Comparing Ublox NEO 6M and NEO M8 GPS Receivers Comparing GPS Receivers: Ublox NEO M8 vs NEO 6M In a recent video, we discussed precise altitude measurements and promised a test of GPS receivers. In this article, we will compare the newest Ublox GPS receiver, the NEO M8, with its predecessor, the NEO 6M. Methodology We compared the two sensors in one position to obtain exact relative data. This is sufficient for our purpose, as we need precise altitude measurements. The actual GPS sensors have a lot of possible configurations, but we used the pedestrian profile proposed by the manufacturer, which fits best for our bicycle power meter. Software and Configuration The manufacturer provides a free software called U-Center to work with the modules. This software can be used to change the configuration as well as read the results of the modules. We put the download link in the comments section. To use the modules together with this program, we connected our GPS module to a serial to USB converter and plugged this converter into our PC. Keep in mind that the modules are 3.3V, so we used serial to USB converters which can be changed from 5V to 3.3V. Horizontal Precision Test We measured the horizontal precision of both modules, although this is not needed for our purpose. The conditions were not optimal, as the sensor was placed near a house, and satellites in one direction were not visible to the sensor. Both sensors were placed exactly at the same place, and the conditions were exactly the same. The only difference was the time we did the two tests, one after the other. The NEO 6 module had a startup with six satellites to calculate its position, all belonging to the American system. Every second, the position was measured and put into the drawing. The result after a few minutes showed deviations in the range of 8 meters, with most measurements in the 6-meter range. The NEO M8 module had a similar performance, but with slightly better accuracy. Altitude Measurement Test We used the manufacturer's software to measure altitude and transfer it directly to an Excel sheet. The results showed that the relative precision of the altitude measurement is factors worse than the precision of a pressure sensor. Compatibility Issue with Tiny GPS Plus Library We discovered a major problem with the NEO M8 module, which does not work at all with the well-known tiny GPS Plus library. After some investigations, we found that two strings sent by the NEO M8 are slightly different to the strings sent by the NEO 6 modules. Fortunately, the solution is not very complicated. We added a few items in two areas of the tiny GPS Plus library and the whole thing works again. The changed library can be found in the comments section. Conclusion In conclusion, our test showed that the NEO M8 and NEO 6M do not deliver very different position accuracy. The precision depends more on the constellation of the satellites. However, the relative precision of the altitude measurement is factors worse than the precision of a pressure sensor. Therefore, we will use a pressure sensor to measure the altitude component in our bicycle power meter. GPS Comparison A GPS comparison is an evaluation of different Global Positioning System (GPS) devices, software, or technologies to determine their accuracy, reliability, and performance. The primary goal of a GPS comparison is to identify the strengths and weaknesses of each system, enabling users to make informed decisions when selecting a GPS solution for their specific needs. Background The development of GPS technology began in the 1970s, and since then, numerous GPS systems have been created to cater to various industries and applications. With the increasing demand for location-based services, GPS comparisons have become essential to assess the capabilities and limitations of different GPS systems. Types of GPS Comparisons There are several types of GPS comparisons, including: Device-based comparisons: Evaluating the performance of different GPS devices, such as handheld units, vehicle trackers, or wearable devices. Software-based comparisons: Comparing the features and functionality of various GPS software applications, including mapping tools and navigation systems. Technology-based comparisons: Assessing the strengths and weaknesses of different GPS technologies, such as satellite-based systems, cellular network-based systems, or hybrid systems. Introduction The u-blox NEO series is a popular choice among GPS enthusiasts and professionals alike, offering high-performance GPS receivers with advanced features. In this article, we will compare the u-blox NEO 6M and NEO M8 GPS receivers, highlighting their differences and similarities. Overview of u-blox NEO 6M The u-blox NEO 6M is a high-performance GPS receiver that supports GPS, GLONASS, and SBAS. It features a 50-channel engine and provides accurate positioning with an accuracy of up to 1-2 meters. Supports GPS, GLONASS, and SBAS 