Below are the main components involved in this project :
PIC16F88
INA125P Amplifier
The INA125P is a low power, high accuracy
instrumentation amplifier with a precision voltage reference. It provides
complete bridge excitation and precision differential-input amplification on a
single integrated circuit. A single external resistor sets any gain from 4 to
10,000. The INA125 is laser-trimmed for low offset voltage (250mV), low offset
drift (2mV/°C), and high
common-mode rejection (100dB at G = 100).
It operates on single (+2.7V to +36V) or dual (±1.35V to±18V) supplies. The
voltage reference is externally adjustable with pin selectable voltages of
2.5V, 5V, or 10V, allowing use with a variety of transducers. The reference
voltage is accurate to ±0.5% (max) with ±35ppm/°C drift (max).Sleep mode allows
shutdown and duty cycle operation to save power.
Load cell Sensor
A load cell is a sensor or a transducer
that converts a load or force acting on it into an electronic signal. This
electronic signal can be a voltage change, current change or frequency change depending
on the type of load cell and circuitry used.
The most common use of this sensor is in
weighing machine. Load cells are used in several types of measuring instruments
such as weighing scales, universal testing machines. Every weighing machine
which shows weight has a load cell as a sensing element.
Load cell in the weighing scale is a
resistive load cell. Resistive load cells work on the principle of
piezo-resistivity. When a load/force/stress is applied to the sensor, it
changes its resistance. This change in resistance leads to a change in output voltage
when a input voltage is applied.
HC11 serial port wireless module
HC11 wireless communication frequency band
is multiple types of serial port transparent transmission modes have respective
features, and the mode is changed by command.
User do not need to program the modules,
and four modes are only responsible for receiving and sending serial port data,
and are convenient to use.
HC11 wireless module is low current consumption;
the idle current is 80μA, 3.5mA or 22mA, depending on the selected mode. The
number of bytes sent to serial port of module unlimited to one time.
For this project, it is used to transmit the data beetween MCU and computer.
USB to UART Converter
Serial communication is most popular
interface between device and this applies to microcontroller and computer. UART
is one of those serial interfaces. Classically, most serial interface from
microcontroller to computer is done through serial port (DB9). However, since
computer serial port used RS232 protocol and microcontroller used TTL UART, a
level shifter is needed between these interfaces. Recently, serial port of
computer have been phase out, it have been replaced with USB. Of course most
developer chooses USB to serial converter to obtain virtual serial port. The
level shifter is still necessary for UART interface.
USB to UART converter offers USB plug and
play, direct interface with microcontroller and it provide low current 5V
supply from USB port. This product offers low cost USB to UART converter to
user. It is easier to connect a microcontroller project to a PC.
It has been designed with capabilities and
features of :
USB Specification v1.1
Tested with the baud rate up to 115200
bps.
Low cost USB to UART converter
Easy to use, aiming development between computer and microcontroller, 3.3V or 5V logic.
USB powered, no external source is required to use this converter
Configurable for 3.3V/5V UART interface
Low cost USB to UART converter
Easy to use, aiming development between computer and microcontroller, 3.3V or 5V logic.
USB powered, no external source is required to use this converter
Configurable for 3.3V/5V UART interface
Easy to use 6 pin interface: TXD, RXD, GND,
DTR, RTS and VCC (5V or 3.3V)
No comments:
Post a Comment