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Member postings for Mike Blandford

Here is a list of all the postings Mike Blandford has made in our forums. Click on a thread name to jump to the thread.

05/08/2018 11:25:19

I have an Arduino project that is a SBUS decoder here: **LINK**

By default the output rate is 18mS (for analog servos). There is an option to switch to 9mS.


Thread: Electric setup conundrum
02/08/2018 14:51:22

Peter, if the ESC has a BEC, and is then powering the receiver and servos via the red wire, connecting a battery to the receiver as well is then providing two power sources in parallel, with NO protection to either.

It the receiver battery is lower in voltage than the BEC output, then the BEC will be charging the battery, with no current limit.

If the receiver battery is higher in voltage than the BEC, then the BEC circuit will be powered in reverse. These days, many BEC circuits are "switch mode" operating in "step down". This generally means there is a MOSFET transisistor that switches the flight battery voltage through an inductor directly to the BEC output. Such MOSFETs have a (parasitic) diode that would conduct the opposite way to normal (i.e. pass the receiver voltage back to the flight battery. One result of this is if the receiver battery is connected, but the flight battery is not connected, then the receiver battery will power the ESC. If you advance the throttle at this point, then the motor will start, powered from the receiver battery. There is likely to be enough power for the propellor to injure someone, particularly if they thought the motor wouldn't start because the flight battery is not connected. The amounr of current flowing to the motor may also be enough to overload the copper tracking in the receiver, thus causing damage to the receiver.

If you don't have a "power sharing" circuit to prevent these events happening, then I strongly recommend the red wire is disconnected from the ESC.

If the ESC is an "opto" type, then it doesn't have a BEC and the red wire does need to remain connected.


Thread: New Drone Laws from 30/5/2018
25/07/2018 13:41:32

Well done to all from me as well.

I does seem that my Qudratwirl (4-rotor autogyro) is still limited to under 400 feet (not that I think I'd see it that well above that anyway, and I mostly flew it indoors). Does an autogyro have "lifting rotor or rotors", even though it/they are not powered? I would think so!

Is the Tony Nijhuis Harrier restricted to 400 feet as it has 4, lift generating "rotors"?

Note, I'm not being negative, we have an excellent result, just thinking about clarifying things. Clearly, if in doubt, keep below 400 feet.


Thread: The 2018 Transmitter Survey!
23/07/2018 09:53:03

Andy, what is it about the "Taranis" programming you don't get on with? I'm guessing you mean openTx programming model. ersky9x open source firmware also runs on the Taranis and may be easier to follow:



Thread: New Drone Laws from 30/5/2018
20/07/2018 23:21:05

For interest I put a vario in my aerobatic model (the one in my avatar, 52 inch span) and flew it today while logging the telemetry data. The model is quite light (3.5 pounds I think) and has around 700W available!

For much of the flight I was comfortably below 400 feet, but I did fly in level at around 100 feet then pull up into a vertical roll (single roll) and then do a stall turn. The height peaked at 500 feet, and took only 5 seconds to go from 100 to 500 feet.. Later in the flight I pulled a nice large loop and that peaked at 401 feet, again taking only 5 seconds to go from 70 feet to 401 feet..


Thread: IRange module
17/07/2018 09:38:13

To flash new firmware to the module you compile it using the Arduino IDE. All the power settings are included in the file "multiprotocol.h" like:

CYRF_POWER_0 = 0x00, // -35dbm
CYRF_POWER_1 = 0x01, // -30dbm
CYRF_POWER_2 = 0x02, // -24dbm
CYRF_POWER_3 = 0x03, // -18dbm
CYRF_POWER_4 = 0x04, // -13dbm
CYRF_POWER_5 = 0x05, // -5dbm
CYRF_POWER_6 = 0x06, // 0dbm
CYRF_POWER_7 = 0x07 // +4dbm
#define CYRF_RANGE_POWER CYRF_POWER_1 // 1/30 of the full power distance

So to reduce the output for the CYRF chip (used for DSM) just change the line:


16/07/2018 23:01:06

I doubt they actually know what the output power is! There are 4 RF chips in the module and a single power amplifier. On my DIY module I notice the RSSI readings when using FrSky protocol are lower than when using a real FrSky XJT module, so I reckon the output power for that is lower.

The chip for FrSky (CC2500) can output a max of 1dbm (before the power amp.).
The maximum for the NRF chip is 0dbm, the A7105 is 1dbm and the CYRF chip (for DSM) is 4dbm.


