adolfbasil › 2022年10月
For the cleaning of hard chips such as glass chips
2022年10月27日
For the cleaning of hard chips such as glass chips, if the surface of the chip channel is not coated, NaOH solution (1mol/L) can be used for cleaning. If the surface of the chip channel has been coated, it cannot be cleaned with a high-concentration alkali solution or acid solution, because the acid or alkali solution will corrode the layer on the surface of the channel with a long time of cleaning. At this time, you can use a low concentration acid or alkali AC-DC single channelsolution to quickly rinse the chip channel, then use deionized water to rinse the residual acid or alkali solution, and finally, use a gas (air/oxygen/nitrogen/argon, etc.) to flush the chip channel of liquid to dry.
Typically, the cleaning sequence of different liquids will leave faint residual traces on the surface of the chip channel, because different liquids will chemically react or different liquids have different densities and viscosities, and cross-rinsing will leave some liquids behind. residual traces. If you are concerned about these residual traces, you can first rinse the chip channel with the reagent used in the experiment, then use deionized water or rinse the chip channel, and finally use ethanol or isopropanol (IPA) solution to rinse the chip channel. If there is an IPA solution, it is best to use IPA to rinse the chip channel last, because IPA is more volatile and will not leave liquid traces on the surface of the chip channel.
Typically, the cleaning sequence of different liquids will leave faint residual traces on the surface of the chip channel, because different liquids will chemically react or different liquids have different densities and viscosities, and cross-rinsing will leave some liquids behind. residual traces. If you are concerned about these residual traces, you can first rinse the chip channel with the reagent used in the experiment, then use deionized water or rinse the chip channel, and finally use ethanol or isopropanol (IPA) solution to rinse the chip channel. If there is an IPA solution, it is best to use IPA to rinse the chip channel last, because IPA is more volatile and will not leave liquid traces on the surface of the chip channel.
The definition of temperature-compensated crystal oscillator
2022年10月17日
The definition of temperature-compensated crystal oscillator is to reversely change the original physical characteristics of the piezoelectric quartz crystal (the frequency changes in a cubic curve with temperature under the piezoelectric effect) through the peripheral circuit to make the change of the original frequency of the quartz crystal with temperature as small as possible. A quartz crystal oscillator made by a compensation method.
With so many crystal oscillators on the market, why can temperature-compensated crystal oscillators survive in the era of high precision?
The development trend of temperature compensated crystal oscillator:
Accuracy, low power consumption, SPI module and miniaturization are the main research topics of temperature-compensated crystal oscillators.
In the aspect of miniaturization and chip type, there are many difficulties, among which there are two main points: one is that miniaturization will make the frequency variable range of the quartz crystal oscillator smaller, and temperature compensation will be more difficult; In the connection operation, since the welding temperature is much higher than the maximum allowable temperature of the temperature-compensated crystal oscillator, the frequency of the crystal oscillator will change. 10-6 or less. However, the improvement of the technical level of the temperature compensated crystal oscillator has not reached the limit, and the innovative content and potential are still large.
Why is the temperature-compensated crystal oscillator an important role in the era of micro-high precision?
In wireless transmission applications, SOC module the wireless transparent transmission module takes small size, low power consumption, and low delay as important development indicators. The precision of the crystal oscillator is higher, by comparing the ordinary
With so many crystal oscillators on the market, why can temperature-compensated crystal oscillators survive in the era of high precision?
The development trend of temperature compensated crystal oscillator:
Accuracy, low power consumption, SPI module and miniaturization are the main research topics of temperature-compensated crystal oscillators.
In the aspect of miniaturization and chip type, there are many difficulties, among which there are two main points: one is that miniaturization will make the frequency variable range of the quartz crystal oscillator smaller, and temperature compensation will be more difficult; In the connection operation, since the welding temperature is much higher than the maximum allowable temperature of the temperature-compensated crystal oscillator, the frequency of the crystal oscillator will change. 10-6 or less. However, the improvement of the technical level of the temperature compensated crystal oscillator has not reached the limit, and the innovative content and potential are still large.
Why is the temperature-compensated crystal oscillator an important role in the era of micro-high precision?
In wireless transmission applications, SOC module the wireless transparent transmission module takes small size, low power consumption, and low delay as important development indicators. The precision of the crystal oscillator is higher, by comparing the ordinary
タグ ：Serial server
What are the advantages and characteristics of ZigBee
2022年10月10日
IoT application of zigbee Mesh networking
First of all, the ZigBee module is based on the IEEE802.15.4 protocol technical standard. It has its own unique characteristics with the IEEE802.11 standard protocol of the WIFI module and the IEEE802.15.1 protocol standard of the Bluetooth module. WiFi Wireless Module The relationship between them is only complementary and cannot be replaced by each other. .
In the above IEEE technical standards, the physical characteristics of IEEE802.15.4 and IEEE802.11 are similar, and the CSMA/CA communication method based on CCA carrier sense is adopted, which is very suitable for many-to-many communication of devices. Mesh network has extremely high communication efficiency.
However, IEEE802.15.1 adopts the HFSS frequency hopping principle, and it is not easy to achieve similar channel detection functions. It can only work according to the time slot of the master-slave model. In the BLE Mesh application, it communicates by broadcasting, and in the BLE Mesh application It will try to avoid the situation where multiple devices communicate with the same device at the same time. Therefore, in the application of Mesh network, the compatibility and reliability of ZigBee is far better than that of BLE Mesh.
