ZE07

Overview

ZE07-CO is a UART-based electrochemical carbon monoxide (CO) sensor. It supports two communication modes:

• Initiative Upload (IU) - sensor automatically streams 1 frame/s (default mode).
• Question and Answer (QAA) - host sends a query command, sensor replies once.

Technical Parameters

Parameter	Value
Target gas	CO
Interference gas	Alcohol and other gases
Detection range	0~500 ppm
Resolution	0.1 ppm
Output	UART (3V-TTL) / DAC (0.42V, 0full scale)
Working voltage	5V~12V (no reverse-polarity protection)
Warm-up time	≤3 min
Response time	≤60 s
Recovery time	≤60 s
Operating temperature	-10°C~55°C
Operating humidity	15%RH~90%RH (no condensation)
Working life	3-5 years (in air)

Pin Description

Pin	Function
1	Reserved
2	NC
3	Reserved
4	Reserved
5	GND
6	NC
7	UART RXD (0~3.0V, data input)
8	UART TXD (0~3.0V, data output)
9	Reserved
10	DAC output (0.4V2V, 0full scale)
11	NC
12	NC
13	NC
14	GND
15	Vin (5V~12V)

Communication Protocol

UART settings

Configuration	Value
Baudrate	9600
Data bits	8
Stop bits	1
Parity	None

UART command

All frames (commands and responses) are 9 bytes long.

Switch to QAA mode

Byte 0	Byte 1	Byte 2	Byte 3	Byte 4	Byte 5	Byte 6	Byte 7	Byte 8
0xFF	0x01	0x78	0x41	0x00	0x00	0x00	0x00	0x46

Switch to IU mode

Byte 0	Byte 1	Byte 2	Byte 3	Byte 4	Byte 5	Byte 6	Byte 7	Byte 8
0xFF	0x01	0x78	0x40	0x00	0x00	0x00	0x00	0x47

QAA query command

Host sends this frame to request one reading while in QAA mode:

Byte 0	Byte 1	Byte 2	Byte 3	Byte 4	Byte 5	Byte 6	Byte 7	Byte 8
0xFF	0x01	0x86	0x00	0x00	0x00	0x00	0x00	0x79

Response frame

IU mode (auto-streamed, 1 frame/s)

Byte	Meaning
0	Start byte (0xFF)
1	Gas type (0x04 = CO)
2	Unit (0x03 = ppm)
3	No. of decimal places
4	Concentration high byte
5	Concentration low byte
6	Full range high byte
7	Full range low byte
8	Checksum

Concentration (ppm) = (byte[4] << 8 | byte[5]) * 0.1

QAA mode (response to query command)

Byte	Meaning
0	Start byte (0xFF)
1	Echoed command byte (0x86)
2	Concentration high byte
3	Concentration low byte
4-7	Reserved / full-range data
8	Checksum

Concentration (ppm) = (byte[2] << 8 | byte[3]) * 0.1

Checksum

Two's-complement sum over bytes 1 to 7:

checksum = ~(byte[1] + byte[2] + ... + byte[7]) + 1

Byte 8 of every frame (command or response) must equal this value.

Cautions

• DO NOT insert or extract the sensor on the PCB board.
• DO NOT change or move the electronic part on the module.
• Avoid sensor contact with organic solvent, coatings, medicine, oil and high concentration gases.
• Excessive impact or vibration should be avoided.
• Please keep the modules warming up for at least 5 minutes when first using.
• Please do not use the modules in systems which related to human being’s safety.
• Please do not use the modules in strong air convection environment.
• Please do not expose the modules in high concentration organic gas for a long time.