Oven Temperature Checker - 2nd generation

🔲The original Spacerlabs "Oven Temperature Checker - OTC" appeared on this blog on📅 6 December 2021; but it's development actually began in 📅September 2017. To recap, it's purpose is to measure the air temperature🌡 of the internal cavity of a domestic oven ( non microwave ) to compare with the user set 🌡temperature. This 📮post describes the next generation OTC, and the differences. Many features are, however, retained; for example 2.4GHz BluetoothⓇ wireless 🛜connectivity ( using Bluetooth Low Energy - BLE*) is still used.

The OTC now has a custom 3-D printed case compatible with a terminated ( plug-in ) or unterminated ( hardwired ) Type-K thermocouple. The OTC is powered from an external power source, e.g., power bank, via the micro-usb socket.

Custom case, any colour possible, usb socket on rear, note thermocouple inputs

There is no integral display. The User Interface ( UI ) is the SpacerLabs custom app "OTC_Ui_v1.x" for a BluetoothⓇ enabled Android device. The OTC functions as a BluetoothⓇ server, advertising itself as "SPACERLABS_OTC". Connecting to the server with a paired BluetoothⓇ client device, ( e.g. smart phone having the app installed ), enables the OTC ready for use.

App icon attributed to 'Freepik'

App screen showing a completed measurement run

The App displays the version of the software uploaded to the OTC, real time 🕖clock ( RTC ), status of BluetoothⓇ connection, and received signal 🛜strength indication ( RSSI ) of the BluetoothⓇ signal. A pop-up ⚠alert appears if the 🛜signal is too weak. A measurement cycle, maximum duration ⏲10 minutes, can be started, paused or cleared by tapping the appropriate button. A 🌡temperature measurement is made every ⏲second and plotted. Instantaneous oven 🌡temperature, OTC 🌡temperature, elapsed ⏲time and average oven🌡 temperature over time are numerically displayed. The oven 🌡temperature, up to 240C, is plotted 📈against🕰 time. Any thermocouple faults which might occur are ⚠flagged; OC (open circuit), SCV (short to volts) & SCG (short to ground). Temperature measurements in serial form, data rate 115200Baud, can be accessed by connecting a pc running terminal emulation software to the micro-usb socket.🔳

 

The OTC 📖User Guide can be downloaded 🔗here.

*BLE is the low power variant of classic BluetoothⓇ.