Teensyduino code for sampling from a flowmeter and communicating via CAN-bus Simply have one teensy programmed with a code in can_master, which controls the flowmeter, and the other teensy with flowmeter_v0 code. If you wire them according to the instruction in https://www.mikrocontroller.net/attachment/28831/siemens_AP2921.pdf , you should be able to see the reset and sampling rate changes through the Serial Monitor of master teensy.