I've been working on the protocol and list of functions for the controlBoard...  I'm trying to establish a command structure and serial protocol for the raspi-boards-raspi communications...

So far, for the control board....I have the following..  

Messages will come from the micro to the raspi whenever they're either requested or a condition occurs that merits it.  

Commands are sent from the raspi to the micro, they may request a message, or contain arguments that elaborate on the command.

An example might be:

0xFE 0xF0 0xC0 0xC1 0x01 0xFE 0xFF

Which would be [command_laser] [laser_power] [01] or turn the laser on..

The controlBoard should respond with:

0xFE 0xF0 0xF1 0xFE 0xFF

Which would be and acknowledgement..

I don't have this to a science yet, and this is really my first attempt at doing this so formally.. I'm not sure if I'm going to keep the start, end and flags on there or not.. I usually throw something together that works and leave it at that.. but I would like to make this easy for everyone to understand and replicate..

#define     msg_cuvette_tray            0x10
#define     msg_cuvette_temp            0x11
#define     msg_cuvette_status          0x12
#define     msg_cuvette_tray_pos        0x13
#define     msg_cuvette_pelt_status     0x14
#define     msg_cuvette_stepper         0x15


#define     msg_filter_wheel            0x20
#define     msg_filter_pos              0x21


#define     msg_laser_temp              0x30
#define     msg_laser_power_status      0x31
#define     msg_laser_ttl_status        0x32
#define     msg_laser_good_status       0x33
#define     msg_laser_color             0x34
#define     msg_uv_index                0x35


#define     msg_ccd_pelt_status         0x40


#define     msg_shutter_servo_pos       0x50
#define     msg_shutter_status          0x51


#define     msg_board_ID                0x60
#define     msg_board_serial            0x61
#define     msg_board_status            0x62
#define     msg_board_time              0x63
#define     msg_board_model             0x64
#define     msg_board_version           0x65
#define     req_reboot                  0x66


#define     msg_ambient_temp            0x70
#define     req_baro                    0x71
#define     req_humidity                0x72




#define     cmd_cuvette                 0xA0
#define     tray_open                   0xA1
#define     tray_close                  0xA2
#define     cuvette_peltier             0xA3
#define     req_cuvette_status          0xA4
#define     req_cuvette_temp            0xA5
#define     req_cuvette_pelt_status     0xA6
#define     req_cuvette_tray_pos        0xA7


#define     cmd_filter_wheel            0xB0
#define     filter_select               0xB1
#define     filter_reset                0xB2
#define     req_filter_ID               0xB3
#define     req_filter_status           0xB4
#define     req_filter_count            0xB5
#define     req_filter_pos              0xB6


#define     cmd_laser                   0xC0
#define     laser_power                 0xC1
#define     laser_ttl                   0xC2
#define     req_laser_good_status       0xC3
#define     req_laser_color             0xC4
#define     req_laser_temp              0xC5
#define     req_uv_index                0xC6


#define     cmd_ccd_peltier             0xD3
#define     ccd_pelt_power              0xD4


#define     cmd_shutter_servo           0xE0
#define     shutter_open                0xE1
#define     shutter_close               0xE2
#define     shutter_deflect             0xE3
#define     shutter_alternate           0xE4
#define     req_shutter_state           0xE5
#define     req_shutter_status          0xE6


#define     packet_start                0xF0
#define     packet_ack                  0xF1
#define     packet_flag                 0xFE
#define     packet_end                  0xFF