2 nF
C11
120k
R8
20k
R9
20k
R10
VBOOSTVBAT
100 uF
C7b
10 uF
C7a
C1206
D2b
BAT60
D2c
BAT60
D5
BLUE
1k
R33
D6
5V zener
© 2008 Pololu Corporation
http://www.pololu.com/
Pololu
Pololu 3pi Robot Simplified Schematic Diagram
page 1 of 1
rrc03a
D3a
RED
1kR26a
PD1
D3b
T1
1kR26b
D4a
GREEN
1kR25a
PD7
D4b
T1
1kR25b
Q1
reverse protection
B1
2xAAA
B2
2xAAA
1
2
J7
CHARGE
D1a
BLUE
VBAT
1k
R4a
D1b
T1
1k
R4b
D5
BLUE
1k
R33
D6
5V zener
SW1
POWER
VOUT
VIN
GND
BTN1 BTN2
1 2
J20
pushbutton
power circuit
VOUT
VIN
GND
9.25 V
boost
switching
regulator
VBOOST
VOUT
VIN
GND
5.0 V
linear
regulator
VCC
L2
10 uH
0.1 uF
C18
AVCC
+
+
+
R18
10k
Vss
1
VDD
2
Vo
3
RS
4
R/W
5
E
6
DB0
7
DB1
8
DB2
9
DB3
10
DB4
11
DB5
12
DB6
13
DB7
14
LCD1
LCD8X2
A B
VCC
C
1k
R27
1k
R28
1k
R29
PB1
PB4
PB5
PD7
PD2
PB0
PD4
10k
R22
8x2 character LCD
and user pushbuttons
1 2
J6
20k
R32
20k
R31
VBAT
ADC6
20k
R30
battery voltage
sensing circuit
PC6
PD3
PD6
PB3
VBOOST VCC
MO1
MO2
MO3
MO4
Vcc
20
BIN1
17
AO1
2
AO2
6
BO1
12
BO2
8
BIN2
16
PWMB
15
STBY
19
PGND2
9
PGND2
10
VM1
24
VM2
13
BO2
7
BO1
11
AO2
5
AO1
1
VM3
14
PGND1
4
PGND1
3
GND
18
AIN1
21
AIN2
22
PWMA
23
U9
TB6612FNG
VCC
PD5
M2
M1
0.1 uFC27
0.1 uFC28
motor driver and motors
1 2
3 4
5 6
J1
AVRISP
VCC
PB4
PB5
PB3
PC6
programming
connection
1 3
2
Y1
20 MHz
VCC AVCC
R16
10k
SW2
RESET
0.1 uF
C26
10k
R15
VCC
VCC
PC6
BZ1
BUZZER
PC6 (RESET)
29
PD0 (RXD)
30
PD1 (TXD)
31
PD2 (INT0)
32
PD3 (OC2B/INT1)
1
PD4 (XCK/T0)
2
VCC
6
GND
5
PB6 (XTAL1/TOSC1)
7
PB7 (XTAL2/TOSC2)
8
PD5 (OC0B/T1)
9
PD6 (OC0A/AIN0)
10
PD7 (AIN1)
11
PB0 (CLKO/ICP1)
12
PB1 (OC1A)
13
PB2 (SS/OC1B)
14
PB3 (MOSI/OC2A)
15
PB4 (MISO)
16
PB5 (SCK)
17
AVCC
18
AREF
20
GND
21
PC0 (ADC0)
23
PC1 (ADC1)
24
PC2 (ADC2)
25
PC3 (ADC3)
26
PC4 (ADC4/SDA)
27
PC5 (ADC5/SCL)
28
GND
3
VCC
4
ADC6
19
ADC7
22
GND
33
U3
ATmega168
PD3
PD5
PD6
PB3
PB4
PB5
PD7
PB0
PB1
PD2
PD4
1 2
J4
U6
220
R14
PC2
VCC
2.2 nF
C23
U7
220
R17
PC3
VCC
2.2 nF
C24
U8
220
R19
PC4
VCC
2.2 nF
C25
U5
220
R13
PC1
VCC
2.2 nF
C22
U4
220
R12
PC0
VCC
2.2 nF
C21
VBOOST
Q4
47k
R23
LEDON
