Seriously Pro F3 flight controller gyro/acc failure

I purchased an Acro Seriously Pro F3 flight controller (FC) recently and having soldered the connectors on and loaded the current firmware, it was time for a pre-installation checkout.

The article outlines a basic pre-installation test that revealed problems that would prevent effective use of the FC.

Acc/gyro checkout

MPU-6050

Doing no more than an acc calibration and allowing initialisation with a stabilised FC, the FC on the end of a USB cable should deliver acceptable sensor responses in Cleanflight Configurator (CC).

This flight controller has two problems:

  • offset in the gyro z axis (yaw);
  • low acc output in the Y axis (roll).

Continue reading Seriously Pro F3 flight controller gyro/acc failure

Flashing SeriouslyProF3 Cleanflight using ST-LINKV2

Introduction

If for some reason you cannot use the bootloader that reads from the USB port via the CP2102, you can resort to programming the MCU chip using the SWD port and a programmer that supports that protocol.

WARNING: there is potential for damage if you get this stuff wrong. No warranty is offered, if you break it, you get to keep both parts.

Example hardware configuration

FlashCleanflightWithStlink2

Above is the hardware configuration for programming. I have used a LiPo and BEC to supply 5V to the SPF3 board (the target), and a clone ST-LINKV2 (~$4 on eBay) is connected to the Serial Wire Debug (SWD) connector on the SPF3 with a custom cable. Note that you cannot use USART2 concurrently with SWD.
Continue reading Flashing SeriouslyProF3 Cleanflight using ST-LINKV2

Cleanflight – initialisation failure beeps

I spent quite a while chasing down a problem in a Cleanflight v1.13 flight controller which would not start properly, giving a series of beeps that one might expect hinted the problem.

DS1Z_QucikPrint1

Above is a scope capture of the /BEEP signal, five short beeps (50ms ON, 50ms OFF) then four long beeps (250ms ON, 250ms OFF). Continue reading Cleanflight – initialisation failure beeps

MultiStar 5200mAh 3S Lipo – initial tests

This article documents initial tests on a MultiStar 5200mAh 3S Lipo.

Two of these were purchased for about A$24 ea + delivery from the HK Australian warehouse.

On delivery, the batteries were served a balance charge to full capacity.

MultiStar52003SAbove, one of the batteries with the usual mods to suit my quadcopters. A heavy heatshrink encapsulation to reduce the risk of battery damage from crashes and flying propeller bits, rocks etc. A little velcro path to help stabilise the battery on the quad, a ‘gripper’ for the balance plug, balance plug secured to keep it out of the props, and a charge indicator for convenience.
Continue reading MultiStar 5200mAh 3S Lipo – initial tests

Lithium battery – 1S protection boards

Some of my projects use a single Lithium cell for power, and the ready availability of low-cost battery protection boards offers opportunity for better projects.

IMG_1472Above, a 1S board rated at 4A and which sells for about A$1 posted in lots of 5.

Specifications:

Description:
New and good quality
Use BM112 protection chip + AO8810 MOS tube
The protection board is used to protect the battery overcharge, over discharge, so can’t use as a charger,when you want to charge the battery you need to use the dedicated charger,because the protective board has a time to response to the short circuit, can’t to connect too large instant impact current, such as drills and so on

The main performance parameters:
1. PCB Size: 39 * 4 * 2mm
2. Overcharge protection voltage: 4.2750 ± 25MV
3. Over-discharge protection voltage: 2.88 ± 75MV
4. The overcurrent protection: 4-8A
5. Continue working current: > 4A

Note: Only for the equipment which instant start-up current less than 4A,those starting current instant is great, such as high-current motors, drills, etc., are not suitable for use.

IMG_1473

Above are protected battery assemblies based on the board and a 1200mAh LiPo (sells for about A$4) and Panasonic 18650 Li-ion 3400mAh (sells for about A$12). The connectors used are 3A rated JST RCY connectors as used in RC battery applications and readily available with tails for way less than A$1 each set.

