Outdoor Meshtastic Soil Sensor Prototype

I need two simple yet reliable prototype nodes that can sit outdoors, wake up at a configurable interval, pull a register line from a Modbus-compatible soil probe, and push that reading through a Meshtastic link... (Budget: $750 - $1500 USD, Jobs: Arduino, Bash, Circuit Design, Embedded Systems, JSON, Linux, Microcontroller, MySQL, Python, Software Architecture)