PINNED - Roboteq Controller - developing for powerchairs

[Burgerman]

Any resistor that pulls it down to zero or low volts keeps it turned off unless you add power. Low value ones waste energy and may get hot, too high value may not keep it at the 0v and off as wanted. The on off wire is "floating". So even a 1k resistor should be OK.

The switch just overides the resistor and turns it on. My switch is on the joystick. Its a latched switch obviously. Then you monitor the flashing status LED also on the joystick. The 2 momentary switches control the contactor seperately via a 12v supply to send it open or closed from the permanantly powered 48 to 12V inverter. So both the SSR and the switches work that relay.

[snaker]

So what value is recommended for that resistor? I remembered you drew a diagram and noted the resistor's value inside. I forgot to save that image

[Burgerman]

I think I used the one it said to use in the manual. It was 1k from memory? Maybe 500. See what it says. Both should work. Use ohms law to figure out a sensible value.

[Burgerman]

Works the opposite sense to what I remember. But the exact same things apply. Use say 500 to 1k as this should be fine to keep it low at near 0V. This is what keeps it turned off when power is removed from on/off switch.

The Power Control input also serves as the Enable signal for the DC/DC converter. When
floating or pulled to above 1V, the DC/DC converter is active and supplies the controller’s
microcomputer and drivers, thus turning it On. When the Power Control input is pulled to
Ground, the DC/DC converter is stopped and the controller is turned Off.
The Power Control input MUST be connected to Ground to turn the Controller Off. For
turning the controller On, even though the Power Control may be left floating, whenever
possible pull it to a 12V or higher voltage to keep the controller logic solidly On. You may
use a separate battery to keep the controller alive as the main Motor battery discharges.

https://www.roboteq.com/docman-list/mot ... l-v21/file

[LROBBINS]

Notice that in the diagram from the Roboteq manual the MCU is turned on or off with a SPDT switch - to B+ for on, to ground for off. A 1k resistor could be used instead to pull it low (and probably even 10k or even 100k), but a 1k resistor adds a >24 mA constant load whenever the chair is off. That 1k will also be passing about 0.6W, so make sure it can handle that if you go that route.

[Burgerman]

5 or 10K is a figure that will give a lower heat loss. Esp if you are using 48v battery as a on voltage. I use 12v from the inverter.

[snaker]

I will try 10K and also 30K, 50K too. I see roboteq uses 20K and 33K for its 5V DIN pins.

I move to the next step: brakes wiring.

HDC2460 supports 2 motor brake pins (DOUT1, DOUT2). We only need 1 pin (e.g DOUT1) to control 2 motor brakes, is it right? I draw a diagram as below, is it correct? Does braking generate any flyback current? Do I need to add diodes or something else to prevent that flyback current?

[JMGarage]

Flyback current occurs on brake side of SSR. It is isolated from Roboteq side now.

[Burgerman]

Yes thats how I do it. I still use a TVS across the 5v side of the SSR because its an electrically noisy enviroment, because the roboteq is much more expensive than a 1 dollar TVS and because I have no idea what the spikes look like from the SSR as no sillyscope here. But my fancy fluke shows something! So better a belt and braces aproach for reliability. And what happens if the SSR fails too?

Just fit a 10V or 15v one to each SSR input side. And a suitable one on the brake side too. Remember that this should be either 12 or 24v depending on your brake fitted to the motor. Choose a TVS 5v above this.

[slomobile]

If I plug a USB cable into the Roboteq and a PC with Roborun+ and nothing else (no battery power), should it be recognized as a USB device and/or light the USB light?

I did that and get nothing, no Windows ding, no light, no message. Does that mean my Roboteq is for sure bad, or are there other things to try before my 5w 100ohm resistor and contactor arrive.

[Burgerman]

Dont remember for sure but I think the roboteq must be powered.

[LROBBINS]

The Roboteq definitely must be powered or it's invisible.