DRV8313 is an excellent driver circuit containing 3 separate half h-bridges that can be used as separate PWM drivers, a DC Motor driver or 3-phase motor driver. Delivering 3.5A max in peak and supporting upt to 60V it is excellent for 12V, 24V or 48V systems. I have made a small motor driver on this before and I only need a few passive components connected to the operational Amplifiers in STM32G491 to create low side current sensors. This will be an excelent PLC module and small motor driver.
The drawback with low-side current sensors are that it is difficult to measure individual currents simply because you will not use the low side on solenoid type connections, so high side current sensing is better, but this require additional circuits that drive cost/complexity. So what I will do is to use four current sensors – the forth measure total current on the PWM- (Ground) channels, while the three others measure motor currents. I have 4 operational amplifiers in STM32G491 so this should work fine.
A 6P 2.54 pitch connector fit exactly on the 17mm available on a 25x45mm module, and this allows me to offer 3 PWM+ and 3 PWM- (GND through shunt) connections – for 3 separate signals you use all 6 and I measure current using the 4th sensor, while for a motor you use 2 or 3 PWM’s and I measure current on low side. It is a few issues I need to consider, but this sounds like a great module that will be fun to use.
CAN (or RS485) is great here because I can make this PCB purple or even pay for multiple colors and hang them with LED strings directly on the chirstmas tree. Fun to come 🙂