LRADC - Revision history

JulienB: /* Use it */

2019-11-25T14:15:26Z

‎Use it

JulienB: /* Read channels value */

2017-02-28T12:07:40Z

‎Read channels value

JulienB: /* Use it */

2016-11-02T23:14:47Z

‎Use it

JulienB at 22:31, 2 November 2016

2016-11-02T22:31:03Z

JulienB: /* Use it */

2016-11-02T22:30:03Z

‎Use it

JulienB: /* Introduction */

2016-11-02T22:27:34Z

‎Introduction

GwenhaelG: /* Load driver */

2013-02-02T17:28:17Z

‎Load driver

GwenhaelG: /* Read channels value */

2013-02-02T16:20:43Z

‎Read channels value

GwenhaelG at 16:08, 2 February 2013

2013-02-02T16:08:21Z

New page

== Introduction ==

This description uses Linux kernel > 3.7.

LRADC is a 12 bits 16 channels Analog to Digital Converter integrated into the iMX28 processor.

Only channels 0-6 may be used to generic conversions and channels 2, 3, 4, 5 are used to the touchscreen.

* Channel 0 is available on pin J10 p.38;
* Channel 1 is available on pin J10 p.36;
* Channel 6 is available on pin J10 p.35;

== Driver ==
Driver is by default included if you choose an [[APF28]] as target.

Otherwise, you can select it that way:

<pre class="host">
[ ] $ make linux-menuconfig
</pre>

<pre class="config">
Device Drivers --->
<M> Staging drivers --->
IIO staging drivers
Analog to digital converters
<M> Freescale i.MX28 LRADC
</pre>

Then compile the distribution :
<pre class="host">
[ ] $ make linux && make
</pre>

== Use it ==

=== Load driver ===
To use the LRADC, first load ''lradc'' module:

<pre class="apf">
# modprobe lradc
</pre>

=== Read channels value ===

<pre class="apf">
# cd /sys/bus/iio/devices/iio:device0
# ls
buffer in_voltage11_raw in_voltage2_raw name
dev in_voltage12_raw in_voltage3_raw power
in_temp8_raw in_voltage13_raw in_voltage4_raw scan_elements
in_temp9_raw in_voltage14_raw in_voltage5_raw subsystem
in_voltage0_raw in_voltage15_raw in_voltage6_raw trigger
in_voltage10_raw in_voltage1_raw in_voltage7_raw uevent
</pre>

To read adc value just «cat» an input :
<pre class="apf">
# cat in_voltage0_raw
4095
</pre>

[[Category:Linux drivers]]
[[Category:Analog to Digital Converter]]

← Older revision		Revision as of 14:15, 25 November 2019
Line 62:		Line 62:

	All values are not converted (ie. directly show the register content). To have the mV value, you must do: value_mV = in_voltageX_raw * 1850/4095		All values are not converted (ie. directly show the register content). To have the mV value, you must do: value_mV = in_voltageX_raw * 1850/4095
		+
		+	===Temperature===
		+	* LRADC is also able to give us i.MX28 die temp:
		+
		+	<pre class="apf">
		+	TEMP_RAW=`cat /sys/bus/iio/devices/iio:device0/in_temp8_raw`
		+	TEMP_OFFSET=`cat /sys/bus/iio/devices/iio:device0/in_temp8_offset`
		+	TEMP_SCALE=`cat /sys/bus/iio/devices/iio:device0/in_temp8_scale`
		+
		+	TEMP=`echo "${TEMP_RAW} ${TEMP_OFFSET} + ${TEMP_SCALE} * p" \| dc`
		+	echo ${TEMP}
		+	</pre>

	==Links==		==Links==

@@ Line 61: / Line 61: @@
 </pre>
-All values are not converted (ie. directly show the register content). To have the mV value, you must doi: value_mV = read_value * 1850/4095
+All values are not converted (ie. directly show the register content). To have the mV value, you must do: value_mV = in_voltageX_raw * 1850/4095
 ==Links==

@@ Line 62: / Line 62: @@
 All values are not converted (ie. directly show the register content). To have the mV value, you must doi: value_mV = read_value * 1850/4095
 [[Category:Linux drivers]]
 [[Category:Analog to Digital Converter]]
 [[Category:Industrial Input Output]]

← Older revision		Revision as of 22:31, 2 November 2016
Line 65:		Line 65:
	[[Category:Linux drivers]]		[[Category:Linux drivers]]
	[[Category:Analog to Digital Converter]]		[[Category:Analog to Digital Converter]]
		+	[[Category:Industrial Input Output]]

@@ Line 36: / Line 36: @@
 === Load driver ===
-To use the LRADC, first load ''lradc'' module:
+To use the LRADC, first load ''mxs-lradc'' module:
 <pre class="apf">
@@ Line 55: / Line 55: @@
 </pre>
-To read adc value just «cat» an input :
+To read ADC value just «cat» the corresponding input file:
 <pre class="apf">
-# cat in_voltage0_raw
+# cat in_voltage0_raw       for channel 0
 </pre>
-All values are not converted (ie. directly the register content). To have the mV value, you must doing: value_mV = read_value * 1850/4095
+All values are not converted (ie. directly show the register content). To have the mV value, you must doi: value_mV = read_value * 1850/4095
 [[Category:Linux drivers]]
 [[Category:Analog to Digital Converter]]

@@ Line 3: / Line 3: @@
 This description uses Linux kernel > 3.7.
-LRADC is a 12 bits 16 channels Analog to Digital Converter integrated into the iMX28 processor.
+LRADC is a 12 bits 16 channels Analog to Digital Converter integrated into the i.MX28 processor.
-Only channels 0-6 may be used to generic conversions and channels 2, 3, 4, 5 are used to the touchscreen.
+Only channels 0-6 may be used to generic conversions and channels 2, 3, 4, 5 are used for the touchscreen on [[APF28Dev]].
-* Channel 0 is available on pin J10 p.38;
+* Channel 0 is available on J10 pin 38 of [[APF28Dev]]
-* Channel 1 is available on pin J10 p.36;
+* Channel 1 is available on J10 pin 36 of [[APF28Dev]]
-* Channel 6 is available on pin J10 p.35;
+* Channel 6 is available on J10 pin 35 of [[APF28Dev]]
 == Driver ==

@@ Line 39: / Line 39: @@
 <pre class="apf">
-# modprobe lradc
+# modprobe mxs-lradc
 </pre>