Ten Daily Electronic Common Sense-Section 52

What are the basic characteristics of Philips’ SJAl000?

1. It is pin compatible with PCA82C200 independent CAN controller.
2. It is electrically compatible with PCA82C200 independent CAN controller.
3. PCA82C200 mode is the default Basic CAN mode.
4. Extended receive buffer (64-byte first-in, first-out FIFO).
5. Compatible with CAN 2.0B protocol (passive extension frame in PCA82C200 compatibility mode).
6. Supports 11-bit standard identifier format and 29-bit extended identifier format at the same time.
7. The bit rate can reach 1 Mbps.
8. 24 MHz clock frequency.
9. Supports interface modes of various microprocessors.
10. Programmable CAN output driver configuration.
11. Adapt to the environment of automobile use: -40～125℃.

12.PeliCAN mode extension function:

• Error counters for read/write access
• Programmable error alarm limits
  ——Latest error code register
• Interrupt can be triggered for each CAN bus error
• Arbitration loss interrupt controlled by specific control bit
  -Single transmission (no retransmission)
• Has a listen-only mode (no acknowledgement, no active error flags)
• Support hot swap (software bit rate detection)
• Acceptance filter extension (4B code, 4B shield)
  ——Self-information reception (self-reception request)

What are the commonly used photon detectors?

Commonly used photon detectors include photoconductive detectors, photovoltaic detectors, photoelectric detectors and photoelectron emitters.

What features does FlexRay offer that are not available in traditional in-vehicle communication protocols?

1. 2×10Mb/s data transfer rate
2. Synchronized time base
3. Knowing the arrival time of messages
4. Redundant and non-redundant communication
5. Flexibility

Why is the current digital oscilloscope level not enough to completely replace the analog oscilloscope?

• The continuity of the operation of the digital oscilloscope is not as good as that of the analog oscilloscope. Since any function of a digital oscilloscope is processed digitally by a microprocessor, as opposed to an analog oscilloscope that has no delay. Digital oscilloscopes have more or less the problem of delay between operation and response, and this delay is more pronounced with lower-end scopes.
• A digital oscilloscope cannot measure weak electrical signals. When actually using a digital oscilloscope, we will find that when measuring weak electrical signals, the digital oscilloscope will fail to measure _halo=. The culprit is that a large amount of noise is generated in the digital oscilloscope during digital processing, and when the signal is small, the signal-to-noise ratio becomes particularly low, and the measured signal is submerged in the oscilloscope’s own noise, which seriously affects the signal. Measurement.

How to measure the sensitivity of the label at different angles?

The steps are to first set the transmitter power of the reader to ensure that the electric field strength value at the tag is 0V/m, and then change the horizontal and vertical angles of the tag corresponding to the reader antenna. With the change of the angle, the transmit power needs to be changed to ensure writing data; record the minimum electric field intensity value EMin_write of the write tag in the 860-960MHz frequency band at each angle. This makes it possible to measure the sensitivity of the tag at different angles.

What are the main parameters of the humidity sensitive Resistors?

1. Relative humidity: Relative humidity refers to the ratio of the actual density of water vapor contained in the air to the saturated density at the same temperature at a certain temperature, usually expressed as “RH”. For example, 20%RH means that the relative humidity of the air is 20%.
2. Humidity temperature coefficient: The humidity temperature coefficient refers to the change amount of the humidity indication of the humidity sensitive resistor when the temperature changes by 1 °C when the ambient humidity is constant.
3. Sensitivity: Sensitivity refers to the resolution with which the humidity sensitive resistor detects humidity.
4. Humidity measurement range: The humidity measurement range refers to the humidity measurement range of the humidity sensitive resistor.
5. Wet hysteresis effect: Wet hysteresis effect refers to the hysteresis phenomenon of the electrical parameters of the humidity sensitive resistor in the process of moisture absorption and dehumidification.
6. Response time: The response time refers to the change of the resistance value (reaction speed) of the humidity sensitive resistor when the humidity detection environment changes rapidly.

How does the Auxiliary Pulse Width Modulation (APWM) mode operate when active high?

CMP=0x00000000, continuous period of output low level (0% duty cycle).
CMP=0x00000001, output high level for 1 cycle; CMP=0x00000002, output high level for 2 cycles.
CMP=PERIOD, except for one cycle (less than 100% duty cycle), the output is high.
CMP=PERIOD 1, output high level for the whole cycle (100% duty cycle).
CMP>PERl0D 1, the whole cycle outputs high level.

How to use the Resistors correctly?

In electronic circuits, in order to control voltage and current, resistors are used. Resistors are often called resistors.
There are many types of resistors, which are divided into three types: fixed resistors, variable resistors and potentiometers. Unit labeling rules for resistors and potentiometers in circuit diagrams.
If the resistance value is above megohm, mark the unit M. For example, 1 megohm, marked 1M; 2.7 megohm, marked 2.7M.
The resistance value is between 1 kiloohm and 100 kiloohm, marked with the unit k. For example, 5.1 kΩ, marked 5.1k; 68 kΩ, marked 68k.
The resistance value is between 100 kiloohms and 1 megohm, and can be marked with the unit k or the unit M. For example, 360 kiloohms can be marked with 360k or 0.36M.
The resistance value is below 1 kiloohm, and the unit can be marked with Ω or not. For example, 5.1Ω can be marked with 5.1Ω or 5.1; 680Ω can be marked with 680Ω or 680.
Common sense in the use of resistors. The type and error of the resistor should be selected according to the requirements of the circuit. In general circuits, it is enough to use carbon film resistors with an error of 10% or even 20%. The rated power of the resistor should be equal to 1.5~2 times the actual withstand power to ensure that the resistor is durable and reliable. Before installing the resistor into the circuit, verify its resistance value with the ohmmeter of the multimeter. When installing, it is necessary to make the symbols such as the type and resistance value of the resistor easy to see for verification.

What is included in the MSCAN initialization process?

1. If the MSCAN module is currently running, put it into sleep mode;
2. Enter the initialization mode;
3. Set the corresponding registers, namely CANCTL1, CANBTR0, CANBTR1, CANIDAC, CAN1-DAR0~CANIDAR7, CANIDMR0~ CANIDMR7;
4. Clear INITRQ to leave the initialization mode and return to the normal mode;
5. If the sleep mode was previously entered, leave the sleep mode;
6. Set the remaining MSCAN registers, you can set canctl0, cannier, Cantier et al.

What are the steps in the inkjet process for inkjet printers using piezoelectric technology?

First, the piezoelectric element shrinks under the control of the signal, and the stable state determines the size of the ink droplet;
The piezoelectric element then begins to extend outward, pushing the droplet out of the nozzle, firing the droplet precisely;
Finally, at the moment when the ink droplets are about to fly away from the nozzle, the piezoelectric element returns to its normal state, stops vibrating, and shrinks the ink level back from the nozzle.