ADC components of OSS-EC
In this section, we will use the OSS-EC ADC component as an example.
- Block diagram of ADC components and OSS-EC software ( fig.1 )
- OSS-EC flowchart for ADC components ( fig.2)
| ｙ | physical value |
| vi | Sensor output signal |
| ai | Circuit output voltage |
| PCMP | Program component of OSS-EC |
| MP | Microcontroller unit program ADC unit program ai = f(ch) |
| CP | Circuit/IC components program Conversion formula from circuit output voltage to sensor output signal value vi = f(ai) |
| SP | System components program Conversion formula from sensor output signal value to physical value y = f(vi) |
The conversion formula for vi shall be as follows.
vi = f(ai) = ai * ADC_vdd / ( 2ADC_bit ）× K_tc
| ADC_Vdd | Sensor supply voltage [V] |
| ADC_bit | ADC conversion of MPU Bit number CAUTION：When Mbed is selected, 16bit is fixed |
| K_tc | Circuit/IC transformer circuit constants |
The conversion formula for y is as follows. ( Liner conversion )
Let it be a linear transformation equation.
y = f(vi) =( vi – x_offset ) / k_gain + y_offset
| x_offset | Voltage Offset [V] |
| k_gain | Voltage/Physical Value Conversion Constant |
| y_offset | physical value Offset |
