Stiga autoclip 325 transformation (Building thread)

[Bracame]

Hi all,

Starting discussion is here : https://forum.ardumower.de/threads/stiga-autoclip-325-transformation.25297/

My project is to use Ardumower + CaSSandRA code on a Bananapi to drive my 325.

All electronic will change and i want to use stepper motors for the wheels.

Place is not large and i need to put all the part in a 210X100 mm PCB like that :



Stiga chassis :



Actually ... When my wife watch the TV, the TV watch me writing code .

First test soon i hope.

Alexander(s) -> Thank you for those great developments : Ardumower and CaSSandRA .

Christophe

 

[EinEinfach]

Nice project… couldn’t identify all planed components but what I see looks good.
The green JYQD driver for mow motor is a very good choice. I‘m using it by myself since two years without any troubles.
What is your plan for low level stuff, odometry etc.? What kind of mcu do you want to use?

 

[Bracame]

Hi,
Bananapi M4 will be the brain (with Ardusimple GPS kit).

Maw : BPI-M4 PWM -> Level converter -> JYQD -> Brushless.(RPM measurement ... I wonder : Capture pulses in isr (will warm the BPI) or measure voltage with a frequency to voltage converter (resistor, capacitor, diode).

Wheels : BPI-M4 SPI -> TMC5160 pro -> Stepper motors. TMC5160 is able to measure torque and detect stall, "Xactual" registry give the step mowed : Perfect for odometry. I hope to find good setting for those TMC .....

Voltage/Current measure : BPI-M4 I2C -> ADS1115 ADC (4 channels 15 bits)

+ Relays, rain sensor, stc .....

I need a low latency with Linux but unable to patch BPI BSP kernel with RT_PREEMT patch ..... To do some tests ....

 

[bernard]

Wheel ---》stepper motor ???
Why not brushless one ?

 

[Bracame]

Wheel ---》stepper motor ???
Why not brushless one ?

Stepper look to be the best solution (to my eyes) since driver like TMC5160 can measure torque/current and stall.

And ...Stepper are brushless

 

[bernard]

Stepper look to be the best solution (to my eyes) since driver like TMC5160 can measure torque/current and stall.

And ...Stepper are brushless

Yes of course, but the working mode is totaly différent .What about the power consumption ?
Maybe @Fürst Ruprecht can give more info about that

 

[Bracame]

....What about the power consumption ?

https://www.analog.com/media/en/technical-documentation/data-sheets/TMC5160A_datasheet_rev1.17.pdf-> CoolStep mode

 

[Bracame]

..The green JYQD driver for mow motor is a very good choice. I‘m using it by myself since two years without any troubles.
...

Hi,
I put a "shunt" resistor on the JYQD, value 0.05 ohms to use the JY01 current regulator -> Did you try this ?
Holidays soon here : I will do some try.

 

[EinEinfach]

Did you try this ?

Nope, don’t know what do you exactly mean. Is there something in data sheet about that?

 

[Bracame]

Here :

"According to Ohm's law, we only need to change the R value to change the value of the protection current,
so JY01 in the current protection is very flexible (described in detail later"

"
b) Overload protection and current sampling resistance setting：JY01 has perfect overload
protection function，it has overload protection and abnormal current protection function
when the current sampling resistor value R is correct set. When Is pin voltage meet to
0.1V,overload monitoring will start,and turn to Constant current state,the drive current will not
change, no matter the VR voltage getting higher or lower and the load getting bigger or
less.In this state,JY01 will keep offering constant drive power to motor. if the Is pin voltage
meet to 0.2V or more ,the protection will activated in 4.5 μs."

So 0.05 ohms make me a 2A overload protection (50W is good to maw) ....

 

[Bracame]

Hi,

@EinEinfach, did you do this mod (JYQD limitation) ?

Actually, y glue (epoxy + thermal compound) dissipators on the hot chips on the Bananapi M4 PCD -> Hope a natural cooling.

Wiring some parts soon.... (I2C loook very very slow without slave .?.?)

Christophe

 

[EinEinfach]

did you do this mod (JYQD limitation) ?

Nope

 

[Bracame]

Ok, i will test and return the information.

Main board in construction :


Actually wiring and slowly check BPI-M4 commands .... Code compile and run well, just some "time" issue on the PID -> More than 10mSec cycle :-|

 

[Bracame]

Hi,
5V parts are wirred (TXS108 replaced by a 74HCT541 for the outputs) :

But i have an issue : BPI-M4 pin are in hight Z state at start but at GND state if shutdown -> This make my relay board "all ON" ....

What is the best solution ? My mind is to modify this relay board to use 5V->Relay ON .....

If i'm not alone here, a question : My Wyfe wonder me to add a ir-sensor to detect the dog has an obstacle ... I said "yes" -> Your opinion ?

Christophe

 

[Bracame]

Hi,

Some building news : (All is home made)

Maw motor bearing box to preserve brushless motor :

Parts :


Assembly :

Wheels motor parts :

Assembly :
GPS base print (a standard Ardumower one ) :

And Code change :

Switching to CDEV Gpio management (V1 on Linux Kernel V4.XX) -> Faster than the "wirring" library.

This day : Soldering a lot of mosfets (hidden on the picture) and a lot of wire .... To finish soon.

Place is less, not easy to wire all

 

[Bracame]

Soldering last wire and test soon :

 

[Bracame]

Hi,

Some news.

Mechanics work fine and with some arrangement goes in the small place available :



.... And electronic part drive very well the steppers motors with current optimization and stall detection (also give the steps for odometry) @ 4Mhz on the SPI bus).

PWM also work fine to drive the JYQD Brushless motor (with the 2A limitation) ... All is OK



But

I can't use a Bananapi (RTD1395) pin as input. A lot of try but no result .... This is hard to be stoped for an issue like this !

Keep you informed ;-)

.... Any help about the GPIO input bug is welcome

Christophe