16/07/2018 19:34:03

This all started out as a DIY project, see: **LINK**

The firmware on the module is open source, see: **LINK**

The transmitted power may be adjusted in a header file of the firmware.


Thread: X4R receiver seems to be stuck in CPPM output mode
11/07/2018 18:21:16

The RX4R is a different receiver, the X4R is on the second page of receivers and there is more than one firmware download listed.

If you go to the "bars" display on the Tx, is bar for channel 1 moving?

It may be worth creating a new model on the Tx, if you haven't already done so, to rule out any odd settings on the Tx causing the problem.


Thread: FRSky DIY module
06/07/2018 14:21:27

The switch is to select the mode of operation:

1. Old "V" receivers (not "V-II" receivers).
2. "D" (telemetry) receivers and "V-II" receivers.
3. Firmware upgrade.


Thread: Can't get S8R to stabilise or auto-level
22/06/2018 21:39:15

You "run" the LUA script like the PC configurator program. It reads all the values you may configure on the S8R and lets you edit them. As an example, you could change the "Auto-level offset" for the elevator to correct the nose down of the twinstar, and you can do this on the flying field.

Also, if you find the stabilisation is too mild, and turning the channle 9 gain up doesn't give enough, you can increase the individual gain values in the S8R. They default to 50% for the aileron, 80% for the elevator and 100% for the rudder. All may be adjusted up to 200%. Again, using the LUA script, you may do this at the flying field (e.g. between flights).


22/06/2018 12:16:08

The "latest" items for the S6R/S8R are here: **LINK**. To see what "Quick Mode" is about, download the manual. Under "tools" you may download the latest PC config program (v.1.8.4), and also the LUA script.

In my opinion, it is well worth having the script on the Tx as it allows you to configure all the parameters in the Rx directly from the Tx.


22/06/2018 09:55:13

When "Quick Mode" was introduced, the configuration program on the PC was updated to add the option for setting it. The PC program is at, at least, V1.8.1. The LUA script also changed to add the required setting.

Be careful if trying to configure the Rx while in the model with servos attached. You may find the load on the USB port becomes too high and causes a problem on your PC. Using the LUA script on the radio is just as convenient, and doesn;t need the cable attached all the time.

Ian: The Rx should be fine with 2.1.9, but, as I just mentioned, you may need to update the configuration program on the PC and/or the LUA script.


21/06/2018 22:10:20

Since the S6R/S8R first came out, the firmware has changed to introduce "Quick Mode". This uses only channel 10 to select stabilise/auto-level and doesn't include knife-edge or hover. Quick Mode enabled is the default, so you will need to check this is turned off to use the same settings for channels 10 and 11.

There is a setting you may adjust if auto-level loses height. Using this you may just alter the pitch response while re-doing the "self-check" sets the roll response again as well.

Do you have the STK device to adjust the settings in the Rx, and/or do you have the LUA in your radio for doing this?


Thread: New Drone Laws from 30/5/2018
16/06/2018 15:38:59

A good result, well done from me.

I also did write (e-mail) to my MP and received a letter (dated 11th June) from him today. While much of the letter looks like a printed, standard reply, there is a handwritten P.S. saying " Given your expertise and concern I will pass this on to the Minister"!

I did include a picture of an electric glider (showing it isn't a multi-rotor) and a graph from a logged flight showing very little thermal activity below 400 feet.


Thread: FrSky Taranis - user chat
14/06/2018 12:14:24

Glad you could follow my instructions OK.


11/06/2018 12:36:22

Details for flashing the Orange module are here: **LINK**.


10/06/2018 22:57:30

This is a known problem with that module, there is something wrong with the firmware in it.
The only solution I know of is to update the firmware in the module with the MultiProtocol firmware, however this is not a straightforward operation as the module needs a special programmer (PDI). If you use Arduinos at all, I do have a method of using one to flash a bootloader to the module, then I also have a method of using that to flash the MultiProtocol firmware from the radio.


Thread: bullet connectors
30/05/2018 23:38:23

I use the same, male bullet on the battery positive. I also use short lengths of hardwood dowel (3/8 inch diameter) in which I drill a hole part way through that accepts the male bullet. I then put these over the battery positive connector to help protect from any accidental shorts. I only remove them for charging or when connecting in the 'plane. They are large enough that they don't get lost, I normally slip them into a pocket when a battery is in use so they are easy to find when disconnecting the battery.


Thread: QX7
29/05/2018 13:16:24

Yes it does only apply to ersky9x. The QX7 does include two connectors on the main board for extra switches, intended for switches on the ends of the sticks. Ersky9x also supports these for extra switches.


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