BalloonSat Mini Flight Computer

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BalloonSat Mini Flight Computer

• Programming

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label

• An address, or location for the program to jump
  to
• Must end in a colon
• Can be any name, but not a command
• No spaces allowed, use an underline in place of a
  space
• Cant begin with a number

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PAUSE time

• Halts program execution for a number of
  milliseconds (1/1,000 of a second)
• Used to prevent the program from finishing in a
  fraction of a second

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HIGH C.2 and LOW C.2

• Used to trigger the camera
• HIGH activates the relay which is the cameras
  new shutter switch
• Keep HIGH for about 1 second
  (PAUSE 1000)
• LOW turns off the relay
  (camera needs you to release the shutter)

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IF PINC.3 n label

• Monitors the Commit Pin
• Conditional jump, only occurs if condition is
  true
• Prevents flight computer from recording data
  until ready for launch
• n can be either a 0 or a 1
• IF PINC.3 0 then Commit Pin is in place
• IF PINC.3 1 then Commit Pin is removed

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READADC i/o,Bx

• Converts analog sensor voltage to a digital value
• Linear conversion 0V 0 and 5V 255
• Specifies the I/O pin (either C.1 or C.4) to
  digitize
• Specifies the RAM memory to store the result (B0
  to B27)

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Write Bn, x

• Writes a variable from temporary RAM into
  permanent Data Memory
• RAM variable can be B0 to B27
• Data Memory address runs from 0 to 255

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READ x,Bn

• Reads data from permanent Data Memory into
  temporary RAM
• Required to send the data via SERTXD
• Data Memory address runs from 0 to 255
• RAM variable can be B0 to B27

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SERTXD text, Bn

• Writes variable from RAM to the PC
• Writes text (must enclose text in quotes)
• Use the PICAXE Terminal program (F8)
• Set Terminal for 4800 baud

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GOTO label

• Jumps program execution to the label
• Unconditional jump, happens as soon as command is
  executed

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FOR Bn x TO y

• Loop control, makes program repeat itself
• Saves program memory, a short program can be
  repeated many times without writing the program
  many times (maximum of 255 times)
• Bn is the RAM variable that monitors how many
  times the loop of code has been repeated
• x is the starting number
• y is the finishing number

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NEXT

• Placed at the end of the lines of code repeated
  by the FOR command
• Indicates the end of the repeated code
• Easier to read program if the lines of code
  between the FOR and NEXT are indented