Hardware/CubeSat Gumstix/Test/ADC
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Revision as of 16:26, 26 October 2015 by Francois.corthay (Talk | contribs)
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The ADC controller design reads the 8 ADC channels together with the temperature value and sends the values to the serial port.
The UART baud rate is 115˙200. The ADC sampling rate is 100 Hz, due to the slow UART text transmission. The ADC's SPI connection runs at 12.5 MHz (100 MHz / 4 / 2).
SPI
The ADC's SPI interface is mirrored on the peripheral 2 connector:
- CS_n pin 5
- SCLK pin 6
- MOSI pin 7
- MISO pin 8
- RST_N pin 9
- BUSY pin 10
Serial port
The serial data out is provided on the serial port to the Gumstix. It is mirrored on the peripheral 2 connector:
- GND pin 2
- TxD pin 3 (not used)
- RxD pin 4
The FTDI serial-USB adapter uses:
- GND: black
- TxD: orange
- RxD: yellow
Measurements
With a 5 V voltage reference, the reading should be:
- FFFh for the 5 V on channel 0
- A8Fh for the 3.3 V on channels 1 to 3
- 800h for the 2.5 V on channel 1
- 5C2h for the 1.8 V on channel 2
- 3D7h for the 1.2 V on channel 4