AstroBox M4 inside

Here are ugly internals:

• one relay module with four relay ports, used to gate power outlets for DLSRs and multipurpose 12V; one relay is used to control the shutter release of DSLR (NanoPi has only one serial port, used for telescope so I had to control shutter with GPIO&relay)
• two DC/DC voltage convertors, one from 12 to 5V for powering NanoPi M4 board, one from 12 to 7.4V for powering DSLR cameras
• one PWM module which takes as input the hardware PWM from NanoPI and 12V DC, output is modulated 12V, used to power dew heater
• one module to convert serial TTL levels to RS232, to control the telescope mount