Difference between revisions of "AS1531"
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== Introduction == | == Introduction == | ||
| − | AS1531 is a 8 channels | + | AS1531 is a 12bits 8 channels Analog to Digital Converter made by [http://www.austriamicrosystems.com/ Austriamicrosystem]. Its use a SPI bus to communicate with a master microprocessor. A driver is included in the Armadeus BSP/SDK and can be used on the APF51Dev board. |
| − | == | + | == Connecting chip on APF boards == |
| − | AS1531 | + | * On the [[APF51Dev]], the AS1531 is connected to the SPI1 bus by default, so you can move to [[AS1531#Use_it|next chapter]]. |
| + | * On the [[APF27Dev]] board it can be soldered on SPI3 bus, which is available on connector J8. | ||
{| class="wikitable" style="text-align:center; width:50%;" | {| class="wikitable" style="text-align:center; width:50%;" | ||
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== Driver == | == Driver == | ||
| − | + | * Driver is by default included if you choose an [[APF51]] as target. | |
| − | + | * Otherwise, you can select it that way: | |
<pre class="host"> | <pre class="host"> | ||
| − | + | $ make linux-menuconfig | |
</pre> | </pre> | ||
| Line 41: | Line 42: | ||
</pre> | </pre> | ||
| − | + | * Then rebuild the Linux and rootfs images: | |
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
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| − | Then | + | |
<pre class="host"> | <pre class="host"> | ||
| − | + | $ make linux && make | |
</pre> | </pre> | ||
== Use it == | == Use it == | ||
| − | + | {{Warning|AS1531 is used with internal reference voltage of 2,5V, so DO NOT TRY to acquire signals with greater voltage range.}} | |
| − | + | ||
| − | <pre class=" | + | === Load driver === |
| − | + | To use the AS1531, first load ''as1531'' module: | |
| − | + | ||
| − | + | <pre class="apf"> | |
| + | # modprobe as1531 | ||
</pre> | </pre> | ||
| − | === | + | === Read channels value === |
| − | + | ||
| − | + | ||
<pre class="apf"> | <pre class="apf"> | ||
| − | # cd /sys/bus/spi/devices/ | + | # cd /sys/bus/spi/devices/spi0.0/ |
# ls | # ls | ||
driver in1_input in4_input in7_input modalias subsystem | driver in1_input in4_input in7_input modalias subsystem | ||
| Line 91: | Line 77: | ||
To read adc value just «cat» an input : | To read adc value just «cat» an input : | ||
<pre class="apf"> | <pre class="apf"> | ||
| − | # cat in5_input | + | # cat in5_input |
887 | 887 | ||
</pre> | </pre> | ||
All values read are in milivolts. | All values read are in milivolts. | ||
| + | [[Category:ExternalDeviceControl]] | ||
| + | [[Category:Linux drivers]] | ||
| + | [[Category:Analog to Digital Converter]] | ||
| + | |||
| + | ==Examples== | ||
| + | * Script to read all values each 500ms and display them on console: | ||
| + | <source lang="bash"> | ||
| + | #!/bin/sh | ||
| + | |||
| + | modprobe as1531 | ||
| + | |||
| + | loop=1 | ||
| + | while [ "$loop" == 1 ]; do | ||
| + | for i in 0 1 2 3 4 5 6 7; do | ||
| + | value=`cat /sys/bus/spi/devices/spi0.0/in"$i"_input` | ||
| + | echo -n "$value " | ||
| + | done | ||
| + | usleep 500000 # 500ms | ||
| + | echo | ||
| + | done | ||
| + | </source> | ||
Latest revision as of 19:13, 12 February 2013
Contents
Introduction
AS1531 is a 12bits 8 channels Analog to Digital Converter made by Austriamicrosystem. Its use a SPI bus to communicate with a master microprocessor. A driver is included in the Armadeus BSP/SDK and can be used on the APF51Dev board.
Connecting chip on APF boards
- On the APF51Dev, the AS1531 is connected to the SPI1 bus by default, so you can move to next chapter.
- On the APF27Dev board it can be soldered on SPI3 bus, which is available 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 linux-menuconfig
Device Drivers --->
<M> Hardware Monitoring support --->
<M> Austria Microsystems AS1531 Analog to Digital Converter
- Then rebuild the Linux and rootfs images:
$ make linux && make
Use it
 |
Warning: AS1531 is used with internal reference voltage of 2,5V, so DO NOT TRY to acquire signals with greater voltage range. |
Load driver
To use the AS1531, first load as1531 module:
# modprobe as1531
Read channels value
# 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.
Examples
- Script to read all values each 500ms and display them on console:
#!/bin/sh
modprobe as1531
loop=1
while [ "$loop" == 1 ]; do
for i in 0 1 2 3 4 5 6 7; do
value=`cat /sys/bus/spi/devices/spi0.0/in"$i"_input`
echo -n "$value "
done
usleep 500000 # 500ms
echo
done
