WheelchairDriver

The controller can only be turnt on when the joystick cover is alligned probably with the PCB

.... ODD! I have not come across this problem with any of the various pod types.... BUT ...I have not had a NEW VSi in my possession.

download/file.php?id=15768&mode=view

Your pic seems to show a possible microswitch "tongue" in lime green in the left hand side casting rail.

woodygb wrote:Strange question to ask about the ribbon pitch ...measure yours and tell me what your ribbon pitch is.

The 4 voltages ( 2 off X & 2 off Y ) MUST be 2.5v at start up AND Vs/2 must also be 2.5v.

This might help you ...

ard joy.jpg

This is what we measured with a DMM

Neutral Voltage: 2.5V

Pin 2 Left= 3.8v , Right=1.2v

Pin 7 Left=3.9v , right= 1.1v

Pin 4 Forward= 1.1v , Reverse= 3.9v

Pin 5 Forward = 1.1v, reverse = 3.9v

Good ... any problems with making an external interface?

woodygb wrote:Good ... any problems with making an external interface?

nope. But I am wondering what is the value of the digital pot?

You mean Ohms value?

The part number of the Digital pot is written on the schematic that I posted and it equates to only one resistance value.

I will leave you to Google it.

woodygb wrote:You mean Ohms value?

The part number of the Digital pot is written on the schematic that I posted and it equates to only one resistance value.

I will leave you to Google it.

The 4261 consists of 5kohm, 10kohm, 50kohm and 100kohm. I was wondering which value you used in the diagram?

MCP4261-502E/P, Digital Potentiometer 5kΩ 257-Position Linear 2-Channel Serial-SPI 14 Pin, PDIP

You could have done a bit of resistor network math.

The schematic shows the MCP4261 that is wired as 2 off resistors in parallel , each end is fed by a 1k resistor .

So we have 5v feeding a resistor divider consisting of ....0v > 1k ( 1.3v required at this point ) ?Ohms ( 3.7v required at this point) 1k < 5v ...
solve for ?Ohms....then double it.


https://www.electronics2000.co.uk/assist/assist.exe

You can also see from the schematic that I have bifurcated the outputs of the MCP and fed them to the relevant pins.