The parameters listed below are only valid if certain kernel build options were enabled and if respective hardware is present. The text in square brackets at the beginning of each description states the restrictions within which a parameter is applicable: CLK Common clock infrastructure is enabled.
Whether it be temperature, pressure, voltage, etc, their variation is always analog in nature. This is an analog data. Signal Acquisition Process Now, we must process the data that we have received. But analog signal processing is quite inefficient in terms of accuracy, speed and desired output.
Signal Acquisition Process In general, the signal or data acquisition process has 3 steps. In the Real World, a sensor senses any physical parameter and converts into an equivalent analog electrical signal. For efficient and ease of signal processing, this analog signal is converted into a digital signal using an Analog to Digital Converter ADC.
This digital signal is then fed to the Microcontroller MCU and is processed accordingly. Hence we need to use ADC. For simple circuits, comparator op-amps can be used.
Some other features of the ADC are as follows: In this case, any analog value in between 0 and 5V is converted into its equivalent ADC value as shown above. This is the basic concept of ADC. This interval is determined by the clock frequency. So to achieve it, frequency division must take place.
The prescaler acts as this division factor. It produces desired frequency from the external higher frequency. There are some predefined division factors — 2, 4, 8, 16, 32, 64, and Now, the major question is… which frequency to select?
Out of the 50kHzkHz range of frequencies, which one do we need? Well, the answer lies in your need. There is a trade-off between frequency and accuracy.
Greater the frequency, lesser the accuracy and vice-versa. ADC Registers We will discuss the registers one by one. In any case, we will discuss all the bits one by one.
The following combinations are used. For this, choose the first option. Apart from this case, you can either connect a capacitor across AREF pin and ground it to prevent from noise, or you may choose to leave it unconnected.
Or else, choose the last option for internal Vref. We will discuss about this a bit later. Which one do we choose? You can choose it by setting these bits. However, we are concerned only with the first 8 conditions. Initially, all the bits are set to zero. This 1 is written as long as the conversion is in progress, after which it returns to zero.The commands attr, deleteattr, displayattr, delete, get, list, set, setreading, setstate, trigger can take a more complex device specification as argument, which will be expanded to a list of devices.
A device specification (short devspec) can be: a single device name. This is the most common case. a list of devices, separated by comma (,).
The eighth bit is the read/write flag where 0 indicates a write and 1 indicates a read. Figure 1: 7-bit addressing.
The I2C bus specification specifies that in standard-mode I2C, the slave address is 7-bits long followed by the read/write bit. Based on kernel version Page generated on EST.. 1 Kernel Parameters 2 ~~~~~ 3 4 The following is a consolidated list of the kernel parameters as 5 implemented by the __setup(), core_param() and module_param() macros 6 and sorted into English Dictionary order (defined as ignoring all 7 punctuation and sorting digits before letters in a case insensitive 8 manner), and with.
An I2C transaction is either (all) read or (all) write.
Hence for an I2C slave device that has more than 1 register and that wants to support individual reading of those registers, there must be a mechanism to specify the address of the register that is read.
The address, read, and write commands take a parameter P. Normally P is one byte (). If the command is preceded by the Escape command then P is two bytes (, least significant byte first). I am trying to read/update I2C address of a device.
However, in order to do that during the communication state of pin LDAC has to be changed, as shown in the manual: Is .