The 18650 cell has tags spot welded to the battery contact points, the LiPo has contact tags as supplied.

To use these, the power source needs to supply about 4.5V so as to ensure charging when necessary. The power source needs to be current limited unless you choose to depend on the protection boar’s limit.

RC PWM – ON/OFF switch

This article describes a remote ON/OFF switch which uses an RC receiver and adapter chip to convert the RC PWM signal into an ON/OFF output. (Suitable RC transmitters are on hand.)

The immediate application is for remote ON/OFF PTT or KEY of a transmitter for field strength testing at various locations.

Background

Remote control hobbies have long used a multi channel digital proportional protocol for control of planes etc. The simplest multi channel receiver has an independent PWM output for each servo.

The PWM signal is a 1000-2000µs pulse with a repetition rate from about 50Hz up to 500Hz or so, the duration of the pulse conveys the information.

Implementation

The converter chip is a ATTiny25 MCU with firmware that monitors the PWM stream and provides ON/OFF and OFF/ON output pins. For the immediate application, the ON/OFF (or non inverted) output drives a 2N7000 FET with ‘open collector’ output suited to the PTT and KEY lines of most modern transceivers.

The firmware ignores PWM signals with duration outside the range 900µs to 2100µs, and switches ON at 1600µs, and OFF at 1400µs to provide some hysteresis. If PWM input is lost for 125ms, the output will fail safe OFF.

rcsw01Above is the schematic. The 2N7000 is good for 60V, can handle up to 100mA without a heat sink, and had a body diode to absorb transients if the load is a relay. Continue reading RC PWM – ON/OFF switch

Trial of prototype stand alone GPS logger

An upcoming project calls for a stand alone GPS logger.

The requirement is for a GPS stream that allows correction using RTKLIB, but this trial is of a lesser GPS as proof of concept.

SAGPS001

Above, the equipment consists here of a Ublox NEO-6M based GPS module (~A$15 incl on eBay) at left, an Openlogger (~A$15 incl post on eBay) at right, and a 12V-5V converter (~A$7 from Hobbyking) at bottom. The latter is a 5A converter, way overkill, but it was on hand. The GPS module has a 3V regulator on board for the NEO-6M chip.
Continue reading Trial of prototype stand alone GPS logger

The BLHeli sojourn is over

I was an early embracer of BLHeli ESC firmware on a Silabs based ESC, the Hobbywing Skywalker 40A UBEC.

Skywalker40A

The ESC looked to have quality hardware, and BLHeli was choice in aftermarket firmware.

The Skywalker did perform better with BLHeli than the stock firmware.

When BLHeli was released for the AVR based ESCs, I gave it a trial both on the bench in instrumented tests and in the air on a couple of quadcopters with different ESC / motor / prop / FC combinations.

I cannot say that BLHeli for AVR was any better than SimonK, and generally poorer though not much poorer.

More recently, users have reported some serious issues through BLHeli 14.0 and 14.1, and I removed the Skywalkers from service out of concern there were problems to be fixed. Continue reading The BLHeli sojourn is over

NAZE32 / Cleanflight trial

Overview

The Naze32 is hardly new, but it does seem to have reached a maturity where it, alternative firmware and the support tools are functional and fairly stable.

The article describes a project to fit a Naze32 to an existing quadcopter that used a Multiwii flight controller on a Atmega 328P platform, and initial perceptions.

The 32bit processor at 72MHz provides a lot more computing power than the old 8bit processor at 16MHz.

Implementation

An early decision was made to try Cleanflight as first option, as it appears to work well, is responsive for user issues, has a good PC client and is configurable from Arduino using the EZ-GUI client that I use for Multiwii.

Naze32Above is the Naze32 undergoing Bluetooth testing before fitment to the quadcopter. Continue reading NAZE32 / Cleanflight trial