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ZMR250 Build – Part 4 – FC Firmware Flash

In this video I hook up the SP F3 Flight Controller to update the firmware via the Cleanflight Configurator app. Even though I've done this a heap of times I still manage to make mistakes doing the firmware flash. Some of the mistakes include;

  1. Wrong settings in the app.
  2. I'm so used to flashing my Naze32 rev5/6 boards, I uploaded the wrong Betaflight firmware (now I'm using the SP F3 FC).
  3. Leaving the "flash on connect" setting active in the configurator without realising it and interrupting a firmware update before it finished.

I remember reading somewhere that "you can't brick these boards" because the bootloader is stored in ROM. Just short the boot pins and flash again. Lucky for me the boards are resilient in this way as I've had to use the bootloader pins a number of times.

I never did get the 4way BLHeli firmware update to work via the FC board so in the end I gave up on that option and looked at updating the ESCs with a direct connection to the board. More on that in the next video.

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ZMR250 Build – Part 1 – Parts List

The purpose of this build log is to document the process of building a ZMR250 quadcopter complete with FPV and telemetry. My experience building a previous ZMR250 has been that simple problems like outdated firmware can cause major headaches and heaps of Google searching / forum reading to find the solution. The plan here is to document each step no-matter how seemingly simple it may seem


ZMR250 V2.1 Mini Quad Frame Kit w/PDB Special Edition -

Mini DC-DC 12V Voltage Step-down Regulator Module



FrSky X4RSB 3/16 Channel Telemetry Receiver

Upgrade NAZE32 SP Racing F3 Flight Control Acro 6 DOF/Deluxe 10 DOF for Multicopter

Eachine 700TVL ET25 5.8G 32CH 25mW 7-24V Super Light Transmitter

MICRO MinimOSD Minim OSD Mini OSD W/ KV Team MOD For Naze32 Flight Controller



New DALprop 2 Pairs 5045BN Bullnose Propellers for Racing

Emax BLHeli Series 12A ESC For Quadcopter RC250 Mini200 QAV250

SunnySky X2204S-16 2300kV Brushless Multirotor Motor

Foxeer XAT600M DC5V-22V 600tvl Sony Super HAD CCD FPV Camera

5.8Ghz Circular-polarized Omni Cloud Spirit Tx Antenna



Betaflight update to Afroflight Naze32

Having recently become aware of Boris B's custom version of Cleanflight known as Betaflight, I decided to update my Acro Naze32   I made this decision after seeing so much positive feedback from others on rcgroups, Facebook and YouTube.

My notes here explain some of the problems I had to overcome before successfully upgrading to Betaflight. Some of the issues are really minor and might seem obvious to others but at times I was almost going to give up thinking I'd just try out Cleanflight 1.10RC3.

The first hurdle came about after somehow I managed to do an incomplete / corrupt firmware update and the Naze32 board become unresponsive (couldn't connect via the Configurator app). The good news was that I read the boot loader is stored in ROM and "the Naze32 board can't be bricked". I read plenty of posts where people explained how to just connect the two physical boot loader pads on the board and re-flash. Shorting pads on any PCB is a risk if you aren't confident which ones to do so just to be clear, owners of the Afroflight Naze32 ver 5 board here's a picture of the boot loader pads.



I found it easy to solder a lead in place rather than try and hold two pins in place while simultaneously plugging  in the micro usb connector and go through the firmware flash. Once the board has booted with the boot loader pads shorted, set a couple of options in Clenflight Configurator;

Configurator set to flash with bootloader pins connected

Configurator set to flash with bootloader pins connected

And flash to ver 1.9.

The next issue I had was trying to use the "Load Local Firmware" button in Configurator. I kept getting error messages to the effect of corrupt or invalid file and "Loaded bytes" would show zero. I hadn't followed the directions properly to download the file from GitHub. I was right clicking on the Naze Betaflight hex file to download it. The problem was I hadn't clicked through to the screen that shows the "RAW" option.

Hex files location (right click download doesn't work here).

Naze32 Hex files right location to download from. From that screen the hex file will download properly.

After finally uploading Betaflight and connecting via Configurator I could configure my board. My next big issue was that the motors would not spin up at all even though I could see the RC input tab and motors output tab showing all the right signs. If I disconnected the LiPo battery and kept the board powered by USB, I found on reconnecting the LiPo would activate the motors but with two problems 1) they wouldn't disarm ever and 2) full throttle on the input stick translated to maybe 50% output on the motors. Eventually I realised that I had BLHeli version 13.xx on the Afro 12A ESCs and Betaflight needs version 14.xx. No big deal unless like me you've soldered the signal pins directly to the board. At this point though I'd invested too much effort to be deterred. After de-soldering all the signal wires and updating BLHeli to the most current version, I'm happy to report a fully functioning board with Betaflight firmware.
I haven't had a chance to actually fly it yet so that feedback will be next.

As a side note, while I had the soldering iron out, I took the time to run a couple of wires to the VBAT pins. This lets me use the audible beeper and the programmable LED strip to warn of low voltage levels. A handy backup in case I forget to connect the LiPo alarm to the battery before each flight.

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