Dankdryer improvements

Line 11:

** It's not easy finding a good logic level MOSFET for 3.3v! The RFP30N06LE will only pass about 20% of its rated amperage at 3.3v...but that's more than enough for our needs (the TB6612FNG could only sustain 1.2A, after all). I already had the necessary MOSFET thanks to this [https://www.amazon.com/EEEEE-Transistor-Assortment-Channel-RFP30N06LE cute little set].

* The LM35 is operating in a nasty thermal environment, and on about ten centimeters of poorly-shielded AWG22. Let's give it some bigger boxing gloves. Put a 0.1µF bypass capacitor across its power and ground leads. Put a 75Ω resistor and a 0.22µF capacitor in series between the signal and the wire. These recommendations come directly from the [https://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf datasheet].

===PCB considerations===

===PCB considerations===µ

* We're ditching the Sparkfun NAU7802 breakout board, so we'll need add 2.2kΩ pullups on both I2C lines.

* We're ditching the Sparkfun NAU7802 breakout board, so we'll need add 2.2kΩ pullups on both I2C lines, 0.1µF and 1µF capacitors on VDDA, and 47Ω resistors on VNN1N and VNN1P with a 0.1µF bypass capacitor across them. See the schematic:

[[File:SparkFun-NAU7802.png]]

Dankdryer improvements: Difference between revisions

Dank (talk | contribs)

@@ Line 11: / Line 11: @@
 ** It's not easy finding a good logic level MOSFET for 3.3v! The RFP30N06LE will only pass about 20% of its rated amperage at 3.3v...but that's more than enough for our needs (the TB6612FNG could only sustain 1.2A, after all). I already had the necessary MOSFET thanks to this [https://www.amazon.com/EEEEE-Transistor-Assortment-Channel-RFP30N06LE cute little set].
 * The LM35 is operating in a nasty thermal environment, and on about ten centimeters of poorly-shielded AWG22. Let's give it some bigger boxing gloves. Put a 0.1µF bypass capacitor across its power and ground leads. Put a 75Ω resistor and a 0.22µF capacitor in series between the signal and the wire. These recommendations come directly from the [https://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf datasheet].
-===PCB considerations===
+===PCB considerations===µ
-* We're ditching the Sparkfun NAU7802 breakout board, so we'll need add 2.2kΩ pullups on both I2C lines.
+* We're ditching the Sparkfun NAU7802 breakout board, so we'll need add 2.2kΩ pullups on both I2C lines, 0.1µF and 1µF capacitors on VDDA, and 47Ω resistors on VNN1N and VNN1P with a 0.1µF bypass capacitor across them. See the schematic:
+[[File:SparkFun-NAU7802.png]]