【正文】
s heart rate. Not overrun, through single chip microputer internal handler converts your BCD code, through CD4511 decoding through the 8 period of LED digital tube number, according to the beating of the heart and the heart count 0. Judgment have K5 button press at this moment, if you have, the end of a subroutine, return to a subroutine, if not, then continue to heart rate measurement. temperature testing flow chart Temperature detection figure as shown above, due to the MCU and DS18B20 adopts the model of single bus, so when programming in strict accordance with the read/write timing of DS18B20, the first is higher cable time around 500 microseconds, and then release the data line, and single chip microputer waiting for 60 ~ 240 microsecond pulse DS18B20, once the DS18B20 the pulse, monolithic integrated circuit receives the pulse, the issue of DS18B20 is initialized, a ROM instruction first, then a RAM instruction, instruction in temperature transformation, then delay 750 microseconds, microcontroller reads the temperature at this moment, if transfinite alarm alert doctors, if there is no overrun will temperature using digital tube display. Finally determine whether has the K5 button press if press this key, then exit the subroutine, return to the main program, if the key does not press the continue testing temperature. blood pressure test flow chart Blood 。 A5 constitute a follower, used for output signals of pressure sensor BP01 isolation buffer。 Operating temperature range: 0 ~ 70 ℃ 。 Adopts the internal calibration and temperature pensation method, so as to improve the measurement accuracy, stability and repeatability, within the scope of the full range, accuracy of plus or minus 1%, disorder of zero is not more than + 300 mu for V. The main performance parameters of BP01 Table 1 as BP01 in supply voltage Vs V TA, environment temperature is 25 ℃ when the main performance parameters BP01 limit parameter is as follows: Maximum working voltage: 20 VDC。 If 0 0 the write logic. Particular case is shown in figure 9: Figure 9 DS18B20 write sequence DS18B20 reading sequence Single bus devices only read sequence in SCM, to transmit data to the host, so, after sending the read data mand on the host, must arise immediately read sequence, so that data can be transmitted from the machine. All read timing needs at least 60 us, and in between two independent reading sequence will need at least 1 us recovery time. Each reading sequence initiated by the host at least 1 us down bus. After the host read sequence, single bus devices on the bus to send 0 or 1. If send 1 from the machine, to keep the bus for the high level。 If the temperature is less than zero, this 5 to 1, to value need to remove the 1 x to again can get the actual temperature. Such as digital output for 07 d0h + 125 ℃ , ℃ + digital output for 0191 h, ℃ for FF6FH digital output, digital output for FC90H 55 ℃ . [3] are shown in table 2: The transformation temperature in table 2 125 0000 0111 1101 0000 ℃ 07 d0h 85 ℃ , 0000, 0101, 0101, 0000, 0550 h ℃ 0000 0001 1001 0001 0001 h ℃ 0000 0000 1010 0010 00 a2h ℃ 0000 0000 0000 1000 0000 h 0 ℃ 0000 0000 0000 0000 0000 h ℃ FFFFH 1111 1111 1111 1111 ℃ FF5EH 1111 1111 0101 1111 ℃ FE6FH 1111 1110 0110 1110 And 55 ℃ FC90H 1111 1100 1001 1100 DS18B20 read/write sequence DS18B20 work agreement process is a line: initialization ROM operation instructions storage operation and data transmission. Its sequence including initialization timing, writing time sequence and read sequence, read and write it in four types: respectively is to write, write, read 1, 0, 0, 1. DS18B20 the initialization sequence All operations on 1 wire device starts in the initialization, initialization process by the host of the reset pulse and pulse response of 1 wire device. On 1 wire device reset pulse is actually the host by down the bus, host by lower bus, the bus pulled again after 480 um make all 1 wire bus reset device, 1 wire bus device after receiving the reset pulse is told through the lower bus host 1 wire device is ready. 7) as shown in figure 3: Figure 8 DS18B20 the initialization sequence DS18B20 write sequence Write sequence began in the single chip microputer to bring down the bus. Write 1 sequential way: single chip microputer in the lower after the bus, then must be released within 15 us bus, bus pull pull up resistors from 5 k to high level。 Will gather to the heart rate signal is posed of CD4069 3 gate level 3 amplifier circuit of amplification, and then by the level 2 trapezoidal filter circuit, posed of a series resistor capacitor filter processing, can obtain the human heart rate range of signal (approximately between Hz to Hz)。 Otherwise, it shows that the ongoing A/D conversion. OE as the output enable signal, is used to control the three output latch to microcontroller output data conversion. OE = 1, the output data by converting。 Under the edge, to begin A/D conversion。 Send the data, the ALE is invalid, P0 interface output data, normal operation, and because of the ALE can be issued according to 1/6 of the main vibration frequency fixed frequency, so sometimes can take advantage of. C. RST/Vpd (9 feet) : reset signal/standby power input. When the oscillator is working, if the pin to keep two cycles of high level, can make the microcontroller reset. This pin also can be used as the input end of the standby power, when the microcontrol