Hardware design of the hottest patrol controller s

2022-09-22
  • Detail

The patrol controller is mainly composed of front-end conditioning circuit, a/D conversion circuit, buffer amplification circuit, can communication circuit and optocoupler isolation circuit. As shown in Figure 2, the front-end conditioning circuit completes the collection and conditioning of battery voltage. This circuit completes the collection and matching of voltage signals and converts them into signals that can be accepted by a/D chips. The A/D conversion circuit converts the collected voltage signals into digital signals that can be processed by C8051F040 chip. The optocoupler isolation circuit completes the electrical isolation of the signal. The buffer amplifier circuit amplifies the driving signal to control the relay to connect or cut off a battery. C805 1f040 main control chip completes data processing and system control, which is the core of the whole controller. Can communication electromechanical equipment is essentially realized in the same way. Can communication between lower computer and upper computer. The indicator circuit includes the power indicator (3). Use a suitable wrench to connect each oil pipe, operation indicator and communication indicator, so that the on-site personnel can understand the operation status of the system

1 front end conditioning circuit design

the input voltage of the front end conditioning circuit is the voltage at both ends of the battery. The differential proportional operational amplifier circuit is used to collect the battery voltage. The voltage at the input of the operational amplifier shall not exceed the reference voltage through the voltage division of the front-end resistor. The output end of the operational amplifier is connected with a resistance of 100 Q and a capacitance of 0.0 L Port f respectively for current limiting and decoupling

2 use of analog-to-digital converter (ADO) and its interface design

the analog-to-digital converter of this system adopts the high-speed serial conversion chip TLC2543 of T engineering company. The conversion time is 10 ports s, and the conversion result has a length of 12, which has high enough accuracy for the voltage range of this system. There are ll analog input channels, and only four lines are needed to connect with the single chip microcomputer, including address line DIN, data line do port T, and clock line C. China is by far the world's largest mechanical equipment market LK and chip selection line CS. Ain0 ~ ainio are the inputs of 11 analog signals; CS is the chip selection end; Data worker n is the serial data input terminal, which is used to select the next analog signal to be converted; Data O port t is the converted 12, which is the serial data output end; EOC is the conversion end bit. If the timing is well controlled, you can choose not to connect; L0 clock is the input/output clock end, which is used to control the serial input and output of data; Ref+ and ref are respectively at the negative reference voltage end, which is used to set the reference voltage of analog-to-digital conversion. The system needs to collect the voltage of 20 batteries, so two tlc2543cs are used, among which CS, data n and 10 clock are common, and the data O port t of the data output terminal is independent. The stop reference voltage ref+ of TLC2543 is 2.5V, the negative reference voltage ref 1 is 0V, and the accuracy of converted data is L2

3 can bus communication circuit

c8051f040 MCU has a can controller integrated inside, but it is only a protocol controller and cannot provide physical layer drive, so it is necessary to add a CAN bus transceiver when using it. The CAN bus transceiver used here is the PCA82C250 transceiver of phi l IPS company. The PCA82C250 transceiver provides differential sending capability for the bus and differential receiving capability for the CAN protocol controller. As shown in Figure 3, 2017, the C80 51f040 microcontroller is connected with the data receiving and transmitting port of the pca28c250 transceiver after being isolated by the ANTX and canrx pins through the optocoupler, so as to realize the interface convenience of the can communication function

the internally integrated can protocol controller is controlled by the CP port through software to receive and send relevant message data and corresponding data processing in combination with PCA82C250. The can transceiver PCA82C250 fully conforms to the is01 1898 standard. It has high-speed (up to 1MB/s) anti instantaneous t-interference and the ability to protect the bus. RF t-interference (RFI) can be reduced by using slope control. The differential receiver used in the chip has the functions of resisting common mode t-interference and electromagnetic t-interference (EMI) in a wide range, as well as overheating protection and short-circuit protection against battery and ground. The chip has a low current standby mode, so that the node that is not powered on will not have any impact on the bus. It is a commonly used transceiver in the market, and its performance can fully meet the requirements of the system

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