HF11 – 2 Wire RTD Simulator for PT1000


Hui Gardens HF11 2 wire RTD simulator for PT1000 was made to be used as a calibration standard for the Hui Gardens HF3 WiFi RTD Meat Smoker Temperature Transmitter. Coarse (10kΩ) and fine (1kΩ) adjustment via 10 turn potentiometers allow precise setting of resistance value. Since there are no graduated steppings like a traditional decade box, it does not require calibration and is as accurate as the multimeter being used to characterize it.

The banana plug connectors are spaced such that the fancy two conductor leads can be used. Connect the two sets of banana plug connectors to use them together or disconnect to use separately.


This working prototype had been superceded by the Hui Gardens HFX electrical test set

HF6 – 2W USB Powered Amplified Speaker


Hui Gardens HF6 2W USB powered amplified speaker was designed to provide better sound than what comes out of a laptop computer. It is small and fits into a backpack side pocket without issue. The HF6 is powered by a LM386 and features bass boost along with gain and volume adjust. There is even room in the Pelican 1010 case lid to store an aux cable and USB power cable. Hui Gardens HF6 can be powered by any 5VDC source including the USB port on a laptop computer or wall charger.

HF5 – Timing Box


Hui Gardens HF5 timing standard was made to be fairly universal and can act as a transducer that triggers based on the input contacts being closed. The HF5 outputs 5VDC when the trigger input is closed or if the push button is pressed. HF5 is powered by an Arduino Nano and the Arduino micros() library function claims resolution down to 4us. Protected by a Nanuk 903, the HF5 can withstand transport.

Thanks to the 5VDC output, the Hui Gardens HF5 can be used to trigger a frequency counter. Aside from the 5VDC output, the HF5 also has NO (normally open) and NC (normally closed) banana jacks triggered by the same inputs. The HF5 is powered by a 4x AA external battery pack and features a backlit 16×2 LCD display which displays current relay position and timing.