Talk:Other Hardware old
Revision as of 08:44, 3 February 2007 by Comm board (talk | contribs) (→External pressure sensor board (altitude))
Internal pressure sensor
needs access to analog grade psu. scp1000-d11, costs 20-21$ and can provide 10cm (3.3") accuracy with 2Hz update or 1mt (3.3 foot) with 7Hz update rate. The resolution is better. Interface is I2C.
External pressure sensor board (altitude)
--Comm board 07:46, 31 January 2007 (CET)
Pressure Sensor: MPXA6115A MPXH6115A
Interface, 3.3V I2C interface, 100khz, attiny as alternative processor.
- MCU pic12f675 or equivalent
- low cost op-amp (not rail2rail)
- 1Mhz voltage doubler
- Precision 5.0V ldo
- 1x pwm output and at the same time ADC input, 0-3.3V
- 1x raw pressure sensor input, div 1.4 for 0-3.3V range (max resolution is 981 units), optional
- 1x offset adc input (raw-pwm_out)*gain(1000)
- Internal temperature sensor for full temperature compensation outside the 0-70degr. range.
- 16 times oversampling