VCC
220
R21
1 2
J5
220
R20
PC5
ADC6
ADC7
PD0
PD1
reflectance
sensor array
and IR LED
control
microcontroller
D3a
RED
2.21kR26a
PD1
D3b
T1
2.21kR26b
D4a
GREEN
2.21kR25a
PD7
D4b
T1
2.21kR25b
Q1
reverse protection
B1
2xAAA
B2
2xAAA
1
2
J7
CHARGE
D1a
BLUE
VBAT
1k
R4a
D1b
T1
1k
R4b
D5
BLUE
1k
R33
D6
5V zener
SW1
POWER
VOUT
VIN
GND
BTN1 BTN2
1 2
J20
pushbutton
power circuit
VOUT
VIN
GND
9.25 V
boost
switching
regulator
VBOOST
VOUT
VIN
GND
5.0 V
linear
regulator
VCC
L2
10 uH
0.1 uF
C18
AVCC
+
+
+
R18
10k
Vss
1
VDD
2
Vo
3
RS
4
R/W
5
E
6
DB0
7
DB1
8
DB2
9
DB3
10
DB4
11
DB5
12
DB6
13
DB7
14
LCD1
LCD8X2
A B
VCC
C
1k
R27
1k
R28
1k
R29
PB1
PB4
PB5
PD7
PD2
PB0
PD4
10k
R22
8x2 character LCD
and user pushbuttons
1 2
J6
20k
R32
20k
R31
VBAT
ADC6
20k
R30
battery voltage
sensing circuit
PC6
PD3
PD6
PB3
VBOOST VCC
MO1
MO2
MO3
MO4
Vcc
20
BIN1
17
AO1
2
AO2
6
BO1
12
BO2
8
BIN2
16
PWMB
15
STBY
19
PGND2
9
PGND2
10
VM1
24
VM2
13
BO2
7
BO1
11
AO2
5
AO1
1
VM3
14
PGND1
4
PGND1
3
GND
18
AIN1
21
AIN2
22
PWMA
23
U9
TB6612FNG
VCC
PD5
M2
M1
0.1 uFC27
0.1 uFC28
motor driver and motors
1 2
3 4
5 6
J1
AVRISP
VCC
PB4
PB5
PB3
PC6
programming
connection
1 3
2
Y1
20 MHz
VCC AVCC
R16
10k
SW2
RESET
0.1 uF
C26
10k
R15
VCC
VCC
PC6
BZ1
BUZZER
PC6 (RESET)
29
PD0 (RXD)
30
PD1 (TXD)
31
PD2 (INT0)
32
PD3 (OC2B/INT1)
1
PD4 (XCK/T0)
2
VCC
6
GND
5
PB6 (XTAL1/TOSC1)
7
PB7 (XTAL2/TOSC2)
8
PD5 (OC0B/T1)
9
PD6 (OC0A/AIN0)
10
PD7 (AIN1)
11
PB0 (CLKO/ICP1)
12
PB1 (OC1A)
13
PB2 (SS/OC1B)
14
PB3 (MOSI/OC2A)
15
PB4 (MISO)
16
PB5 (SCK)
17
AVCC
18
AREF
20
GND
21
PC0 (ADC0)
23
PC1 (ADC1)
24
PC2 (ADC2)
25
PC3 (ADC3)
26
PC4 (ADC4/SDA)
27
PC5 (ADC5/SCL)
28
GND
3
VCC
4
ADC6
19
ADC7
22
GND
33
U3
ATmega168
PD3
PD5
PD6
PB3
PB4
PB5
PD7
PB0
PB1
PD2
PD4
1 2
J4
U6
220
R14
PC2
VCC
2.2 nF
C23
U7
220
R17
PC3
VCC
2.2 nF
C24
U8
220
R19
PC4
VCC
2.2 nF
C25
U5
220
R13
PC1
VCC
2.2 nF
C22
U4
220
R12
PC0
VCC
2.2 nF
C21
VBOOST
Q4
47k
R23
LEDON
VCC
220
R21
1 2
J5
220
R20
PC5
ADC6
ADC7
PD0
PD1
reflectance
sensor array
and IR LED
control
microcontroller
0.1 uF
C32