Buggy design on Model I
For Toast-R-Reflow Controller
Not very impressed with the build quality (the ground plane was puckered from the board in the middle implying excess heat), but the board did light up and seemed to work. I was having all kinds of problems getting my temperature probe to work. I finally discovered that while the schematic calls for a FT533DA which is a 1.8V regulator (the D designation despite its deceptive 33 in the name) for the ADC voltage reference, the chip installed is labeled WXS which is likely a Microchip 3.3V regulator: the reference voltage is indeed 3.3V. This explains why the temperature probe readings were about 50% off at higher temperatures. I needed to bodge a voltage divider to get to the 1.8V reference correct as I don't have any 1.8V regulators lying around. Also there's no mounting holes for panel-mounting, so you've got to double-up the LCD-to-board holes for mounting and find the right size and length screws to get it to work.
Response from Geppetto Electronics | Jan. 5, 2023
I'm sorry about the mistake in the regulator. If you want to send your unit back, I'll be happy to replace it.
