Hi Sailoog and team !
What about associating to each analog input a user defined (in OP tabs) coefficient to calibrate the measuring chain (errors due to either the sensor or distortions due to the hardware linking the sensor to the RPi).
-For 1W sensors, the reading of my 2 BMP180 have more than one degree difference. I know an error of 2°C is meaningless in the coolant temperature, but it is quite significant in sea temp. when going for a swim ...
- Same for I2C sensors (pressure, temperature, humidity)
-For SPI interface, as the input value range of MPC3008 is 0 to 3.3 (or 3.2 ?) V, for a battery voltage supervision (10- 14 V) a divider bridge is required, bringing in more distortion to the reading. To monitor a battery current via a shunt (30 to 50 mV) an amplifier will be needed whose gain will depend on the precision of a couple of resistors ... Of course for an MPC3008 8 coefficients would be reqired.
Of course the HW used to connect a sensor to an input has to adapt the sensor range to the input range, but a SW coefficient would make the calibration process a breeze.
What about associating to each analog input a user defined (in OP tabs) coefficient to calibrate the measuring chain (errors due to either the sensor or distortions due to the hardware linking the sensor to the RPi).
-For 1W sensors, the reading of my 2 BMP180 have more than one degree difference. I know an error of 2°C is meaningless in the coolant temperature, but it is quite significant in sea temp. when going for a swim ...
- Same for I2C sensors (pressure, temperature, humidity)
-For SPI interface, as the input value range of MPC3008 is 0 to 3.3 (or 3.2 ?) V, for a battery voltage supervision (10- 14 V) a divider bridge is required, bringing in more distortion to the reading. To monitor a battery current via a shunt (30 to 50 mV) an amplifier will be needed whose gain will depend on the precision of a couple of resistors ... Of course for an MPC3008 8 coefficients would be reqired.
Of course the HW used to connect a sensor to an input has to adapt the sensor range to the input range, but a SW coefficient would make the calibration process a breeze.
Cordialement
Didier B
Pi4, SSD USB3, OP 3.0 Touch SK 3.2.1 OpenCPN 5.8.4 : Thank you Thank you Thank you
Didier B
Pi4, SSD USB3, OP 3.0 Touch SK 3.2.1 OpenCPN 5.8.4 : Thank you Thank you Thank you