Controleo3 Reflow Profiles

Overview

Controleo3 supports up to 28 profiles. There is a temptation to say "reflow profiles" but the language used to create profiles is so powerful and flexible that it can be used to create complex baking profiles - or even something as simple as open and close the oven door a few times.

The profiles are created on your PC and saved to a SD card. The SD card is scanned by Controleo3 and all profiles are read and stored in the on-board flash memory. The profile can then be selected and used to perform a reflow.

Notes about profiles

  1. Profiles are created on your computer, and saved to a SD card. The SD card is then read by Controleo3 and the profiles stored in on-board flash memory. Once the profiles have been read there is no need to keep the SD card inserted.
  2. The SD card is inserted into Controleo3 upside-down. We hate this too.
  3. The SD card must be formatted to FAT16 or FAT32. NTFS, exFAT or other formats won't work. The SD card supplied with Controleo3 must be reformatted before it can be used.
  4. Profile files must have a TXT file extension (e.g. "LED_PCB.txt")
  5. Profile files can be anywhere on the SD card, including folders and sub-folders. The entire card is searched for TXT files.
  6. Controleo3 reads files, interprets the commands and then stores the profile as a series of tokens. There is a 4K size limit per profile, but since only tokens are saved this corresponds to over 1000 instructions. Most profiles will use 30 to 40 tokens.
  7. Profiles are indexed by the name of the profile so the name must be unique. The profile name comes from the "Name" token inside the file. The SD card filename is irrelevant and not used.
  8. A profile read from the SD card will always overwite one with the same name currently in on-board flash memory.
  9. You are able to delete a profile from on-board flash memory. Wow!
  10. Currently the only way to view the tokens, and ensure the profile from the SD card was interpreted correctly is to run Arduino's Serial Monitor on your PC and connect to Controleo3's USB port. Hopefully a future software update allows this to be done on Controleo3's screen.

If you use Notepad++ you can use the language description here.

Profile language

The language used for profiles was designed to be powerful and flexible, while also making profile files easy to read and understand. The language is interpreted and stored as a sequence of tokens. Controleo3 then uses these tokens to control the behavior of the oven.

In many cases, PID control is desired to ramp up the oven temperature over a fixed period of time. This can be done by using the "ramp temperature" command. However, it is also possible to run the oven in non-PID mode using the "element duty cycle" command and then waiting for a certain period of time or temperature.

Commands

All commands are case-insensitive. You can have multiple commands on one line, or even have a command on one line and its parameters on another. End-of-line is only relevant for comments, and can either be 0xA (line feed), 0xD (carriage return) or any combination of the 2 characters.

You can use either "#" or "//" to add comments to a file. Anything after the start of the comment is ignored, up to the end of the line. You can also have comments at the end of a line, for example "Close door 10 // Close the oven door over 10 seconds".

Commands can be given multiple times in the file. For example, you can specify a "maximum temperature" for each phase of the reflow.

1. Name "name"

This is the name of the profile. It must be unique and is used by Controleo3 to index the profiles. The name of the profile can be at most 31 characters long, and only ASCII-127 characters can be used. The '~' character is translated into the degree symbol, so "Lead-free 250~C" becomes "Lead-free 250°C"

2. Title "title"

This appears in the top-left corner of the screen while the profile is running. The title can be at most 31 characters long, and only ASCII-127 characters can be used. If this command is missing from the profile then "Reflow" will be displayed. However, this command gives you the opportunity to more accurately describe what your profile is doing, like "Curing" or "Firing". This command was introduced in v1.5 of the software.

3. Deviation <max deviation in °C>

This is a safety feature. When the oven is running under PID control, the temperature of the oven may deviate significantly from the required value. This might happen because:

  1. Someone left a lump of lead in the oven so it can't reach temperature
  2. You forgot to close the oven door
  3. One of the elements or relays decided to quit working
  4. The oven is outside, and there's a blizzard
  5. The pizza inside the oven caught fire

The default deviation is 20°C, but you can overwrite this. If the oven temperature ever deviates more than the specified temperature the elements will be turned off, the cooling fan (if any) will be turned on and the oven door opened.

4. Maximum temperature <max temperature in °C>

This is a safety feature. The default is 260°C. If the oven temperature ever exceeds this value the elements will be turned off, the cooling fan (if any) will be turned on and the oven door opened.

5. Initialize timer <time in seconds>

The following 3 commands control the on-screen timer display. By default, the timer starts at zero and increments every second. When using a batch reflow oven, the heating elements take time to heat up initially so it is best to zero-base reflow graph comparisons to a temperature higher than room temperature (like 75°C). You might also want to use the timer to time a certain operation.

