Tinybee with dual Y motors

[Mattmannz71]

Hi, planning to run an MKS TInybee with dual Y motors seperately controlled. I am using the web builder and have selected auto squared under the Y axis which I assume gives me 2 Y axis.

looking at the provided board map for the Tinybee when running dual motors on an axis ie 4 motors it wants to use the probe pin as the limit switch for the 2nd Y axis motor (E0) but won't if it's already defined. Am I reading this correctly?

How can I setup another pin (appears to be a few spare ie TH1/2) to use as either probe or the second Y axis limit?

Appreciate all the help.

Cheers
Matt

#if PROBE_ENABLE || N_ABC_MOTORS == 0
#define AUXINPUT1_PIN GPIO_NUM_35 // MT_DET
#endif

#if N_ABC_MOTORS >= 1
#define M3_AVAILABLE // E0
#define M3_STEP_PIN I2SO(10)
#define M3_DIRECTION_PIN I2SO(11)
#define M3_ENABLE_PIN I2SO(9)
#ifndef AUXINPUT1_PIN
#define M3_LIMIT_PIN GPIO_NUM_35 // MT_DET

[terjeio]

Somebody has to check the termistor inputs, since I am not sure if they can be used for digital signals due to the RC network present.
There are no R or C values in the schematic so it is impossible to calculate the voltage levels reaching the MCU.

[Mattmannz71]

Thanks for the quick reply - half way down the page there is an inputs section here which has a schematic, does that assist?

http://wiki.fluidnc.com/en/hardware/3rd-party/MKS_TinyBee

If these can't be used as inputs, is there another method for running limit switches for both Y axis as well as a probe or do I need to share a limit switch?

Cheers
Matt

[terjeio]

The schematic does not have values for the components so it is useless. One way would be to measure the voltage at the MCU when driving the inputs high and low to see if they are within specs. Best would be to get the component values so that the voltage can be calulated along with the response time of the RC network vs the MCU pin threshold values. Too long could add significant probe overshoot...

[Mattmannz71]

Thanks again for a great reply. So looks like sharing an input is the only option. Doesn't look like the board map config file allows for this or am I reading it wrong?

Cheers
Matt

[terjeio]

So looks like sharing an input is the only option. Doesn't look like the board map config file allows for this or am I reading it wrong?

It does not. It would be helpful if someone could measure the voltage on a thermistor pin (at the MCU) with the input (at the connector) floating, pulled to 0V and pulled to 3.3V.

There is code available for sharing a limit switch input that may be used, if added then it should be documented by the board manufacturer like OpenBuilds does for the Blackbox 32?

[Mattmannz71]

Thanks for all the help thus far, I will have a look and see if I am able to measure the voltage.

When I use the web builder for this board it allows me to select auto squared for the Y axis, how does that work if there is no limit pin for the second Y axis?

[terjeio]

how does that work if there is no limit pin for the second Y axis?

It cannot work, but with code such as linked above the Z limit input could be shared with the second Y-axis. Z is typically homed separately and first so that is why it can work.