Drones
The most important characteristic for drones is their weight.
Weight: 6.2 grams
For the lightest drones, weight is the most crucial factor. If you take the ELT0150 board weighing 4 grams and the ELT0176 antenna weighing 2.2 grams, you will get an ultra-light and affordable solution weighing 6.2 grams with very low power consumption due to the use of the MAX-M10S receiver. The reception quality of this antenna can be improved with a homemade ground plane. The board uses a 6-pin JST SH connector and has I2C and UART interfaces at TTL levels. To receive Beidou signals, you need to switch the receiver to the B1C signal instead of B1I.
Weight: 7.5 grams
The most suitable board is the ELT0169 with the SAM-M10Q receiver. The board interfaces include I2C and UART at TTL levels, and it weighs 7.5 grams with a 6-pin JST SH connector. There is an alternative board of similar weight, the ELT0020 with the MAX-M8Q receiver, but they have almost three times higher power consumption and cannot receive Beidou signals. Additionally, the ELT0020 does not support I2C and is significantly more expensive. The advantage of this option is its very low weight, but the drawback is the poor solution quality due to the use of a small patch antenna without a ground plane.
Weight: 14 grams, Pixhawk
For the Pixhawk autopilot, a board with a magnetic compass is required. The lightest board with the LIS3MSL magnetic compass is the ELT0102 with the M9N receiver, weighing 14 grams. It has a mini USB connector and 6 contacts with a UART interface for the receiver and an I2C interface for the LIS3MSL compass. The advantage is its low weight, but the drawback is its very small groundplane, which affects reception quality.
The ELT0099 board is a slightly improved version of the ELT0102, weighing 29 grams. It has the same connectors and interfaces, but both the antenna and ground plane are larger, resulting in better reception quality. The ELT0024 board weighing 16 grams, with the MAX-M8Q receiver, is chosen mainly for its small size (25x25 mm), but it does not have a mini USB connector. Due to its minimal size, it has worse reception than the 14-gram ELT0102, and due to the outdated receiver, it can receive only 3 satellite systems simultaneously, while the M9N can receive all 4 major satellite systems simultaneously. Unfortunately, there are no similar boards for M9V and M10S receivers.
Weight 18 grams
For heavier drones, there is a lightweight Helix antenna ELT0124 for L1 frequency weighing 11 grams. This antenna screws onto an SMA connector and is held solely on the connector, so it is only suitable for boards with this connector (see section "Boards with SMA Connector") assembled on single-frequency receivers. The most optimal receiver is the NEO-M9V. The advantage of this receiver is a solution rate of up to 50 times per second and the ability to obtain coordinates with some accuracy without satellite reception, for example, when flying under bridges, due to UDR technology. The best board for M9V is the ELT0165 (weight: 6.8 grams) with 12 contacts and interfaces such as UART, I2C, SPI, and USB. Slightly heavier is the ELT0173 board weighing 9 grams, with a mini USB connector and 6 contacts with I2C and UART. The second option is the MAX-M10S receiver. The advantage of this receiver is low power consumption. The ELT0151 board weighs 7 grams and has a JST SH connector with I2C and UART interfaces.
Weight 18 grams, Ardupilot
Since Ardupilot requires SPI, the lightest set for it is the ELT0124 and ELT0165 described above. The advantages are a 50 Hz solution rate and UDR.
Weight 29 grams and RTK
The set for receiving with centimeter accuracy (RTK) at a distance of up to 50 km from the base station (see "RTK and PPP") is based on the ELT0014 (or ELT0014W) antenna for the L1/L2b range weighing 20 grams and the ZED-F9P receiver. This antenna screws onto an SMA connector and is held solely on the connector, so it is only suitable for boards with this connector (see section "Boards with SMA Connector") assembled on a dual-frequency receiver ZED-F9P. The optimal set is the ELT0091 bundle, consisting of the ELT0014 antenna and the ELT0087 board (weight: 9 grams) with mini USB and JST SH connectors on 12 contacts with interfaces such as I2C, SPI, and 2 UART. The ELT0092 board differs only in having 14 contacts instead of connectors, and the ELT0112 board is slightly heavier (11 grams) and, in addition to 14 contacts, has a mini USB connector. The best of them is the ELT0087 with an extremely low noise level stabilizer.
To improve reception, you can use a higher quality but more expensive and heavier ELT0121 antenna (ELT0121W) weighing 35 grams or a slightly more modest ELT0170 antenna weighing 32 grams. Another option is the ELT0152 corner antenna weighing 28 grams.
