Sergeant82d
Joined: 01 Nov 2009
Posts: 55
Location: Central Oklahoma
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| Need suggestions for control/variable storage structures |
 Posted: Fri May 06, 2011 5:54 am |
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I am working on a Radio Controlled robot lawnmower - I live on a farm and have a very large yard - which I hope to eventually make autonomous. I want to be sure I make the program extensible. I have the basic functionality down (finally!), and am trying to expand my programming ability by incorporating additional features.
I am including a variety of error messages & display LEDs, for one thing, and am trying to figure out a logical hierarchy for controlling them. I will be using one or more Maxim MAX7221 SPI LED Controllers, and I plan to use one segment line from the '7221 per sub-system. I have the hardware working, no problems there, but I want to organize the control logic so it is uniform and expandable.
I am thinking about an array of structs, each made up of three other struct arrays, as follows:
| Code: |
#define NUMBER_OF_MOTORS 4
#define NUMBER_OF_ENGINES 3
#define NUMBER_OF_MCUS 7
struct MOTOR[ NUMBER_OF_MOTORS ] {
temperature : 16
speed : 16
voltage : 8
current : 8
is_running : 1
is_over_voltage : 1
is_over_current : 1
is_over_temperature : 1
is_over_speed : 1
has_CAN_comms : 1
}
struct ENGINE[ NUMBER_OF_ENGINES ] {
temperature : 16
speed : 16
// voltage : 8
// current : 8
is_running : 1
// over_voltage : 1
// over_current : 1
is_over_temperature : 1
is_over_speed : 1
has_CAN_comms : 1
}
struct MCU[ NUMBER_OF_MCUS ] {
temperature : 16
voltage : 8
current : 8
has_power : 1
is_over_voltage : 1
is_over_current : 1
is_over_temperature : 1
has_CAN_comms : 1
}
struct LOCATION[ item_location ] { // e.g. front_left.motor.temperature = 235
struct MOTOR[] // e.g. middle_engine.mcu.has_power = TRUE
struct ENGINE[] // e.g. master_mcu.has_CAN_comms = TRUE
struct MCU[] // e.g. right_rear.motor.speed = 1250 // Captured pulses
}
//==========================================
typedef enum {
rear_left,
front_left,
front_right,
rear_right,
left_engine,
middle_engine,
right_engine,
master_mcu,
engine_mcu,
contact_sensor_mcu
}; item_location
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While this looks like it will work, it also looks like it will take up a lot of RAM. I am using an 18F46K80 and have 3.8KB, but am already using half of it. Again, not a show stopper, as I am looking for something that works, but I also would like something that makes sense.
The actual members of the structs are not important as I am certain they will change as the execution is refined, but does this look like a reasonable solution?
Thanks for your time,
Brad |
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