I thought it might be useful to give a bit of background on what this forum is for.
3DRobotics have just released a set of telemetry radios based on the Si1000 chipset. The ArduPilot developers (particularly Mike Smith and myself) have been working hard on the firmware for these radios for months now, trying to make them ideal for APM telemetry.
These radios are unusual as they are open source and extremely configurable. That means that there is a lot of scope for diydrones members to get involved in tuning of the radios, and in adding new functionality. That is what this forum is for.
The Si1000 chipset has a huge number of configuration registers. We've spent quite a lot of time selecting the best register values for use with APM, but there is still a lot of scope for more experimentation. For example, I'm planning to do a test flight soon to see if enabling manchester encoding gives better or worse range at various data rates.
Similarly, there is a lot of scope for adding firmware features to make these radios link really well with antenna trackers and other radio add ons. We've already got them talking to APM in a much more advanced way than an Xbee can, but there is a lot of scope for taking it even further.
The basic theme is that these are DIY radios. We've put together functionality to make them work really well already, but the real potential is from the community getting involved to make them even better.
So get involved, and let's bring to telemetry radios the same sort of community development that has made ArduPilot so much fun to be involved with!
Please, where can the ampifier be bought and do you know of a more powerful one.
Thanks for the infos..........
What kind of telemetry ranges have managed to get with 3dr 433MHz stock modules/antennas?
Needed to install a more recent version of APM, older version was updated but didn't support the 3dr radios as well.
Ok, now back to tweaking...
I noticed an earlier post about using gold plated right angled headers on the 915MHz air module. I received two Telemetry kits from the DIYDrones stores and both had the following cheaper tin plated headers, so now I have to find an alternative supplier before I can use my radios. This was a surprise since the store shows nice gold plated headers but they shipped me something entirely different which is annoying. I am not sure why you would go to all the trouble of having gold plated pad on the telemetry module and then provide a lower grade tin metal header instead of matching gold plate?
The above is what I received. The following is a photo from the store of the 6 pin right angled header.
There is another issue at the moment with the SMD style 3DR telemetry modules I received, (not the original DIL purple board) and I am not sure if anyone else has noticed this. Both my air and ground modules have a few areas where some attention is needed to fix up incomplete soldering. On the ground modules there was no solder on one pin from the USB port and I remember reading someone else had the whole connector fold up while trying to plug in the usb into the computer. What is a larger concern is the soldering of the HM-TRP radio modules. Although the soldering is reverse flow through the board connector holes, several areas on my air modules looked to have little or no solder. Consequently I have reworked the soldering so there is a little more material for the HM-TRP radio modules. The picture below is my reworked air module.
I notice a few people report intermittent module link up so perhaps have a closer look at the soldering of the HM-TRP radio modules?
You can see the solder filets I have added to the edge of the HM-TRP radio module. I have also touched up the soldering in different places on the ground module e.g USB connector as I am using the 915Mhz version.
Its a pity there is no way to order the DIL version of the air module. These are discontinued as the shop is setup to make the SMD version which speeds up the process. the purple boards look to be a better build quality.
Finally can someone confirm if a special TTL 3.3v to 5V cable is needed to connect the air module to the APM1 board. I see there is a need to buy a separate 3.3V FTDI cable to program the air module which is not available from the diydones store. They do not list this as an accessory under the telemetry section either, so it means the kits I have are unusable as like some the ground and air modules are being shipped out with different versions of firmware. So I assume that since a 3.3V TTl is needed to program the air module the stated 5V connection to the APM 1 may be wrong as well as the doco which states the device is connected to TX RX 5+V and ground?
Hi Earl, looks like you have the earlier DIL style air module. When I asked the manufacturers they changed the design to suit their assembly process and make it more efficient. Both style modules perform the same according to Tridge.
Personally I prefer the earlier package assembly in your picture. The pin connections between the main board and HM-TRP radio module seem more secure / robust. I had to spend an hour or so very carefully reworking all the SMD connections of the HM-TRP radio module in the two kits I received. I found several contact points which looked like they might cause reliability issues over time. In addition, I had no solder in one of the USB connector pins on both ground modules.
I am a bit disappointed I was shipped tin plated right angled headers versus the advertised gold plated version. I also see the antenna connectors are not gold plated like the Xbee pros. I thought in most electronic designs it is not a good idea to mix metals at critical contact points.
These things aside the 3DR radio telemetry works very well. Mine paired up solid and worked perfect on first power up even with the older APM1 code I have on my arducopter at the moment. Its really nice to finally have a ground link in case of emergencies and to monitor the flight stats. I have had a few close calls in the past. Looking forward to my first flight with live telemetry and also doing some range testing.
One thing, I noticed you have used the clear heat shrink on your air module above. Did you have any trouble getting enough heat to shrink this down to size versus risking the delicate electronics. I had lots of problems with the one module, so I am holding off doing the others until I get a better process or heat shrink which is a little better fit and does not need massive amounts of heat to contract.
If it can send serial data it can use any transparent serial connection like the 3DR radios. Tons of those out there... xbee, TI chip radio based modules, etc.. 3DR just happens to be the cheapest and have the best specs.
Outstanding job on the Radios. I received mine today and connection and setup took less than 15 minutes including soldering on the header. I did use some MUCH smaller (1/2 diameter of what was sent) clear heat-shrink that fit better. I doubt that the shrink included with my kit would have shrunk enough for a secure fit. I look forward to "playing" with the telemetry kit on my quad in the coming weeks.
I just got my new 915 MHz installed and it works great with the default settings. I do have a couple of questions: