Code replacement for irrigation controllers

An irrigation controller comprising:

• a control device including a first microcontroller configured to execute stored irrigation functions using a first set of code;
• and
• a removable plug-in device configured to removably mate with a portion of the irrigation controller such that the removable plug-in device is communicationally coupled to the first microcontroller, wherein the removable plug-in device comprises a memory storing a second set of code to be utilized in a re-flash to replace at least a portion of the first set of code, wherein the removable plug-in device is configured to enable a re-flash of at least the portion of the first set of code allowing a copy of the second set of code to be transferred to the control device to be used in the re-flash as at least part of an overwrite of the at least the portion of the first set of code of the control device;
• wherein the removable plug-in device is assigned an address and comprises a wireless transceiver configured to wirelessly communicate with remote devices, wherein the second set of code is received from a remote device via the wireless transceiver;
• and
• wherein, the removable plug-in device is configured to remain mated with the portion of the irrigation controller and comprises a second microcontroller configured to send and receive data communications to and from the first microcontroller, wherein the first microcontroller is configured to operate in accordance with the second set of code, and wherein the first microcontroller and the second microcontroller are configured to function together during use of the control device.