42 lines
977 B
Plaintext
42 lines
977 B
Plaintext
|
Current Sense Shunt
|
||
|
|
===================
|
||
|
|
|
||
|
|
When an io-channel measures the voltage over a current sense shunt,
|
||
|
|
the interesting measurement is almost always the current through the
|
||
|
|
shunt, not the voltage over it. This binding describes such a current
|
||
|
|
sense circuit.
|
||
|
|
|
||
|
|
Required properties:
|
||
|
|
- compatible : "current-sense-shunt"
|
||
|
|
- io-channels : Channel node of a voltage io-channel.
|
||
|
|
- shunt-resistor-micro-ohms : The shunt resistance in microohms.
|
||
|
|
|
||
|
|
Example:
|
||
|
|
The system current is measured by measuring the voltage over a
|
||
|
|
3.3 ohms shunt resistor.
|
||
|
|
|
||
|
|
sysi {
|
||
|
|
compatible = "current-sense-shunt";
|
||
|
|
io-channels = <&tiadc 0>;
|
||
|
|
|
||
|
|
/* Divide the voltage by 3300000/1000000 (or 3.3) for the current. */
|
||
|
|
shunt-resistor-micro-ohms = <3300000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
&i2c {
|
||
|
|
tiadc: adc@48 {
|
||
|
|
compatible = "ti,ads1015";
|
||
|
|
reg = <0x48>;
|
||
|
|
#io-channel-cells = <1>;
|
||
|
|
|
||
|
|
#address-cells = <1>;
|
||
|
|
#size-cells = <0>;
|
||
|
|
|
||
|
|
channel@0 { /* IN0,IN1 differential */
|
||
|
|
reg = <0>;
|
||
|
|
ti,gain = <1>;
|
||
|
|
ti,datarate = <4>;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
};
|