FRSKY's CPPM at 27mSec - Firmware update with FT_Prog and FTDI cable. Introducing the Issue and the solution: We've talked about FRSky's CPPM signal on this other post that compares it with a standard PPM signal.
The issue is that originally FRSky's CPPM runs at 18 milliseconds. That short period has no space enough for 8 channels plus a proper sync pulse. After carrying that issue to FRSKY, Jani came up with two FRSky's beta firmwares running CPPM at a 27 milliseconds period. We did test it at the DIYDrones Dev Team and it seems to work pretty fine. Some guys at that old post were expressing their worries about the 37Hz update speed from the new custom firmware. Well, now those beta firmwares became official: There are custom firmwares for the receivers D8R-XP and D4R-II on their BetaTestSection. D8R-XP_CPPM_27ms D4R-II_CPPM_27mS About the Updating process: Inside of each update zip file there is a PDF explaining how to update your receiver. Reading their manual you'll see that an FRSky USB cable is necessary.
How to use an FTDI cable: That's it! FrSky DF 2.4Ghz Combo Pack for JR w/ Module & RX. The build quality of this is no where near that of JR, Spektrum or Futaba, but it is adequate.
The PCB of the RX was not mounted flat so the servo pins did not fully line up with the hole in the case. In terms of functions this is perfect, it gains a lock within 1 second, if you switch the tx off and then on, the bind comes back on instantly. Setting the failsafe position is dead easy, just press the rx button for less than one second. One thing to note, there is software available to upgrade this to v2, however, the supplied serial cable will only update the tx module. You need to build or buy another interface to upgrade the rx!! One other thing, the module can support telemetry and non-telemetry rx. Overall, in terms of function this is definitely the 2.4 set to buy.
FrSky DHT 8ch DIY Telemetry Compatible Transmitter Module. FrSky D4R-II 4ch 2.4Ghz ACCST Receiver (w/telemetry) FrSky D8R-II PLUS 2.4Ghz 8CH Receiver with Telemetery. FrSKY ACCST technology is proven, approved by many model associations, tested and reviewed as the leading Chinese 2.4Ghz R/C Technology. If you think DSM2 or FASST is the best, think again! New FrSKY ACCST (Advanced Continuous Channel Shifting Technology) gives you secure radio communicatios in 2.4Ghz band. ACCST 2.4GHz system shifts 80 channels around hundred times per second in the 2.4GHz band. This means that the system is completely resistant to interference in that band.
The Two-way Radio System developed by FrSky provides an additional return link that would be used for monitoring the Rx’s voltage, temperature, location, speed and so on. Compatibility:Compatible with FrSky two way telemetry modules: DFT, DJT, DHT, DHT-U Receiver Specification:Operating voltage: 3.5~10.0VPower consumption: 100mAResolution: 3072Analog voltage: 0~3.3VNumber of channels: 8Range: 1.5km-2.5kmDimensions: 55 x 25 x 14 mmWeight: 12.4g Included.1 x 8-channel receiver D8R-II PLUS.
FrSky D8R-XP 2.4Ghz Receiver (w/telemetry)