OTHER
This system is designed to run on a 9.0 V battery. It
sensor, microcontroller, and LCD. The battery is mounted on
the back of the board using a space saving spring battery clip.
contains a 5.0 V regulator to provide 5.0 V to the pressure
Table 2. Parts List
Ref.
U2
C1
C2
C3
D1
D2
S2, S3
U1
U3
U4
R1
R2
R3, R6
R4, R5
R7, R8
R9, R10
U6
U5
Qty
1
1
1
1
1
1
2
1
1
1
1
1
2
2
2
2
1
1
Description
Pressure Sensor
Vcc Cap
Op-Amp Cap
Shift Register Cap
Red LED
Green LED
Pushbuttons
Quad Op-Amp
Voltage Regulator
Microcontroller
? W Resistor
? W Resistor
? W Resistor
? W Resistor
? W Resistor
? W Resistor
LCD (Optional)
Shift Registor
Value
1
0.1 μ f
0.1 μ f
0.1 μ f
5.0 V
8-pin
22 K
2.4 K
1.2 M
1.5 K
10 K
1.0 K
16 x 2
Vendor
Freescale
Generic
Generic
Generic
Generic
Generic
Generic
ADI
Fairchild
Freescale
Generic
Generic
Generic
Generic
Generic
Generic
Seiko
Texas Instruments
Part No.
MPXM2010GS
AD8544
LM78L05ACH
MC68HC908QT4
L168200J000
74HC164
Smart Washer Software
This application note describes the first software version
available. However, updated software versions may be
available with further functionality and menu selections.
Software User Instructions
When the system is turned on or reset, the microcontroller
will flash the selected LED and display the program title on the
LCD for five seconds, or until the select (SEL) button is
pushed. Then the menu screen is displayed. Using the select
(SEL) pushbutton, it is easy to scroll through the menu options
for a software program. To run the water level program, use
the select button to highlight the Water Level option, then
press the enter (ENT) pushbutton. The Water Level program
will display current water level, the rate of flow, a message if
the container is Filling , Emptying , Full , or Empty , and a
scrolling graphical history displaying data points representing
the past forty level readings.
The Water Level is displayed by retrieving the digital
voltage from the internal A/D Converter. This voltage is
converted to pressure in millimeters of water and then
displayed on the LCD.
Calibration and Calibration Software
To calibrate the system, a two-point calibration is
performed. The sensor will take a calibration point at 0 mm
buttons on system power-up enters the calibration mode. At
this point, the calibration menu is displayed with the previously
sampled offset voltage. To recalibrate the system, expose the
sensor to atmospheric pressure and press the SEL button
(PB1). At this point, the zero offset voltage will be sampled and
saved to a location in the microcontroller memory. To obtain
the second calibration point, place the end of the plastic tube
from the pressure sensor to the bottom of a container holding
40 mm of water. Then press the ENT button (PB2). The
voltage output will be sampled, averaged and saved to a
location in memory. To exit the calibration mode, press the
SEL (PB1) button.
Figure 5. Water Level System Set-Up
for Demonstration
and at 40 mm of water. Depressing both the SEL and ENT
AN1950
Sensors
4
Freescale Semiconductor
相关PDF资料
KN500B1/4 SWITCH KNOB STRAIGHT .50" BLACK
KN5700B1/4 SWITCH KNOB STRAIGHT .75" BLACK
KN700B1/4 SWITCH KNOB STRAIGHT .75" BLACK
KS-100 PROTECTIVE COVER FOR RELAYS
KTKK-0500 CONN HEAT SHRINK TUBE SZ 8 STR
KTKK-0674 CONN HEAT SHRINK TUBE SZ E STR
KTKK-1123 CONN HEAT SHRINK TUBE SZ D ANG
KTR10EZPJ302 RES 3.0K OHM 1/8W 5% 0805 SMD
相关代理商/技术参数
KITMPXA6115AEVB 功能描述:压力传感器开发工具 Sensor Toolbx Pressu Sensor Developmt brd RoHS:否 制造商:Freescale Semiconductor 工具用于评估:MPL3115A2 接口类型:USB 最大工作温度:
KITMPXSHOWEVK 功能描述:压力传感器开发工具 PRESSURE SHOWBOARD RoHS:否 制造商:Freescale Semiconductor 工具用于评估:MPL3115A2 接口类型:USB 最大工作温度:
KITMPXV5004DPEVB 功能描述:压力传感器开发工具 MPXV5004 Dev Kit RoHS:否 制造商:Freescale Semiconductor 工具用于评估:MPL3115A2 接口类型:USB 最大工作温度:
KITMS05051 功能描述:电容套件 0.2pF-1.0pF 0505 10 EA-8 VALUES RoHS:否 制造商:Nichicon 电容范围:10 uF to 680 uF 公差范围: 电压范围:6.3 V to 25 V 产品:Aluminum Organic Polymer Capacitor Kit
KITMS05052 功能描述:电容套件 1.5pF-22pF 0505 10 EA-8 VALUES RoHS:否 制造商:Nichicon 电容范围:10 uF to 680 uF 公差范围: 电压范围:6.3 V to 25 V 产品:Aluminum Organic Polymer Capacitor Kit
KITMS05053 功能描述:电容套件 27pF-330pF 0505 10 EA-8 VALUES RoHS:否 制造商:Nichicon 电容范围:10 uF to 680 uF 公差范围: 电压范围:6.3 V to 25 V 产品:Aluminum Organic Polymer Capacitor Kit
KITMS06031 功能描述:电容套件 0.1pF-1.0pF 0603 10 EA-8 VALUES RoHS:否 制造商:Nichicon 电容范围:10 uF to 680 uF 公差范围: 电压范围:6.3 V to 25 V 产品:Aluminum Organic Polymer Capacitor Kit
KITMS06032 功能描述:电容套件 1.5pF-22pF 0603 10 EA-8 VALUES RoHS:否 制造商:Nichicon 电容范围:10 uF to 680 uF 公差范围: 电压范围:6.3 V to 25 V 产品:Aluminum Organic Polymer Capacitor Kit