Arduino Practical Application - 6MV2 Flight Control GPS Module

Experiment: GY-NEO-6MV2 New Flight Control GPS Module (with Ceramic Active Antenna)

The NEO-6M is a GPS module of superior performance, developed by ALIENTEK. Its core module employs the UBLOX NEO-6M module, possessing 50 channels, a tracking sensitivity as high as -161dBm, and a maximum output frequency for measurements of 5Hz. The NEO-6M module is equipped with a high-performance passive ceramic antenna (thereby negating the requirement for separately purchasing costly active antennas). It is compatible with both 3.3V and 5V microcontroller systems, and incorporates a built-in rechargeable backup battery (enabling warm start or hot start functionalities). With compact dimensions of 25.5mm x 31mm, the module connects externally via four pins spaced at 2.54mm intervals.

NEO-6M Module  Features:

1. u-blox 6 positioning engine:

Tracking sensitivity: -162dBm, cold start sensitivity: -148dBm

Faster acquisition speed with AssistNow Autonomous function

Configurable power management

GPS/SBAS hybrid engine (WAAS, EGNOS, MSAS)

Anti-jamming technology 

1. Easy integration with u-blox wireless modules
2. A-GPS: AssistNow Online and AssistNow Offline services compliant with OMA SUPL specifications
3. Backward compatible (hardware and firmware); easy migration from NEO-5 series or NEO-4S
4. Reliable LCC package for high cost-effectiveness\
5. Operating temperature range: -40°C to 85°C

Note 1: Cold start refers to the loss of all GPS data in the module, similar to losing both main and backup power, requiring a full restart. A warm start happens when the module has GPS history but the visible satellite data is outdated, necessitating a partial restart. A hot start occurs when the module's GPS history matches current satellite data, allowing for a quick restart.

Note 2: The current specification pertains to continuous operation mode, and power consumption can be optimized by selecting the Power Save Mode.

Note 3: When VCC exceeds 3.3V, VCCX=3.3V; otherwise, VCCX=VCC.

Note 4: The TXD and RXD pins on the module have 510 ohm resistors for compatibility. Avoid high wire resistance, particularly with USB to TTL serial modules, to prevent issues with LEDs on the pins. The NEO-6M GPS module supports various baud rates, configurable via serial settings and stored in the EEPROM, with a default of 38400 baud (8 data bits, 1 stop bit, no parity).

NEO-6M Module Key Parameters:

1. Accuracy

Positioning: 2.5m CEP

SBAS: 2.0m CEP

Cold Start Acquisition: 29s

Warm Start Acquisition: 27s

Assist Start: <3s

Hot Start: <1s

1. Sensitivity

Acquisition: -162dBm

Tracking: -147dBm

Cold Start: -146dBm

1. Multipath Suppression

Intelligent multipath detection and suppression

A-GPS

Supports AssistNow Online and AssistNow Offline

1. Operational Constraints

Velocity: 515m/s (1000 knots)

Interfaces:

1 UART interface

1 USB V2.0, full speed 12Mbit/s

1 DDC interface

1 SPI interface Serial and I/O voltage: 3V level Protocols: NMEA, UBX binary Configurable digital I/O interfaces for time pulse 1 EXTINT input interface

1. Electrical Parameters

Voltage: 2.7V – 3.6V

Power Consumption: <80mW @ 1.8V

120mW @ 3.0V Backup Supply: 1.3V - 4.8V at 30uA Antenna Types: Active and Passive Operating Temperature: -40°C to +85°C Storage Temperature: -40°C to +85°C

GPS Ceramic Active Antenna: GPS terminals use satellite signals for positioning and navigation, requiring specialized antennas due to the weak signal strength of L1 (1575.42MHz) and L2 (1228MHz) frequencies. A GPS antenna comprises a receiving antenna and a preamplifier, with the former converting satellite radio waves into usable current for electronic devices. Most built-in GPS antennas are made of right-hand circular polarized ceramic materials, including a ceramic antenna, low-noise signal module, cable, and connectors.

Principles of Operation for GPS Antennas:

1. Ceramic Element: Ceramic powder quality and sintering process affect performance. Common sizes are 25×25, 18×18, 15×15, and 12×12 mm. Larger elements have higher dielectric constants, resulting in better reception and higher resonant frequencies. Square design ensures consistent resonance in the XY direction for uniform satellite signal reception.

1. Silver Coating: The ceramic antenna's silver layer impacts its resonant frequency, ideally set at 1575.42MHz for GPS. Environmental factors can alter this frequency, particularly when the antenna is installed. Modifying the silver coating's shape is essential to restore the frequency to 1575.42MHz.

1. The feed point on the ceramic antenna gathers resonant signals for transmission to the backend. It's typically offset from the center for impedance matching, requiring minor adjustments in the XY plane. This can be done in one axis for single-pole antennas or in both axes for dual-pole antennas, providing a straightforward and economical impedance matching solution..

1. Amplifier: The PCB supports the ceramic antenna with a shape and area that optimizes GPS signal reception. A continuous ground area of 7cm×7cm maximizes antenna efficiency. Despite external constraints, efforts are made to keep the area and shape consistent. Amplifier gain should match the LNA gain; for instance, GSC3F requires total gain before signal input to be under 29dB to avoid signal oversaturation and self-excitation.

GPS antennas perform best in open outdoor areas, whereas interference or obstruction may occur within vehicles due to metal casings, glass coatings, especially those containing metallic particles, in-car audio systems, etc., which can disturb or even impede the internal GPS antenna's signal reception. Indoors, obstacles like reinforced concrete can hinder or completely block GPS signal reception.

NEO-6MV2 Flight Controller GPS Module (with Ceramic Active Antenna)

1. Model: GY-GPS6MV2
2. Universal 3V-5V power supply
3. Module equipped with ceramic active antenna for strong signal reception
4. EEPROM for retaining configuration parameter data during power loss
5. Includes data backup battery
6. Features LED signal indicator lights
7. Antenna size: 25*25mm
8. Module size: 25mm*35mm
9. Mounting hole diameter: 3mm
10. Default baud rate: 9600
11. Compatible with various flight controller modules and GPS testing software on computers

TAG: GPS Module; Electronic components; Electronics Product Development