MS3Pro + ESC + Brushless Motor to drive Speedometer

[280GE 1JZ]

Hello all,

It's been a very long time since I read this forum. I got a project to run my car speedometer with a brushless motor and ESC from R/C. The problem is ESC receive a unique PWM Signal. 1ms pulse every 20ms will be translated to stop and 2ms every 20ms will be translated to full speed. Is it possible to replicate this signal from MS3Pro?

I'm Using MS3Pro with 1.4.0 and TCU with transmission firmware 1.0.1 connected with CAN. Thanks all.

[CRSTune]

Sounds like it operates at 50Hz with 5% duty cycle to mean stop and 10% duty cycle to mean full. You could do this using the "generic PWM output," the only problem being that 50Hz is not a selectable frequency.

[racingmini_mtl]

Sounds like it operates at 50Hz with 5% duty cycle to mean stop and 10% duty cycle to mean full. You could do this using the "generic PWM output," the only problem being that 50Hz is not a selectable frequency.

Even if it was selectable, you would have a very poor resolution.

My TinyIOx does have an R/C servo output option for its generic PWM output. And you can use any data from the MS3 as an input to the PWM signal and you get the full resolution for the 1ms to 2ms range.

Jean

[280GE 1JZ]

Sounds like it operates at 50Hz with 5% duty cycle to mean stop and 10% duty cycle to mean full. You could do this using the "generic PWM output," the only problem being that 50Hz is not a selectable frequency.

Even if it was selectable, you would have a very poor resolution.

My TinyIOx does have an R/C servo output option for its generic PWM output. And you can use any data from the MS3 as an input to the PWM signal and you get the full resolution for the 1ms to 2ms range.

Jean

Hi Jean,

Thanks for your reply. Can we use TinyIOx independently? I got another speed sensor directly to driveshaft output with 12 volt pulse output. Can we use this as input? And how to configure the TinyIOx? Thanks

Regards,
Doddy

[racingmini_mtl]

Yes, you could use it independently. But that might be a bit awkward to setup because the pulse input on the TinyIOx only gives a raw timer count and not a speed input. That means you would need to work with time interval between pulses instead of speed.

There's also the fact that this is not a linear relationship (speed versus interval) but a 1/x relationship so I don't know how precise the linear interpolation of the generic PWM output would be. You would have 16 points which are exactly what you want and everything between those would be a linear interpolation. That would probably be good enough for a gauge.

And you will have to make a conditioning circuit to transform the signal into a 5V pulse signal.

Jean

[spyder]

When faced with a similar problem I used an Arduino to "read" the gearbox output pulses and drive a stepper motor fitted to the back of the speedo. It could just as well drive a brushless motor.

[280GE 1JZ]

When faced with a similar problem I used an Arduino to "read" the gearbox output pulses and drive a stepper motor fitted to the back of the speedo. It could just as well drive a brushless motor.

Well, I'm very unfamiliar with programming code. Care to share the code and schematic? Thanks