tsdz2_maxspeed_wheelsize_assistlevel

How to update your stock firmware to have different factory default Max Speed, Wheel Size and Assist Level

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Based on ideas from casainho and hurzhurz found here: https://endless-sphere.com/forums/viewtopic.php?f=28&t=94351&hilit=TSDZ2

Changes in stock firmware are related to following default(without display) values:

max speed to 45Km/h

Original - 0x19(25):
	0x8210:	 a6 19	ld A, #$19
New - 0x2D(45):		
	0x8210:	 a6 2d	ld A, #$2d

wheel size to 20inch

Original - 0x1a(26):
	0x8214:	 a6 1a	ld A, #$1a
New - 0x14(20):
	0x8214:	 a6 14	ld A, #$14

assist to level 3

Original - jumps to $a860 as default (assist level 4):
	0xa801:	 24 5d	jrnc $a860  (offset=93)
	...
	0xa81c:	 20 42	jra $a860  (offset=66)	
New - jumps to $a84a as default (assist level 3):
	0xa801:	 24 47	jrnc $a84a  (offset=93)
	...
	0xa81c:	 20 2c	jra $a84a  (offset=66)

VOAMCA firmware can be updated with this as well. I use it like so. Therefore I switch the motor on with the switch and I can ride my bike immediatelly. I only need my mobile with bluetooth connection if I would like to see the Voltage, Watts, Speed, etc. Of course you can still use your XH-18 or other display as well.

Part One, to change default(without display) Max Speed and Wheel Size:

Put in hexadecimal number format your desired Max Speed (Km/h) into the red square and then your Wheel Size (Inch) into the green one.

Part Two, to change default(without display) Assist Level:

Well, this is a bit a harder. The hexadecimal numbers in the coloured squares are relative jumps to red corner what is starting point for Assist Level 4. Starting point for Assist Level 3 is the blue corner. 0x5d means that there are 93 bytes it should jump to reach red corner. Same logic for 0x42. Therefore to jump to blue corner (Assist Level 3) at orange square 0x47 and at purple square 0x2c are needed to put into.

Schematic for how to switch on the motor, so you can use it without display:

Only the red lines are needed for the switch. You can skip the other part as that for the bluetooth module.