As reported from their website, seems like a great upgrade for the telemetry radio, maybe to also carry RC control, and depending on bandwidth maybe using it also for a digital video feed.
It is on indiegogo
https://www.indiegogo.com/projects/xrange-extreme-long-range-wireless-module-for-868-915-mhz
As listed on their site:
XRange: Extreme Long Range Wireless Module based on sx1272 LoRa transceiver for 868 or 915 Mhz (will be available in Q4 2014)
What is XRange?
It is a wireless electronics development platform that provides extreme long range spread spectrum communication and has over 12km (7 miles) of usable range.
XRange is based on the SX1272 LoRa™ long range modem, low-power ARM micro-controller and powerful switching power supply.
What can you do with XRange?
- Connections in warehouses where data cables and other wiring is difficult or impractical.
- Lighting, temperature and other building controls.
- Battery-powered data loggers, weather stations, and data logger/controllers.
- Solar panels management and monitoring.
- Data communication for the Internet of Things.
- Remote controlled irrigation systems.
- Point-of-sale systems.
- Security applications.
Why You should choose the XRange?
- It has extreme long range.
- It has ability to communicated through walls and other obstructions.
- It is low power.
- It is low cost.
- You can implement many wireless projects with little effort.
Features
SX1272 LoRa™ long range modem
- 157 dB maximum link budget
- +20 dBm at 100 mW constant RF output
- +14 dBm high efficiency PA
- Programmable bit rate up to 300 kbps
- High sensitivity: down to -137 dBm
- Low RX current of 10 mA, 100 nA register retention
- Fully integrated synthesizer with a resolution of 61 Hz
- FSK, GFSK, MSK, GMSK, LoRaTM and OOK modulation
- Packet engine up to 256 bytes with CRC
For more information about sx1272
Low-power STM32L152 microcontroller
- ARM Cortex-M3 CPU at 32MHz
- 256 KBytes Flash
- 2x Op-Amp
- 12bit ADC 1 Msps 2 channels
- 12bit DAC 2 channels
- 2x Comparators
- USB 2.0 Full Speed
- Up to 2x USARTs, 2x SPIs 16Mbit/s, 2x I2C
- Up to 11x timers
- 96bit unique ID
- Real-time clock
For more information about STM32L152
Board Power supply (Based on TPS62160)
- through USB bus
- external input voltage 3.3V – 17V
- system voltage 3.3 or 2.7 selectable
- output 3.3V/1A or 2.7V/1A selectable
- output 5V from USB port
I/O Pins
- Over-current protection on all I/O pins
- ESD protection on USB port
MCU Flash Programming
- USB Bootloader
- SWD connector
Dimensions 78 mm x 42 mm
Pins Description
Range Test
Software development.
We are working to provide open source libraries and firmware.
Mbed
“The mbed development platform is the fastest way to create products based on ARM microcontrollers.”
We are working to provide libraries and firmware based on Mbed platform.
Mbed already provides driver for sx1272.
Keil MDKWe have developed libraries and firmware based on Keil MDK platform.
Comments
Spectrum is limited and very high value. Getting new spectrum for hobby use is a difficult proposition and commercial use means an expensive license. Analog video transmission is an inefficient use of spectrum, requiring a bandwidth of 8 MHz or more. A lot of voice or data channels could fit in 8 MHz... The hobby would need several channels to allow multiple simultaneous users which translated to a very high value segment of spectrum.
Highly compressed digital video opens the possibility for much more efficient spectrum use and fewer problems with multiple users. It is not without problems but it is more than proven. The problem for hobby FPV is that there isn't a small and low cast combination of digital video source and suitable transmitter.
Most of the existing video transmitters used by the hobby transmit of amateur (HAM for the Americans in the audience) radio bands where there is an allocation for amateur TV, at least is many parts of the world. In some areas there are exemptions for lower power transmission without an amateur radio license but that is typically 25mW or less and it ignores the fact that the licensed users can transmit 120W and have no idea that someone has just lost their FPV video link. A licensed user has the right to operate without interference from unlicensed users but an unlicensed user does not. There really are still amateurs transmitting video and doing so at high power for long range links and through repeaters which can cover a very large area.