50-channel engine Accuracy: up to 1-2 meters Overview of u-blox NEO M8 The u-blox NEO M8 is a high-performance GPS receiver that supports GPS, GLONASS, Galileo, BeiDou, and SBAS. It features a 72-channel engine and provides accurate positioning with an accuracy of up to 1-2 meters. Supports GPS, GLONASS, Galileo, BeiDou, and SBAS 72-channel engine Accuracy: up to 1-2 meters Comparison of Key Features Feature NEO 6M NEO M8 Number of Channels 50 72 Supported Constellations GPS, GLONASS, SBAS GPS, GLONASS, Galileo, BeiDou, SBAS Accuracy up to 1-2 meters up to 1-2 meters Power Consumption 30mA (typical) 25mA (typical) Conclusion The u-blox NEO 6M and NEO M8 GPS receivers are both high-performance devices with advanced features. The main difference between the two is the number of channels and supported constellations. The NEO M8 has a higher number of channels and supports more constellations, making it a better choice for applications that require high accuracy and reliability. Q1: What is the main difference between Ublox NEO 6M and NEO M8 GPS Receivers? The main difference is that NEO M8 supports GLONASS, Galileo, and SBAS, in addition to GPS, while NEO 6M only supports GPS. Q2: Which receiver has better sensitivity? The NEO M8 has better sensitivity due to its support for multiple constellations and signal processing improvements. Q3: What is the power consumption of each module? The NEO 6M typically consumes around 40mA, while the NEO M8 consumes around 50-60mA due to its more complex processing and additional features. Q4: Do both modules support WAAS/EGNOS/MSAS? Yes, both the NEO 6M and NEO M8 support WAAS/EGNOS/MSAS, which are satellite-based augmentation systems. Q5: Can I use the same firmware for both modules? No, the firmware is not compatible between the two modules due to differences in hardware and features. Q6: What is the update rate of each module? The NEO 6M has a maximum update rate of 10Hz, while the NEO M8 can achieve an update rate of up to 20Hz. Q7: Are there any differences in the interfaces supported by each module? Yes, the NEO M8 supports a wider range of interfaces, including UART, SPI, I2C, and USB, while the NEO 6M only supports UART and I2C. Q8: How do the two modules differ in terms of accuracy? The NEO M8 typically achieves better accuracy due to its support for multiple constellations, signal processing improvements, and advanced algorithms. Q9: Can I upgrade from a NEO 6M to a NEO M8? Yes, but it requires significant changes to the system design and firmware, as well as a possible hardware upgrade. Q10: Are there any differences in the operating temperature range of each module? The NEO M8 has a slightly wider operating temperature range (-40°C to 85°C) compared to the NEO 6M (-30°C to 80°C). Pioneers/Companies Description 1. u-blox Developed the NEO-6M and NEO-M8 GPS receivers, known for their high-performance and low-power consumption. 2. Garmin A leading manufacturer of GPS navigation systems, utilizing u-blox's GPS receivers in some of their products. 3. Trimble A company specializing in GPS and GNSS solutions, offering high-precision receivers for various industries. 4. Navico A leading provider of marine electronics, using u-blox's GPS receivers in some of their navigation systems. 5. DeLorme A company offering GPS mapping and satellite communication solutions, utilizing u-blox's GPS technology. 6. Hemisphere GNSS A leading provider of high-performance GNSS receivers, offering products for various industries such as surveying and agriculture. 7. Septentrio A company specializing in GNSS solutions for demanding applications such as surveying, mapping, and precision agriculture. 8. Topcon Positioning Systems A leading provider of precision positioning systems, offering high-performance GPS receivers for various industries. 9. JAVAD GNSS A company specializing in high-precision GNSS receivers and antennas, serving various industries such as surveying and mapping. 10. NovAtel A leading provider of high-performance GPS and GNSS solutions, offering products for various industries such as aviation and maritime. Feature Ublox NEO-6M Ublox NEO-M8 GNSS Constellation Support GPS, WAAS, EGNOS, MSAS GPS, GLONASS, Galileo, BeiDou, QZSS, SBAS (WAAS, EGNOS, MSAS) Number of Channels 50 channels 72 channels Position Accuracy (CEP) 2.5 meters (GPS only), 1.8 meters (with SBAS) 1.5 meters (GPS, GLONASS, and Galileo), 1 meter (with RTK) Velocity Accuracy 0.2 m/s 0.05 m/s Time-to-First-Fix (TTFF) 30 seconds (hot start), 45 seconds (warm start), 60 seconds (cold start) 25 seconds (hot start), 35 seconds (warm start), 50 seconds (cold start) Sensitivity -160 dBm -167 dBm Power Consumption 50 mA (typical), 100 mA (max) 45 mA (typical), 90 mA (max) Interface Options UART, SPI, I2C, USB UART, SPI, I2C, USB, CAN Dimensions (mm) 16 x 12.2 x 2.4 15.5 x 11.6 x 2.3 Operating Temperature Range -40°C to +85°C -40°C to +85°C Storage Temperature Range -50°C to +150°C -50°C to +150°C