R1 10K

2

4

1

3

5

PROG_LOAD

CONN1

1 Rst(PC6)

13 PD7 (AIN1)

12 PD6 (AIN0)

11 PD5 (T1)

6 PD4 (T0)

5 PD3 (INT1)

4 PD2 (INT0)

3 PD1 (TXD)

2 PD0 (RXD)

14 PB0(ICP1)

28(SCL)PC5

27(SDA)PC4

26(ADC3) PC3

25(ADC2) PC2

24(ADC1) PC1

23(ADC0) PC0

19(SCK) PB5

18(MISO) PB4

17(MOSI) PB3

16(OC1B) PB2

15(OC1A) PB1

ATMEGA8

7 Vcc

8 GND

9 PB6(XTAL1)

PB7(XTAL2)10

20AVcc

22AGND

21AREF

U1

C1 100nF

Vcc

Vcc5V

Mini Voltmeter module with 3 digit LED display

2

1

CONN2

Ry

yK

Rx

xK

180R4

+

-

7 se

gmen

t com

mon

cat

ode:

SC

56-1

1GW

A

2

4

6

8

1

3

5

7

10

9

DISP1

a

d

e

f

b

c

g

dp

gnd

gnd

1

3

2

BC547

Q1

Vcc

2

4

6

8

1

3

5

7

10

9

DISP2

7 se

gmen

t com

mon

cat

ode:

SC

56-1

1GW

A

a

d

e

f

b

c

g

dp

gnd

gnd

2

4

6

8

1

3

5

7

10

9

DISP3

7 se

gmen

t com

mon

cat

ode:

SC

56-1

1GW

A

a

d

e

f

b

c

g

dp

gnd

gnd

1

3

2

BC547

Q21

3

2

BC547

Q3

4K7R5

GND

SCK

MISO

MOSI

RST

180R6

180R7

180R8

180R9

180R10

180R11

4K7R12

4K7R13

(c) Guido Socher, tuxgraphics.org

C2

10uF

Vcc5V

2

1

CONN3

2

4

6

8

1

3

5

7

CONN4

Analog Voltage IN

Generic IO port

DC IN: 4.5-5.5V 150mA

2 1

J1

R14

180

2 1 J2

Jumpers for optional decimal pointselection:

C3

100nF