Difference between revisions of "AS1531"
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== Use it == | == Use it == | ||
=== modprobe === | === modprobe === | ||
| − | To use the ADC first load | + | To use the ADC, first load hwmon and as1531 modules: |
<pre class="apf"> | <pre class="apf"> | ||
Revision as of 16:16, 2 May 2011
Introduction
AS1531 is a 8 channels 12bits analog do digital converter made by Austriamicrosystem. The driver is included in ARMadeus distribution and can be used with the APF51Dev board.
Soldering
AS1531 chip use a SPI bus to communicate with the microprocessor, then to use it on APFx board it must be connected to a SPI bus.
On the APF51Dev, the AS1531 is connected to the SPI1 bus by default, so you can move to next chapter.
On the APF27-Dev board it can be soldered on SPI3 bus, which is availbale on connector J8.
| J8 pin | AS1531 pin |
|---|---|
| SD1_D0_SPI3_MISO | DOUT |
| SD1_D3_SPI3_SS | CSN |
| SD1_CMD_SPI3_MOSI | DIN |
| SP1_CLK_SPI3_SCLK | SCLK |
Driver
Driver is by default included if you choose an APF51 as target.
Otherwise, you can select it that way:
[ ] $ make linux26-menuconfig
Device Drivers --->
<M> Hardware Monitoring support --->
<M> Austria Microsystems AS1531 Analog to Digital Converter
Then compile the distribution :
[ ] $ make linux26 && make
Use it
modprobe
To use the ADC, first load hwmon and as1531 modules:
# modprobe hwmon # modprobe as1531
read values
# cd /sys/bus/spi/devices/spi0.0/ # ls driver in1_input in4_input in7_input modalias subsystem hwmon in2_input in5_input in_max name uevent in0_input in3_input in6_input in_min power
or:
# cd /sys/class/hwmon/hwmon0/device/ # ls driver in1_input in4_input in7_input modalias subsystem hwmon in2_input in5_input in_max name uevent in0_input in3_input in6_input in_min power
To read adc value just «cat» an input :
# cat in5_input 887
All values read are in milivolts.
