- 8-bit microcontroller with internal RC oscillator.
- Superregenerative amplitude modulated receiver.
- High mechanical shock tolerance.
- Servo driver (two pre-set end-points).
- In-system programming capability.
- 25.4×50.8mm (1×2″).
- 4-7V battery powered.
Although the mounting technique employed for the above board is not shown, the product is able to withstand extremes of force and widely varying temperatures. The unit must function in the rugged environment of logging in British Columbia (and the rest of the world), year ’round.
On power-up, the processor will unconditionally rotate a servo to a “set” position, whereupon a standby state is entered awaiting incoming manchester coded data. On reception of the correct 8-bit code, the processor rotates the servo to a “release” position and powers down.
Although superregeneration is an older form of RF demodulation, this type has distinct advantages; most notably, quartz-based crystals, oscillators and filters are not required. Quartz is a robust material, however when used for frequency generation, mounting of the material is inherently fragile.
The receiver is mounted in a manner that allows its enclosure to tolerate forces of up to 10,000 Gs. This is one of the most remarkable achievements of the product.
Durability testing was performed by repeated six meter drops onto a two inch thick steel plate. The bar was set at a minimum of 25 impacts without incident. The availability of only a few prototype radios for testing meant that the same one was used for multiple drop tests. The beta unit survived well over 100 impacts, and continued to function to the end of testing.
This product is a component of a larger system used in the forestry industry. General inquiries can be directed to Johnson Industries, Logging Division.
Inquiries regarding designing and programming with microcontrollers, superregenerative RF receivers, and working with servo motors can be directed to J-Tech Engineering. Please see the company info page for contact information.