sorry, but I do not understand why you would reply to a post three years later. It just doesn't make sense to me.

Plus an M5Atom Lite doesn't stack well with any module as it doesn't have the M5Stack bus.

Thanks
Felix

On the other hand i realized that reading the Position of a servo, like it is shown in the Arduino example-code of the Motion Kit, is not sufficient as sensory-data (it just represents the applied position/velocity). Due to physical interaction i want to track the real, measured angle to compare with the desired.

So in the long run i'll use servos with Position-Feedback to read the angle from the additional wire. As noob its hard to compare any specs, but the "KST MR320 PF" may be appropriate as replacement (still confused about the min and max angle it can take, it must not turn infinite, but a range of at least 270° would be great).

For the current prototyping, i will extend each servo with an Angle-Module (potentiometer), combined with a PbHub and connected to the Motion-Kit. This may be a bit overkill (in cables and weight), but cheaper and sufficient to have a nervous-system as processing-inputs.

Maybe this sounds reasonable. Sadly the ATOM Motion Kit is currently Out of Stock

edit: in case the servo-controls can not be passed easily/quickly though the row-connection (e.g. the data needs to be received and sent by each ATOM with major delay), it may make sense to connect them using a PaHUB2 and an additional ATOM for parallel distribution?

looking at the schematics I don't see a path from the 5V the M5Stack device provides to the outputs of the servos. I think that statement "When the battery base is used for power supply, the maximum output power is 5V / 2A". is wrong. Also a little below there is another statement "The module must use the external power supply of DC interface when driving the servo." which contradicts the first one.

That said, I don't own this particular module so I cannot say for sure what is correct and what not.

Thanks
Felix

@ajb2k3 yes makes sense, thats what the SERVO2 module shop-description says, i just get it to understand slowly ;D (just discovered the Documentation of all the M5 parts!) since i like to use the 360° servos with speed and direction control via PWM it may be possible to ensure (in software) a limit for the applied power in total.

Looks like bridging the 30 pin MBus over some short distance with a cable is kinda overkill so a single stack it shall be.

Power management strongly depends on what the servos have to lift, so overall weight-balance/efficiency of all parts is what its all about then in the long term (even when plugged into a full power source).

So i want to get my hands on these pieces soon and start digging. happy to share some progress here :D
Thanks for your kind and fast replies :D

edit: here is the stack, quite simple. (hope these servos do not fry to soon):

You will need to add a 200ms wait at the end of the program loop (or was it 500ms) to slow down the command transmissions otherwise they will fry (I have learned that the hard way after killing 3!)

As @felmue stated, the battery packs will not power the servos, the servos will only be powered from the external supply. If you try, the Fire will suffer from "Brown outs" and keep resetting when more then a few try to operate.

just to be clear. The servos attached to the SERVO2 module will not be powered from the Battery Module (or the battery bottom of the FIRE). The Battery Module will only power the M5Stack device.

The SERVO2 module has a separate VBAT_2 line which is not connected to the VBAT of the Battery Module or M5Stack device. Check the schematic here. Subsequently the magnetic charger will only charge the battery for the M5Stack.

You'll need to attach a separate battery to the SERVO2 module directly at the DC INPUT (6 - 12V) using the provided thick wired cable. And it probably will need substantially more capacity than the 500mAh of the Battery module anyways. One servo has a rated Locked rotor current of about 750mA and your battery needs to drive 12 of them. See specification here.

And you'll have to charge the battery for the servos with an external charger.

I would probably start w/o the battery for the servos and initially power them through an external power supply. With that setup you could measure the DC current of the working robot and then depending on how long it should run from battery decide on the size and capacity of the battery. (Which will add additional weight to the robot.)

Thanks
Felix

Looks like bridging the 30 pin MBus over some short distance with a cable is kinda overkill so a single stack it shall be.

Power management strongly depends on what the servos have to lift, so overall weight-balance/efficiency of all parts is what its all about then in the long term (even when plugged into a full power source).

So i want to get my hands on these pieces soon and start digging. happy to share some progress here :D
Thanks for your kind and fast replies :D

edit: here is the stack, quite simple. (hope these servos do not fry to soon):

That said the modules communicate using I2C and can be driven but you would need to alter the I2C address of each module to use have separate address and separate power supplies as 24 servos will cause brownouts (I get brownouts with only 6 servos if I don't use a separate power supply. If you change the I2c address' they can be stacked together and use only one external power supply.

its great that the FIRE does have a Battery-Bottom already and i assume this is a very basic setup now. maybe it would be more straight forward to make a single stack but making two interconnected stacks like in the image is surely possible.

Maybe removing the Battery-Modules and get the power right instead. (Though i really like the magnetic charging-connector ;)