I’ve built an MK312-BT.
Frequently is fails to start properly when turned on. The top line of the LCD is a line of blocks. After a few cycles of the power switch, it will eventually work correctly. When the system fails to start, there is no activity (seen with an oscilloscope) on CPU pin 22 which controls the LCD control/pushbutton multiplexer. When the system works correctly, there is a steady stream of short pulses on this pin. I’ve tried adding a Resistor/Capacitor/Diode network to the CPU reset pin to stretch the reset pulse but it’s made no difference. The clock signal at pin 12 is always present, even when the system fails to start, however I’ve changed the crystal and capacitors anyway with no difference. Can anyone make any useful suggestions about what the next step should be to make my system work reliably?
With the bluetooth facility, are there any mobile apps available to remotely control the MK312?
Are there any open source/reverse engineered e-stim box projects that will fit in a pocket?