Firmware update using "Boot Loader"

A firmware update via "boot loader" allows to flash Avisaro 2.0 products even if the original firmware is not functional anymore. In most cases this comes in to play when a firmware update using the regular methods failed due to power glitch or other things.

FOR EXPERTS ONLY

The whole set-up is intentionally kept simple. This way, only few tools are required to build a boot loader yourself.

Requirements

To use the boot loader, the following items are required:

1. Avisaro 2.0 Logger Module
2. 6 strips of flexible wire, about 20cm each
3. A connector boards to provide supply voltage (3.3V)

Preparing the flasher

1. Download the zip-file and copy the content on a SD memory card. The autorun.txt file contains already the necessary commands - so just insert the SD card.
2. The Avisaro Module used as Flasher can be a single Module or it can be connected to a connector board.

Zip File: A14-2.zip (4kB)

Step 1: Preparing the module

Detach any trailor module from the Avisaro Base Modul - the one with the processor on board. This can be done by using a plastic or wood stick inserted between base and trailor module. Twist the stick carefully to lever the two apart. DO NOT BEND THE PINs - they break easily. See here for details (scroll to end of page).

Step 2: Connect

Connect the Flasher with the To-Be-Flashed-Module this way:

Signal	Color	Pin Flasher	Pin Module	Description
GND	black	13	13	Signal and Power Ground
VCC	red	24	24	Power 3.3V (only required if flasher is single module
TX	green	9	6	Data transmit from Flasher to module
RST	black	2	14	Reset line controlled by Flasher
MODE	gray	3	pad	Mode Pin (manual operation)

If the Flasher has its own 3.3V supply, the red power wire has to be omitted.

Click pictures to enlarge:

1) Drawing: Schematic drawing
2) Picture: Wireing with stand alone flasher module
3) Picture: Wireing with Flasher having its own power supply.

Step 3: Start flash cycle

Power up the module to be flashed and than the Flasher (if both have the same power supply, they start at the same time - that is fine). Hold the Mode wire to the small gold plated pad on the Avisaro Base Module. Do that before the green LED on the Flasher module is switched off. Hold the Mode wire until the red LED starts to blink. See video for a demonstration.

The Flash cycle is finished when the red LED stops flashing. It takes about 4 minutes.

This cycle programmed a 'mini-firmware' into the module. This 'mini-firmware' does only one thing: it looks for a SD card with a file called "avi20.bin". This file contains the final firmware. The reason for this step is performance: the bootloader works quite slow.

Verify that the 'mini-firmware' was successfully flashed: the red LED on the Base module blinks quickly. If it does not, repeat the process "Step 3".

Step4: Load final firmware

Now - place the SD card slot onto the newly flashed module. Insert the SD card with the unpacked ZIP file and power on. For the final firmware, it takes only a few seconds to be flashed.

Step 5: Done.

Reassemble the modules they way you need them. That's it.