Hardware Reference
In-Depth Information
To +9-12V DC supply
Figure 7-5
XBee radio connected to a gas
sensor. The MQ-6 is shown here,
but the same circuit will work
for many of the Hanwei sensors.
You may have to change the
10K resistor to adjust the output
voltage range, however.
7805
+5V Voltage Reg
In
Out
A
H
Hanwei
MQ-6
Gas Sensor
The XBee shown on the bread-
board below is mounted on a
breakout board. The XBee's pins
will not fit into a breadboard
without the breakout board.
H
B
Xbee Radio
LD1117-33V
Voltage Reg
In
Out
Vcc
AD0 / DIO0
8
Many of the projects in this chapter
are made using the LD1117-33V 3.3V
voltage regulator. The pins on this
regulator are configured differently
from the pins on the other regulators
used in this topic. Check the data
sheet for your regulator to be sure
you have the pins correct. You should
make a habit of checking this because,
otherwise, you will damage your
regulator or other parts of your circuit.
TX
AD1 / DIO1
10K
Ω
RX
AD2 / DIO2
10µF
1µF
DO8
AD3 / DIO3
RTS / AD6 / DIO6
Ass't / AD5 / DIO5
Vref
SLP
CTS / DIO7
RESET
PWM0 / RSSI
220
Ω
PWM1
NC
220
Ω
DTR/DI8
GND
AD4 / DIO4
5V
VREG
3.3V
VREG
1
5
10
15
20
25
30
A
B
C
D
E
F
G
H
I
J
1
5
10
15
20
25
30
