Cheap ($33 USD), K-type thermocouple (apparently this can be changed in the “secret menu”)

Available from Sure Electronics. Sure sells on eBay too.

The unit I received has two control outputs, SSR (OUT1) and RELAY (OUT2) and is labeled:

Examples of this controller in use:

• Keith used this one in his hotplate project (includes photos of the insides of the controller).
• Make: volume 25 includes a Sous Vide Immersion Cooker based on this controller.
  • The Make article is based on a blog post here.

• Manual - The (incomplete) manual that ships with the unit. local copy
• Another manual that documents some additional options local copy
  • This includes information about the “meter parameter mode” or “secret menu”

The available documentation for this controller is poor. By playing with the configuration settings, I have discovered some useful but undocumented features. If anyone knows of more hidden features, please add them here.

Note: These settings apply to the FK02-VM*AN-NN. I haven't tested them on any other CD101 variants.

These settings can be accessed by holding SET and < at the same time for 3s, then setting Cod to 0000. More information is available in the 2nd user manual given above.

• SL 1 sets the input type, defaults is K-type thermocouple. Chart in 2nd manual listed above.
  • I haven't verified that other inputs actually function correctly, but Scott's Sous Vide cooker uses a PT100 sensor and it apparently works. UPDATE: SL1=1100 setting for PT100 changes the display to include one decimal point. David 23/02/2011
• SL 2 = 0000 sets the unit to display all temperatures in Celsius
• SL 2 = 0001 sets the unit to display all temperatures in Fahrenheit
• SL 6 = 0001 disables OUT2 (the relay output) and stops the audible clicking associated with it
• SL10 = 0001 enable STOP mode (which doesn't appear to work correctly anyway)
• SL10 = 1000 enable ST (Self Tune) mode - makes ST appear in the menus

• The STOP feature doesn't seem to work.
  • Pressing the R/S button for 2 sec results in STOP being shown on the upper display, but the outputs continue to function. According to the documentation, outputs and alarms should be disabled in STOP mode. If anyone knows how to fix this, please let me know. — jeff 01/12/2011 12:53

Photos of CD101 disassembly thanks to Keith Neufeld (with permission) and originally appeared here.