Friday, April 03, 2015

DIY conversion of an AfroFlight Acro Naze32 to the full version

Introduction

This guide applies to at least rev4 and rev5 of the PCB, however only rev5 has the dataflash option.

This will guide you in adding:
  • Barometer
  • Magnetometer
  • Dataflash (EEPROM)
  • Capacitors to suit the above
This is a "DIY" guide, but most of it requires surface mount soldering experience and equipment, i.e. solder paste, hot air gun, tweezers, flux, and good eyesight.

The Naze Schematic PDF is here: https://code.google.com/p/afrodevices/downloads/list

I have included links to Element 14 (Farnell), but you can use octopart.com, digikey.commouser.com, or your favourite component supplier to get the parts.

Hints

  • Remove any existing solder from the pads before you start.
  • Do one section at a time, testing with USB connection to Cleanflight as you go.
  • If you use IPA to clean the board, it will mess up the barometer until it dries out.  The barometer's datasheet warns against getting anything in it at all!

Shopping list

Dataflash (EEPROM)

Part: M25P16 - http://au.element14.com/micron/m25p16-vmn6p/memory-flash-serial-16mbit-8nsoic/dp/1734973
Cost: $2
Datasheet: http://www.farnell.com/datasheets/158118.pdf
Decoupling capacitor: 100nF 0603  (see below)
Orientation: Pin 1 is on the side with the bevelled edge.  It goes by the indicated pin on the PCB.
Skill level: Medium-easy.  Can be done with a soldering iron, but the capacitor can be a bit fiddly if you don't have fine tipped tweezers.

Note that this a 16Mb (megabit) chip, giving 2 megabytes of storage.  A few other chips, up to 128Mbit, are supported by the Cleanflight firmware.  See lines 48 to 52 of the source code here: https://github.com/cleanflight/cleanflight/blob/master/src/main/drivers/flash_m25p16.c -- currently the list is: M25P16, N25Q064, W25Q64, N25Q128, and W25Q128.

Barometer

Cost: $12
Datasheet: http://www.farnell.com/datasheets/1756128.pdf
Decoupling capacitor: 100nF 0603 (see below)
Orientation: Pin 1 is the pin on the underside with an extra dot beside it, and there is a corresponding dot on the top of the package.  This pin goes towards the inside of the Naze PCB.
Skill level: Medium.  Requires hot-air gun, solder paste, and some experience with this sort of job.

Magnetometer

Part: HMC5883L - http://au.element14.com/honeywell-m-ps/hmc5883l-tr/magnetic-sensor-on-tapereel/dp/1886419
Cost: $4
Datasheet: http://www.honeywell.com/sites/servlet/com.merx.npoint.servlets.DocumentServlet?docid=DCB000D72-C325-A8BE-588A-322B3EC915DE
Decoupling capacitors: Two of 100nF 0603 (see below)
Other capacitors: 
Orientation: Pin 1 is marked on the package with a dot, and goes on the innermost edge of the footprint.
Skill Level: Advanced.  The pads on this package are tiny, and are completely underneath.

Decoupling Capacitors

For all decoupling capacitors, use a 100nF 0603.  For example:

What Goes Where

Overview

To get a general idea of what goes where, see the following.  The cleanflight firmware detects what is present when it starts up, so you can do as many or as few of these as you wish.


Dataflash

The dataflash and decoupling capacitor:


Magnetometer

The magnetometer, decoupling capacitors, and two other capacitors used by the chip:

Barometer

The barometer, and decoupling capacitor:

Finished

All components fitted:


Magnetometer and Barometer readings in Cleanflight: