Msp Based Volymeter
MSP430 BASED 30V VOLT METER | | | |
Project overview:
MSP430 BASED 30V VOLT METER:
Introduction:
This is a simple application of internal 10-bit ADC(analog to digital converter) of MSP430G2231 microcontroller.you can use this circuit to measure up to 30 v dc.. the possible applications are on bench top power supply or as a panel meter in various system.
Overview of the project:
Circuit description TEXAS INSTRUMENTS MSP430G2231 is the heart and brain of this circuit .the internal adc of the mcu with a resistor network voltage divider is used to measure the input voltage. Then 3 digest of comm anode 7 segment display is used to display final converted voltage. As you can see in the schematic the displays are multiplexed with each other. means we switch on one display and put the corresponding digit on this while other two displays are off this cycle go for each of the display.
the only problem with MSP430 mcu is there is very less I/O lines are available to use so we need 7 +3 lines to drive the display and maybe one more pin for adc input (if adc input is not multiplexed with other pin) total 10to11 lines are required but we don 't have that much lines from mcu so we have to use 74LS47 bcd to 7segment decoder ic which enable us to display any digit with only 4 i/o lines instead of 7 lines so now we require only 4+3+1 lines total 8 lines. in this circuit the refresh rate is about 50hz.
Voltage Divider Front End
as you can seen in the schematic the 82k resistor and 10 k trim pot is connected ias a voltage divider configuration .we all know very well that by default MSP430 microcontroller ADC reference voltage can be set to 2.5 volts internal reference . so what we have to do is make such voltage divider that can divide out maximum range 30 volts to 2.5 volts . so we need is Vin/12 ==> 30/12 =2.5v voltage divider . and to keep as less as possible attenuation on the under test voltage we have to keep the voltage
Project overview:
MSP430 BASED 30V VOLT METER:
Introduction:
This is a simple application of internal 10-bit ADC(analog to digital converter) of MSP430G2231 microcontroller.you can use this circuit to measure up to 30 v dc.. the possible applications are on bench top power supply or as a panel meter in various system.
Overview of the project:
Circuit description TEXAS INSTRUMENTS MSP430G2231 is the heart and brain of this circuit .the internal adc of the mcu with a resistor network voltage divider is used to measure the input voltage. Then 3 digest of comm anode 7 segment display is used to display final converted voltage. As you can see in the schematic the displays are multiplexed with each other. means we switch on one display and put the corresponding digit on this while other two displays are off this cycle go for each of the display.
the only problem with MSP430 mcu is there is very less I/O lines are available to use so we need 7 +3 lines to drive the display and maybe one more pin for adc input (if adc input is not multiplexed with other pin) total 10to11 lines are required but we don 't have that much lines from mcu so we have to use 74LS47 bcd to 7segment decoder ic which enable us to display any digit with only 4 i/o lines instead of 7 lines so now we require only 4+3+1 lines total 8 lines. in this circuit the refresh rate is about 50hz.
Voltage Divider Front End
as you can seen in the schematic the 82k resistor and 10 k trim pot is connected ias a voltage divider configuration .we all know very well that by default MSP430 microcontroller ADC reference voltage can be set to 2.5 volts internal reference . so what we have to do is make such voltage divider that can divide out maximum range 30 volts to 2.5 volts . so we need is Vin/12 ==> 30/12 =2.5v voltage divider . and to keep as less as possible attenuation on the under test voltage we have to keep the voltage
References: * www.wikipedia.com * www.ti.com * www.circuitvalley.com panel meter: A panel meter is an instrument that displays an input signal in either a digital or analog form. Many panel meters also include alarm options as well as the ability to connect and transfer data to a computer. OMEGA 's iSeries panel meters are available with an ethernet option which allows the panel meter reading to be accessed across a local area network (LAN) or even through the internet. firmware: ex: tv remote. In electronic systems and computing, firmware is the combination of persistent memory and program code and data stored in it.[1] Typical examples of devices containing firmware are embedded systems (such as traffic lights, consumer appliances, and digital watches), computers, computer peripherals, mobile phones, and digital cameras. The firmware contained in these devices provides the control program for the device. Firmware is held in non-volatile memory devices such as ROM, EPROM, or flash memory. Changing the firmware of a device may rarely or never be done during its economic lifetime; some firmware memory devices are permanently installed and cannot be changed after manufacture. Common reasons for updating firmware include fixing bugs or adding features to the device. This may require physically changing ROM integrated circuits[citation needed], or reprogramming flash memory with a special procedure. Firmware such as the ROM BIOS of a personal computer may contain only elementary basic functions of a device and may only provide services to higher-level software. Firmware such as the program of an embedded system may be the only program that will run on the system and provide all of its functions.