The "Initialize timer" command initializes the timer to the specified value, and starts the timer incrementing every second.

6. Start timer

Starts the on-screen timer

7. Stop timer

Stops the on-screen timer

8. Maximum duty <bottom/top/boost>

This command specifies the maximum duty cycle (as a percentage) of the bottom, top and boost heating elements. The default is 100/75/60, but you can overwrite this using this command. This means the bottom element(s) will be on a maximum of 100%, the top 75% and the boost 60%. The maximum duty cycle is always enforced, even if there is a call for more power (see "element duty cycle").

9. Display <string>

The string passed as a parameter to this command will be displayed on the screen. The string must be encapsulated within double-quotes and can be up to 30 characters long.

Note: on Mac's the default is to use curly quotes instead of the standard double quote (character 0x22). You can use System Preferences to change this, or just copy-and-paste a quote from elsewhere in the file

10. Open door <time in seconds>

This will activate the servo to open the oven door over the specified number of seconds.

11. Close door <time in seconds>

This will activate the servo to close the oven door over the specified number of seconds.

12. Door percentage <percent to open> <time in seconds>

Use this command to open the oven door part way. This command was introduced in v1.1 of the software.

13. Bias <bottom/top/boost>

This is only relevant under PID control (ramp temperature). This controls the power distribution and heat direction inside the oven. For example, if the bias is 100/60/20 then the top element will get 60% of the power that the bottom element receives. If the bottom element is at 50% power then the top will receive 50% x 60% = 30%. The boost element in this example will receive 50% x 20% = 10%.

It is often easier to think of these numbers as percentages, and write them that way. But they are just proportions so 100/60/20 can also be written as 10/6/2 or 5/3/1.

14. Convection fan on

Turns on the convection fan if there is one installed.

15. Convection fan off

Turns off the convection fan if there is one installed.

16. Cooling fan on

Turns on the cooling fan if there is one installed.

17. Cooling fan off

Turns off the cooling fan if there is one installed.

18. Ramp temperature <temperature in °C> <time in seconds>

This enables PID control to bring the oven to the specified temperature over the given duration. This command can only be used to increase the temperature of the oven, and cannot control cooling speed.

PID tuning is done automagically during the learning run. PID behavior is typically conservative, favoring undershoot over overshoot. This command is considered complete once the desired temperature is reached, not the duration.

19. Maintain <temperature in °C> for <time in seconds>

This command will keep the oven at the specified temperature for up to 18 hours. The controller will slowly increase the temperature if it is under-temperature, and turn off the elements if it is over. Use the "ramp temperature" command to get the oven close to the desired temperature before using this command. This command was introduced in v1.3 of the software.

20. Element duty cycle <bottom/top/boost>

This command will disable PID control, and modulate the elements at the specified duty cycle. This is typically used at the start of a reflow, when a fast ramp up in temperature is required - but it can be used at any time.

This command is typically followed by a "wait for" or "wait until" command. If you follow this command with a "ramp temperature" command it will be ignored because the oven will be in PID mode!

21. Wait for <time in seconds>

This command adds a delay before the next command is executed

22. Wait until above <temperature in °C>

This command will delay executing the next command until the temperature of the oven rises to the specified temperature. This is typically used after a "element duty cycle" command.

23. Wait until below <temperature in °C>

This command will delay executing the next command until the temperature of the oven falls to the specified temperature. This is typically used after a "element duty cycle" command.

24. User taps screen

The profile will stop running until the user taps the screen. This command was introduced in v1.5 of the software.

25. Show graph <max temperature in °C> <max seconds>

This command will show a graph on the screen, and will graph temperatures up to "max temperature" for as long as "max seconds". The longest plotting duration is 65535 seconds, or 18 hours. This command should be used in conjunction with the "graph divider" and "start plotting" commands. This command was introduced in v1.5 of the software.

26. Graph divider <temperature in °C>

This command adds a horizontal line on the graph at the given temperature. This command was introduced in v1.5 of the software.

27. Start plotting <time in seconds>

Start plotting the time / temperature on the graph, starting at the given time. This command typically follows the "Initialize timer" command, and was introduced in v1.5 of the software.

28. Play beep (v1.1)

Plays a simple beep tone.

29. Play tune

Plays a colorful "reflow done!" tune.

Example profiles

You can download example profile files by clicking here. Use these as a starting point for your paste and oven. These profiles are not tuned to your specific oven so you might need to adjust durations and temperature points to get a good reflow.

The SD card must be formatted using FAT16 or FAT32.

Please reformat the SD card supplied with Controleo3 before using it!