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Rev 2 Built

A project log for IOT the USB Grow Lights

Fix broken 5v grow lights and IOT them in the process.

mulcmumulcmu 07/30/2022 at 02:080 Comments

I built up 4 of the Rev 2 boards.  I've been using up a 5 year old tube of solder paste by adding some fresh flux and mixing it up on the stencil before spreading.  This round turned out a bit thin and spread out a bit too much on some of the pads.  A bunch of tombstones and misaligned SOT-23 after reflow.

The voltage supervisors was still causing some issues.  The 3.3V regulators on 2 of the boards were in the 3.25 range and that wasn't enough to satisfy the supervisor so the ESP was held in reset.  I ended up removing them and boards worked fine, for future builds getting a 3.2V or 3.15V threshold supervisor.

An unpopulated Rev 1 PCB was used to make a generic bed of nails adapter for a programing fixture.  It worked well enough for programming a few by hand.

The replacement grow light was upgraded with a Rev 2 board.  The PCB fit in the alternate style case with one modification to clip a plastic standoff interfering with the ESP shield.  The Rev 2 boards used a 2A poly fuse and this light was built using a 2A barrel jack with corresponding pigtail to connect with the control box.

Lack of LED on the board makes troubleshooting difficult and the user feedback seems to be missing.  The only unused pin is the TX line which could be utilized for some feedback, just not one that is always on and light up a dark room bright.

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