The disadvantage of ZigBee wireless technology is that the control terminal cannot be integrated on the smart phone and needs to be controlled through a gateway. Of course, there is also a ZigBee Dongle or ZigBee remote control as the control terminal, but it must also be authorized by the gateway. Unlike the BLE Mesh ad hoc network, which is a "public toilet" type of access that "comes and leaves when you want to", in short, it is BLE Mesh. Access is more convenient but ZigBee access is more secure.
Zigbee networking mode
Interoperability of zigbee technology
The ZigBee protocol has developed a set of equipment control standards since its birth, called ZCL (ZigBee Cluster Library). In the early version of the ZigBee protocol, ZCL was very imperfect and was abandoned by smart home manufacturers and other application solution providers that started earlier. As a result, the products of different equipment manufacturers are incompatible with each other, and even these products are deliberately designed to be incompatible with each other from the beginning.
However, with the introduction of the ZigBee 3.0 protocol, ZCL is a mandatory option, and chip manufacturers are also forcing the use of ZCL in chips, resulting in equipment manufacturers needing to spend additional research and development costs to make their products incompatible with other manufacturers, which leads to many equipment manufacturers. For the sake of convenience, they are forced to make their own products interconnected with other people's products.
In addition, ZCL also derived a concept called "object model", which has been borrowed by many intelligent cloud service providers, and based on this, it has also derived a concept that can be used for IPv6 (including Google Thread, which is also based on IEEE802.15.4). Matter Protocol. The object model turns the dull and cold string of data in the communication protocol into a more visual device entity, such as how many switches and several lights are mounted on this device, which sensors are mounted? How much temperature, how much brightness, is there an alarm? For device-side developers, when adding a certain function or increasing the number of certain functions to the device, they do not need to consider the compatibility of the communication protocol. copy and paste.
Compared with other mainstream IoT wireless transmission protocols, currently only BLE Mesh has launched a SIG Mesh standard, but this standard is mandatory in BLE chips, and many manufacturers can choose not to support it, resulting in BLE Mesh devices with data access. But there is a "chicken and duck talk" between equipment and equipment. Fortunately, smartphones support BLE Mesh access, allowing smartphones to act as controllers, one manufacturer and one APP, which also speeds up the scrapping and elimination of smartphones.
First of all, the ZigBee module is based on the IEEE802.15.4 protocol technical standard. It has its own unique characteristics with the IEEE802.11 standard protocol of the WIFI module and the IEEE802.15.1 protocol standard of the Bluetooth module. WiFi Wireless Module The relationship between them is only complementary and cannot be replaced by each other. .
In the above IEEE technical standards, the physical characteristics of IEEE802.15.4 and IEEE802.11 are similar, and the CSMA/CA communication method based on CCA carrier sense is adopted, which is very suitable for many-to-many communication of devices. Mesh network has extremely high communication efficiency.
However, IEEE802.15.1 adopts the HFSS frequency hopping principle, and it is not easy to achieve similar channel detection functions. It can only work according to the time slot of the master-slave model. In the BLE Mesh application, it communicates by broadcasting, and in the BLE Mesh application It will try to avoid the situation where multiple devices communicate with the same device at the same time. Therefore, in the application of Mesh network, the compatibility and reliability of ZigBee is far better than that of BLE Mesh.
The disadvantage of ZigBee wireless technology is that the control terminal cannot be integrated on the smart phone and needs to be controlled through a gateway. Of course, there is also a ZigBee Dongle or ZigBee remote control as the control terminal, but it must also be authorized by the gateway. Unlike the BLE Mesh ad hoc network, which is a "public toilet" type of access that "comes and leaves when you want to", in short, it is BLE Mesh. Access is more convenient but ZigBee access is more secure.
Zigbee networking mode
Interoperability of zigbee technology
The ZigBee protocol has developed a set of equipment control standards since its birth, called ZCL (ZigBee Cluster Library). In the early version of the ZigBee protocol, ZCL was very imperfect and was abandoned by smart home manufacturers and other application solution providers that started earlier. As a result, the products of different equipment manufacturers are incompatible with each other, and even these products are deliberately designed to be incompatible with each other from the beginning.
However, with the introduction of the ZigBee 3.0 protocol, ZCL is a mandatory option, and chip manufacturers are also forcing the use of ZCL in chips, resulting in equipment manufacturers needing to spend additional research and development costs to make their products incompatible with other manufacturers, which leads to many equipment manufacturers. For the sake of convenience, they are forced to make their own products interconnected with other people's products.
In addition, ZCL also derived a concept called "object model", which has been borrowed by many intelligent cloud service providers, and based on this, it has also derived a concept that can be used for IPv6 (including Google Thread, which is also based on IEEE802.15.4). Matter Protocol. The object model turns the dull and cold string of data in the communication protocol into a more visual device entity, such as how many switches and several lights are mounted on this device, which sensors are mounted? How much temperature, how much brightness, is there an alarm? For device-side developers, when adding a certain function or increasing the number of certain functions to the device, they do not need to consider the compatibility of the communication protocol. copy and paste.
Compared with other mainstream IoT wireless transmission protocols, currently only BLE Mesh has launched a SIG Mesh standard, but this standard is mandatory in BLE chips, and many manufacturers can choose not to support it, resulting in BLE Mesh devices with data access. But there is a "chicken and duck talk" between equipment and equipment. Fortunately, smartphones support BLE Mesh access, allowing smartphones to act as controllers, one manufacturer and one APP, which also speeds up the scrapping and elimination of smartphones.
