Air-Quality Detection Module Digital Type VOC Module （Model：ZPS20） User’s Manual Version:1.2 Issue Date:2023.7.10 Zhengzhou Winsen Electronics Technology Co.

Air-Quality Detection Module Statement This manual’s copyright belongs to Zhengzhou Winsen Electronics Technology Co., LTD. Without the written permission, any part of this manual shall not be copied, translated, stored in database or retrieval system, also can’t spread through electronic, copying, record ways. Thanks for purchasing our product. In order to let customers use it better and reduce the faults caused by misuse, please read the manual carefully and operate it correctly in accordance with the instructions. If users disobey the terms or remove, disassemble, change the components inside...

Air-Quality Detection Module Digital type ZPS20 Module Profile Digital type ZPS20 module is a general-purpose air quality sensor module. This module is to detect VOC gas concentration, ambient temperature and humidity, adopting advanced semiconductor VOC gas sensor and MEMS temperature humidity sensor. It has the features of high sensitivity and digital output, which is convenient to use. Features High sensitivity; Excellent long-term stability; Long lifespan; Application Air cleaner, fresh-air system, intelligent integrated ceiling, air quality detector, ventilation fans, and air-condition etcs...

Air-Quality Detection Module PIN Definition PIN1 SCL(Serial Clock) SDA(Serial Data) Sensor Size Sensor Communication 1. Communication Mode The ZPS20 module adopts IIC communication mode, and the IIC address is 89(0x59). All module instructions consist of two bytes (16 bit), and there are no CRC bytes after the command; The data packet returned from the sensor is transmitted as a two-byte (16-bit) measurement and a one-byte (8-bit) CRC. 2. Typical IIC communication timing between the host and VOC modules In the IIC bus, the sensor as a slave device supports communication rates up to 70kHz. When...

Air-Quality Detection Module (3) The host reads the measurement result. If the communication fails, the host waits for 1s and sends the measurement command again. IIC communication timing Table 3 IIC parameter Initial signal time SCL clock high level width SCL clock low level width time set relative to the SCL edge start condition Data retention time relative to SCL SDA edge data set time relative to the SCL SDA edge Set time on SCL stop condition The bus idle time between the stop condition and the start condition 3. IIC communication command (1) Read the VOC measurement The host can periodically...

Air-Quality Detection Module (2) Read the module serial number Within 3 minutes of power-on, the host can send this command to obtain the serial number of the VOC module as actual demand. Once communicated, the serial number can be obtained, and repeat sending is not required. Table 6 IIC serial no. reading command Hexadecimal command code This command provides the serial number of the VOC module by returning 3 x 3 bytes (2 + CRC bytes). The value returned by serial no. reading command The 1st (highest) and 2nd bytes of the serial number. The 4th and 5th bytes of the serial number The 7th and...

Air-Quality Detection Module 4. Example of IIC reading data Trigger measurement data A Start Read VOC_index value A Start VOC_index high byte 5. Checksum calculation The CRC algorithm generates an 8-bit CRC checksum for each digit transmitted from behind. The CRC is the result of the check of two bytes of data that were previously transmitted. //CRC verification type: CRC8/MAXIM // Polynomial: X8+X5+X4+1 //Poly: 0011 0001 0x31 // Data-high would be 1000 1100 0x8c after transferring. //C implementation code: U8 Calc_CRC8(U8 *message, U8 Num) { U8 i; U8 byte; U8 crc = 0xFF; for(byte = 0; byte <...

Air-Quality Detection Module Recommendations for Installation It is recommended to install the module in a place that can have good contact with the ambient air, preferably in a parallel direct air flow. The direction of the air flow follows the direction shown by the green arrow in the following figure, and the direct air flow in the opposite direction and perpendicular to the sensor is prohibited. If the PCB is not placed in the air flow, it is recommended that the PCB be placed vertically and the T/H sensor be placed under the gas sensor to prevent heat convection from affecting the T/H sensor....