One of the “challenges” with the Raspberry PI Hat size/format is that I always lack space for connectors. The 8 x DC Motor controller is an excellent example as I can manage 8 motor controllers, but adding connectors that support right angle is a challenge. It is not that the connectors don’t exist, it is…
An updated draft of 8xDC Motor Hat with TVS diodes and spike cutters. I am not happy with the connectors here. They are “ok”, but they are not easily to mount from within a stack and a bit expensive. I need to find alternatives. The 5.08 Power Connector is fine, it’s the 2.54 pitch motor…
What “PWM” resolution will the 32xServo Hat Use? I have not given the question much concern, but I notice that someone advertise 12 bit resolution on similar products. I tested the same Circuit they use earlier and decided against using it because it’s I2C interface was to slow in making multiple servo position changes simultaneously. I simply could…
Not very exiting, but it has taken me most of the day. This is the revision 1.1 of the 32xServo Hat. Just for the record – the red lanes are actually ground plane so it will all be covered with GND – I just switched it off for the picture. Added optional TVS diode on…
Permanent storage of configuration and run-time parameters is not straight forward with small, embedded solutions as the build in Flash only allow large pages and have a limited number of re-writes intended for program download only. Older MCU’s used a build in EEPROM for this purpose that have been removed from modern MCU’s, so we need…
This is a dumb blink demo with a console output just to show that it actually works. I have used Visual C++ and later Visual Studio since 1995 so I am not surprised that things work smoothly. A few buttons on my PC to install this, a sudo command on raspberry pi and it just…
Funny how things work out some times. I initially planned for this to be a more narrow board, but had to extend the height to 40mm due to MCU and connectors. This left space unused on top and bottom of the driver making it easy to add mounting holes for an adapter and now a…
One of my main concerns for some time have been to find a free development kit that actually works for Raspberry PI. I intended to develop directly on the PI, but the drawback with that is that I need a 3rd screen + keyboard/mouse and I simply have no room for it as is. The…
Earlier I had a BEMF issue with my smaller motor controller, so I have been reading up on other peoples experience and solutions to design my own. What I came up with is 3 changes on the MC4X15A. Added a 0.33F super capacitor on 3.3V protected by a TVS (on the back) at ca 4V.…
The original current sensor logic will use a shunt between the lower HEXFET and ground (low side current sensing). This is fine for 3-phase, DC or Stepper motors, but it will not enable measuring of current on a single, stand alone Half-Bridge. An alternative way of doing this that fix this issue is to measure…