This project seems slightly more ambitious than the Mobile RFID reader 
As this is quite an extensive project comprising of a little over 20 Particle devices and more, I will break this down in ‘Chapters’.
The scope of the entire project - A modified atmosphere and storage system, responsible for the safe storage of roasted coffee Beans in hermetically sealed containers. In addition to storage and Nitrogen blanketing, the system also controls the accurate dispensing and transport of the components needed to make up our coffee recipes.
CHAPTER ONE - FIREFLI Stepper motor and control unit
Render done in Autodesk Fusion 360
This ‘control unit’ will accommodate:
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Opening and closing of two 24V 50mm actuated Ball Valves utilising the onboard Reed Relays.
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Allow for two analog sensor inputs. In this case, monitoring oxygen, temperature and moisture inside tanks.
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Driving a Nema23 stepper motor connected to a 400mm Stainless Steel auger utilising either DRV8825, TMC2208 or TMC5160 stepper driver.
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Accommodate two Load cells determining product level in tank utilising HX711 amplifier.
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Controlling Nitrogen flushing in each tank.
Clever placement of the jumpers on the PCB allows to accommodate either DRV or TCM drivers depending on the current needed for specific stepper motors. The step down buck converter allows me to have a single 24V input to supply enough voltage to the stepper motor and Solenoids valves, yet at the same time, step down to 5V to supply power to the rest of the system.
I have done two versions of this PCB, one for Particle Photon and the other for Particle Argon/Xenon, depending on where it is needed in the system.
Last but not least, some 0603 status LED’s indicating system health and whether sensors and inputs are working as intended. This unit be sending relevant live data to Ubidots dashboard as per my previous post on the RFID reader.
I will update this post with pictures of the actual control unit as soon I receive the enclosures.
Regards,
Friedl.