by pldb64 » Thu Apr 19, 2012 1:31 am
Hi Bruce et al,
Ok - spent another couple of nights playing around with the FLD-02 and the 3rd party telemetery config tool and i've sorted out a few things that might be of use to others that are wanting to use something similar.
My configuration is as follows;
FrSky DHT DIY module
FLD-02 connected to the DHT via the provided cable
Battery Voltage sensor setup to measure 0-13.2 V for 3S packs - changed from standard config which is for 5S packs (explained in FrSky sensor doc)
Sensor is connected to battery side of the ESC (in parallel) and then into the telemetery port of the D4RII Rx
FUC-3 cable used to connect DHT to PC for use with config tool
The confusing part (at least for me) was understanding how to use the settings that were available in the FLD_02 settings screen (called menu). The real "ahaaa" moment for me in using the alarm threseholds was realising that there are only two threseholds that can be set for each of the 3 measures that can be alarmed (A1, A2 analog and RSSI). So for example, the A2 input has the A2_1 and A2_2 thresholds. A2 is what i've setup to measure my 3S battery voltage. So for example, the A2 input could be setup to have an alarm at 11.25V (time to land alarm) and then a second alarm at 11.10V (really really time to land alarm). Once you grasp the 2 thresholds per alarm part - the information in the FLD-02 screens becomes a little more obvious.
The next thing to understand is that you don't put in the desired alarm voltage directly into the FLD-02 alarm setting. You need to put in a number that is the ratio of the desired alarm voltage compared to the full voltage range being measured. Hence since i'm measuring up to 13.2V, and the ratio is based on 256 steps, my threseholds became 215 & 218 (13.2/256 * 215 = 11.086V & 13.2/256 * 218 = 11.24V)
(Note that the other item that needs to be set correctly in FLD-02 to make this work is the divider settings. The A1 setting is 4 by default and should be left as it is. The A2 divider setting is 1 by default. In my case, i need to set this to 4 in order to get the correct voltages and alarms working. If you left the voltage sensor at its default location for 5S, then you'd need to set the divider to 6).
The next thing to understand is that the FLD-02 shows 4 alarm states (0,1,2,3) with 0 being "Off", 1 = 1 beep, 2 = 2 beeps, 3 = 3 beeps.
So for each thresehold you can set what number of beeps you want the DHT to sound for the alarm.
I'd originally looked at this and incorrectly thought i could set an alarm value against each beep count (meaning i could set an alarm value for 0, 1, 2 & 3 beeps) for each item being mesaured (meaning i'd end up with up to 12 alarms)... that was completely back to front! But that's how i interpreted the user interface of the FLD-02. Doh! Lack of usable documentation was a real problem here.
So my final FLD-02 setting for A2 looked like the follow:
A2 voltage divider setting = 4
FLD-02 showing A2_1, set the thresehold to "1 < 218" meaning i get a single beep when the voltage drops below 11.24V
FLD-02 showing A2_2, set the thresehold to "2 < 215" meaning i get a double beep when the voltage drops below 11.09V
You can set similar alarms for RSSI. These are absolute values rather than ratios as described above. Hence you set the RSSI1 & RSSI2 to whatever level you desire. The default / recommended values are 43 & 40 dbm
Similar to the above,
FLD-02 showing RSSI1, set the thresehold to "2 < 43" to get a double beep when signal level drops below 43 dbm
FLD-02 showing RSSI2, set the thresehold to "3 < 40" to get a triple beep when signal level drops below 40 dbm
I haven't yet been able to determine if the 2 beeps for battery voltage sounds exactly the same as the 2 beeps for RSSI levels. If they are teh same, then i'll probably have my final setup as:
1 beep for battery voltage (since i have the 9X/ER9X beeper based on a flight timer anyway)
2 beeps for < 43 dbm
3 beeps for < 40 dbm
Thats about it! ... i've got it setup the way i think is most useful to me.
Finally - using the 3rd party software for setting up the alarms via a PC turned out to be relatively straight forward (once i had the driver installed properly). I used the FUC-3 USB/UART cable that is avaiable from your friendly FrSky distributor. I needed to install the driver that is available on the FrSky website. This installs the SiLabs CP210 USB/UART driver (on XP in my case).
The 3rd party software (free) is then dependent on knowing what Com port your device is listening to. This can be found in your device manager list when the device is plugged into your PC. It should show up under the Ports (COM & LPT) list. This then goes into the window at the top right of the telemetery setting software.
The rest of how to use the software is pretty straight forward given the explanations above of what the DHT is expecting.
If you have your Rx powered up, then you can view the A1, A2 & RSSI data in real time.
Probably better to setup using this 3rd party s/w, but also useful to know how to use the FLD-02 in case you need to make changes at the field.
I'll look to take some pictures and add them into this explanation if anyone is intersted.
That's all for now.
Peter
Turnigy 9x, FrSky 2-Way/Telemetry DHT DIY, Smartieparts BRD, ER9x FW
AXN-Floater (stock esc, motor & prop, HK orange 9g servos)