As you know, we are working on OpenLRS project since few years and It is an Open Source RC control system with telemetry, I2C and others. Few days before i designed this new boards. It is based on OpenLRS system but there is no 3.3v regulator, PPM or Servo outputs. It is an open Source Telemetry Module with XBee footprint. And today prototype boards arrived and i populated it for test and passed. Now we are waiting for quality PCB production (15 days).
- No more buffering problem of Xbee modules. Real time telemetry or control is possible.(10ms latency)
- Longer Range, lower frequency
- No networking stack. Everything in the code. You can write a mesh or point to point, everything is possible.
- Arduino ProMini based boot and Open Source design
- No Programmers or FTDI cable require. Just put it to USB to XBee adapter and load the firmware over Arduino.
- XBee footprint. (Serial pins only)
- 100mW 400-470mhz RF Module with FHSS and other functions (RFM22B)
- up to 3 miles range. (The record is 12KM with Nagoya antenna in England)
- 3.3v design.
My Job List:
- Open google code page for OpenBee in a few days (http://code.google.com/p/openbee/)
- Isolate the OpenLRS code's telemetry part.
- Test it at the field.
- Add an option for MAVLink packages (need help!!!)
- Find project members.
- Add the code for simulating OpenLRS Transmitter modules. Computer based RC control is possible with OpenLRS Receivers. Joysticks or something like that.
What are you thinking about OpenBee project? Is it good or bad idea?
Thanks for your comments
@Melih, Sorry for animating this thread, but I stumbled upon it looking for something exactly like your HM-TRP on XBee board from the September 18, 2012 at 1:51pm post. Not sure if you still have any of those boards, or some related info. Thanks.
Sorry guys i just back from a long project, and more details ready(please check the diydrones main page)
@Jesper, It is fully compatible with OpenLRS firmwares and system. OpenBee based on OpenLRS Rx V2 boards ;) telemetry receiver or, "fly with joystick" options coming soon ;)
@Martin, Can you share the requirements for certification? HopeRF is a big company and using SiLab ICs on their products. I remember SiLab ICs was certified but i'm not sure about US and Canada requirements.
Great to see another project coming out, as Dany asked a few posts up from this one, in the USA / Canada I understand there is a need for approval before the radio equipment is used / sold, the 3DR radios can't be used here as they fail the tests in the UK / EU, even if the band they use is free (433MHz). So I have the same question as Dany, are these approved / certified for use here in the EU / USA / other parts of the world?
It's a good idea to have old XBee footprint as there are huge load of XBee adapters around the world. And those HopeRF modules seems to be fairly good.
Nice work Melih
Nice work! Are there any benefits for us already running OpenLRS TX/RX's? Will this device improve the telemetry performance and if so - will it work together with OpenLRS since both are working on the 433 MHz band.
Oh i forgot,
At the end, 1500 bytes per second bidirectional telemetry is possible.
I remember 900mhz RF modules is licence free in Canada. We can build 900mhz version of it.How about 433Mhz band? is it license free too?
Oh yes, now it is clear.
We are using 50hz (standard PPM) packages, 57600 baud FSK modulation on OpenLRS code and every pack arriving in 4-6ms. (12ms bidirectional) The pack size depends the code. Current pack size is 17 bytes long. 32 bytes is possible. But the range is dropping depends FSK baudrate. For longer range, SiLab are offering 9600 baud.
Anyway, at the and we got 4800-19200 baud bidirectional telemetry. I guess 9600 is the best for most of XBee users, because this is the maximum baud limit of 900mhz XBee Pro modules.
@Melih, I will rephrase (it was a bit archaic...)
I was just wondering how much data you can send in the serial port and receive out the other module's serial port in bytes per second? Can this data rate be maintained bi-directionally?
I am also interested in this. As per Dany, I'm in Canada and we have different rules. I am a ham too, so I am not prevented from using an uncertified transmitter anyway. What would be good for most other people in Canada (and possibly elsewhere) is if the transmitter's RF module has been certified by some organization acceptable to our government. Not necessarily the whole Tx-end module that you built, but just the RF part of the Tx module if you are buying those pre-made (I'm unclear...). [Similar to how manufacturers use an approved AC wall-wart so they don't have to get their plug-in device certified.] Thanks.
PS: Green PCBs not for selling, they are prototypes.Final products will be RED like our other products.