Web voltmeter is voltmeter with
integrated web
server in it. The voltmeter can
operate stanalone and doesn't need any additional PC. It has its own IP
address so it can be accessed via web browser from any place in the
world. It also has two inputs and so can measure voltage from two
sources in paralel.
 |
Web Voltmeter +
thermometer
Range : 0 - 50 V
| Usage
: |
Technical
parameters: |
| Remote measurement of voltage over
internet.
Voltage values are displayed in web browser. Voltmeter has 2
independent inputs 0-50 V. |
Size :
Impedance :
Lienarity :
Speed : |
65
x 55 mm
1 MOhtm
0,2 %
20 times/sec
|
Power
suply : + 5V from external power supply ( 140 mA/ 5V )
Software
: embedded web server ( firmware ) , bootloader
4
inputs : 2 inputs for voltage measurement + 2 inputs for
thermometer
|
Voltmeter is designed with regard
to achieve good electrical parameters with the minimum requirements for
hardware. It has a high input resistance and very good accuracy of
measurement.
Features
:
- 0,5 Mbit on board serial flash for web
pages storage
- Complete web server and TCP/IP stack
- Cookies, Authentication, SMTP, SNTP
- 2 inputs for voltage measurement ( range : 0 - 50V )
- 2 inputs for temperature measurement ( -55 C to 125 C ) |
- own DHCP and FTP server
- remote management (using SNMP protocol) , MIB file support
- mail
sending possibility
- bootloader ( allows to load data + soft via FTP )
- low current consuption ( typically 140 mA/ 5V )
|
Web voltmeter allows settings various parameters. Further description
comming soon.
Web site
Displaying data in web
site
Measured data can be
displayed in web
browser.Refresh period is 0.5s by default (the value is settable). Web
server uses AJAX technology, so only small ammout of data is
transfered.Therefor page refreshing is quite quick. Any known web
browswer is supported : Microsoft IE, Mozila, Chrome etc...
Web site in EEPROM
Web page code is stored in extern EEPROM and user can easyly modify it.
First the page needs to be transformed using small utility to bin
format and afterwards transfered via FTP to EEPROM. Software for
microcontroller cannot be changed ( firmware ).
|
|

|
Web server features
Web server setup..
Web server setup has many posibilities. Used TCP/IP stack from
Microchip company has many funcions included.
More about web server setup see in Microchip TCP/IP Stack. For web
server a microcontroller PIC18F67J60 is used.
Web Voltmeter.
Electrical characteristics of the voltmeter are the same as in USB
version ( refer to USB voltmeter ).For voltage mesurement built-in A/D
converter of the microprocesor is used. It's a 10-bit A/D converter
with very good characteristics. The voltmeter has two input channels by
default but the number can be increased up to 10 chanels, but HW
modification are needed.
Web thermometer.
For temperature measurement there are 2 connectors for teperuture
sensors with DS18S20. Teperature mesurement is very accurate ( max.
0,5C tolerance ). The module allows to mesure teperature from two
independant sources in paralel. Temperature imputs can also be easyly
increased.
More picture
Another voltmeters.
Another types of voltmeters on this page are: usb voltmeter and
wireless voltmeter.