Full disclosure: I have an advanced amateur radio license (the top level available here), making my video transmission perfectly legal. That does no mean I ignore the larger problem and have no interest in a fix. I still risk being wiped out by other FPV users or high power transmitters and we are all stuck with the problem of limited channels when we want to fly with others.
Don't forget the elephant in the room. The WRC has not yet allocated new RPAS spectrum. This is coming and has been on the cards for years. Look at the Phantom Vision, currently not permitted for commercial use in the UK because of its use of 5.8 for control and 2.4 to send video to the phone or tablet.
More radio options is always a good thing to have. As there are extremely long range telemetry radios available now (RFD900 and others), it would be good to get something with more bandwidth for FPV.
I have nearly bought the JDrones diversity radio (http://store.jdrones.com/RDF900_Telemetry_Modem_p/rdf900mdm1.htm) several times. The often quote ranges of 25km+, 40km or 60km, at one point, are far more than would ever be needed and 1W is overkill but it would be great on a ground station for a very reliable telemetry link.
An digital video transmitter with frequency hoping would give a much more reliable FPV link and has potential advantages for legal video transmission. In Australia, most people transmitting FPV video without an amateur radio license are doing so illegally because they exceed the 25mW limit for 5.8GHz. Much higher power limits are available for reduced bandwidth, frequency hopping transmission, on a few bands.
I've messed around with FPV digital video, using a Raspberry Pi over wifi, and the delay can be down to 100ms which is no worse than using a Mobius for FPV. Not really a practical solution due to the weight and likelihood that a wifi link would be unreliable in most cases.
There was a great post here last year using RPi with another 900 MHz radio link for FPV that shows this isn't impossible but we are still short of a entirely practical solution.
http://diydrones.com/profiles/blogs/fpv-setup-with-raspberry-pi
Tearig,
We are building a test transceiver around the SX1272 as a possible replacement for the AT86RF212 (not compatible, of course) with matching for the US ISM 900mhz band only. I'll let you know what our field test results are (our application operates at ground level only so our ranges will likely be significantly shorter due to ground clutter and fresnel losses).
You might want to use a simple matching network and just assembly the board with different values for the matching network parts for the different bands. I am not sure many users have a legitimate use for operation in multiple bands.
Dean, I agree with all of your points, I had posted this video before on the idea for the flight control and fpv from the telemetry data, using high data connection on the ground and existing imagery, this then would be augmented in a number of ways.
The post indiegogo includes a 2.4 ghz option also, we are looking at still using multiple Frqs, just trying to eliminate some of the inefficient parts by having in most cases 3 bands, working on this from both sides we are working on a openFPV project and trying to encode the telemetry in the video while also use the telemetry to simulate the environment. I felt using this type of hybrid system and the most likely high speed data and extra cpu processing power on the ground would be the advantage.
The video below is just my mock up to explain the concept, manually synced
The LoRa system does provide really good receiver sensitivity if you use a high spreading factor. The catch is that increasing the spreading factor also increases the data latency to a point where it may not be acceptable for real-time flight control. Telemetry and auto-pilot control would be fine.
According to the SemTech documentation, with a high spreading factor, the LoRa modem can operate at 20 db below the noise floor, so it might be a lot more useful in a noisy environment than other radios.
The SemTech chip tops out at 300kbps so you are not going to able to transmit useful video using one of these, nor can it be modified for higher data rates. The LoRa encoding scheme might be able to be used with an SDR to get up to video rates but I haven't found must real information on how the scheme works and even with full docs it would probably be a huge project to implement the SDR.
The RDF900 looks good, are you using it now?
my hesitation is the 800 mah draw at power. Having used a 1 watt system for Video tx it does have the problem of robbing allot of power and reducing flight times. Thinking adding another would further reduce the loft time..
If the system described works on the lower power band my hope is to implement something similar for the video tx also...
As you say too much sensitivity is not an advantage in a noisy band (Gsm in Europe)
@Hugues
Look at the receiver sensitivity. There is no need to have 1W if you have a very low sensitivity
The problem is what SNR you need for a given BER and the noise floor in your area
This is very similar to the HopeRF RFM9X modules. You can get boards today based on those module:
http://www.anarduino.com/miniwireless/
Also, you're not going to get the very long range with higher bandwidths. The longer range requires using LoRa mode, and that's only in the few kbps range.
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