I am developing a zigbee based monitoring system for grain storage in agriculture (grain bins / tanks). Where possible, I'll be deploying off the shelf electronics. There is one use case where I cannot fit an ideal off the shelf solution. I'll be monitoring various temperature and moisture detection cables for grain storage. These temp and RH cables deploy Thermocouples and one-wire digital temperature sensors as well as digital relative humidity sensors. I need to have a PCB designed that is capable of reading these types of sensors, as required. the concept is to have one single board capable of reading up to 18 thermocouples as well as at least 2 channels dedicated to the digital temperature and humidity sensors (this number may change as I find more details on these sensors). The readings are not required constantly, (sensor sampling is once per 15min.) so intelligent "switching" of the thermocouple inputs could be deployed if it is a cost savings measure.
The board needs to have provisions for a zigbee pro RF module so as to work on a mesh network featuring a typical zb mesh coordinator.
The board will be mounted on top of the grain storage vessel, so to be a truly wireless solution, the PCB must either be powered by a long life battery (7 years minimum) or either powered or recharged by a solar cell.
Some optional connections should be available for alternative installations, such as alternate 12V power connection (when solar isn't available), RS485 2 wire comms (in case zigbee isn't approved for use)
All field wiring connections to the PCB need to be by screw type terminal blocks that are easily wired
Form factor (foot print) needs to be as small as possible, but still facilitate the desired connectors for ease of field wiring.
Firmware should convert the raw input signals to meaningful values (hexidecimal or integer perhaps) as to be sent via string over zigbee. It may be necessary to provide for a calibration of some kind for accuracy.
My expectations would be for a full design with a complete data packet with drawings, gerbers, etc. all available so that board could be easily manufactured anywhere with no re-design necessary.
Candidates that cannot fulfill initial prototypes and pre-production units need not bid. Bidders that can also fulfill small batch contract manufacturing of final product a HUGE plus.
COGS target for final product would be <$60USD without zigbee module installed.
More Details available upon request.
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I'm have more thant 3 years of embedded wireless experience software design and more than 6 years of hardware design ! For future more info pleas check your PM!
Hello, We are an electronic product design company offering solutions & services. We design both - hardware & software. We can help you finish this project. Samir