Finally got all packed from Thanksgiving and having a good leg day so decided to get down to the shop and work on building up the sensor boards.
Here are the boards as they arrived from OSH park. Went with the minimum order of 3 for now until I am sure no other changes are needed on the boards.
Manually applied the solder paste (direct from the syringe) and placed the first part (LED1).
Boards all placed and ready for the reflow oven.
Boards loaded in my toaster reflow oven ready for heat. Note the wire on the right side is the thermal couple probe inserted in a via on the card. This way I get a accurate card temp over a general air temp in the oven.
Here is my reflow setup left to right I have a over insulated toaster oven, Kearsarge timer, and PID thermal controller. Start to cool down it takes a little under 3 minutes to reflow a oven full of cards. Typically I just crack the door on the oven and let the cards cool naturally.
While waiting for the cards to cool I put together a quick sensor to Pioneer kit adapter. One thing I noted about the kit is the included wires don't make good connections in the headers on the kit. To get a better connection I cut up a 0.1" pin strip and soldered the pins on the end of all the connections.
Cards post reflow but before cleaning. Joints look good and no opens or shorts found. Next a quick scrub with rubbing alcohol to remove the flux and loose solder then a rinse and blow dry and they are ready to go.
Sensor wires attached and sensor ready for use. Long term plan is to coat the sensor in epoxy or silicone to provide strain relief on the cable and protect it from moisture.
And the sensor wired up to the pioneer kit. Did a quick probe of the sensor output to verify functionality with my scope and all looks good so far. Hopefully if I don't have a relapse on the leg I should have about 6 hours to work on it this Friday. Plan is to finish up the frequency counter code and set up a quick data logger so I can collect some real data off one of my plants.