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The following is a description of how the mIoTa boots-up when the power supply is switched on.
At power on, the mIoTa will first check the SD-Card for the Parameters File (params.txt). The parameters file is a human-readable text file that can contain initial boot-up values for any of the mIoTa's O/S and User variables. This is a useful way of manually initializing the Ethernet or Wifi connection settings as well as many other system or user variables.
If the parameter file is found at the root of the SD-Card, then it is loaded and the variables are set accordingly, otherwise the Default values are used.
Next, if an ethernet cable is connected and operating, then the network will be switched to cabled network mode. If no 'live' ethernet connection exists, then the mIoTa will switch into wireless network mode.
During the network connection phase, the mIoTa will load the BASIC program, if it exists on the SD-Card, and the 'Power On Initialization' event will start. This allows the BASIC program to alter the network connection setting if required before the rest of the program begins.
The mIoTa will always default to 'Cabled Network Mode' if a live ethernet cable is connected, even if already connect in wireless mode.
If the O/S Variable E7 (ETH_DHCPEnable) is set to '1' (True) then when cabled mode is initiated, the mIoTa will first attempt to gain an IP address from the networks DHCP Server (usually your Internet Service Providers (ISP's) router). If after a period of retry's, an IP address cannot be gained, then the mIoTa will switch on it's own DHCP server on and become the network controller itself. Acting as the networks DHCP server allows the mIoTa to be directly connected via ethernet and removes the need for another device such as a router or hub.
Wireless mode is initiated if no ethernet connection can be detected. The mIoTa first checks to see if it has a Wifi network connection profile already saved on the SD-Card (uses an encrypted file). If a profile exists then this is loaded. If W0 (WF_SSID) and W1 (WF_SecurityKey) match the SSID and Pass Phrase in the profile, or none have been set, then the mIoTa will continually attempt to connect to the wireless network specified in the profile.
If no wireless profile is available then the mIoTa will check to see if a wireless network SSID has been given in W0 (WF_SSID). If an SSID has been specified then the mIoTa will continually attempt to connect to a wireless network of that name. If the network is found and is password protected then the pass-phrase given in W1 (WF_SecurityKey) will be used. If the pass-phrase is incorrect or doesn't exist then the mIoTa will flash an error via the Network Link LED.
When an external network connection has been made, the mIoTa will attempt to fetch the current time and date from the Internet via a SNTP Server. The mIoTa will use it's default SNTP URL in the O/S Variables unless this has been changed by the user .