Dankdryer improvements

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==Electronics==

* Let's toss the TB6612FNG motor controller. We only need one direction of rotation, so we control the motor with an [https://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf RFP30N06LE] N-channel MOSFET, a [https://www.vishay.com/docs/88525/1n5817.pdf 1N5817] Schottky diode, and a 10K resistor. The n-FET goes on the ground side of the motor, and the diode runs in parallel with the load (i.e. is connected to the motor's two pins). The resistor pulls down the gate lead. This eliminates four net (AIN1, AIN2, STBY, AO2, APWM go away; we add GATE) ~~wires~~ while adding one resistor, a net reduction of seven joints. I'm not certain that it's actually any cheaper, though; it might actually be more expensive.

* Let's toss the TB6612FNG motor controller. We only need one direction of rotation, so we control the motor with an [https://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf RFP30N06LE] N-channel MOSFET, a [https://www.vishay.com/docs/88525/1n5817.pdf 1N5817] Schottky diode, and a 10K resistor. The n-FET goes on the ground side of the motor, and the diode runs in parallel with the load (i.e. is connected to the motor's two pins). The resistor pulls down the gate lead. This eliminates four net wires (AIN1, AIN2, STBY, AO2, APWM go away; we add GATE) while adding one resistor, a net reduction of seven joints. I'm not certain that it's actually any cheaper, though; it might actually be more expensive.

** It's not easy finding a good throughhole logic level MOSFET for 3.3v (surface mount are readily available)! 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.ti.com/lit/ds/symlink/lm35.pdf datasheet]:

Dankdryer improvements: Difference between revisions

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 ==Electronics==
-* Let's toss the TB6612FNG motor controller. We only need one direction of rotation, so we control the motor with an [https://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf RFP30N06LE] N-channel MOSFET, a [https://www.vishay.com/docs/88525/1n5817.pdf 1N5817] Schottky diode, and a 10K resistor. The n-FET goes on the ground side of the motor, and the diode runs in parallel with the load (i.e. is connected to the motor's two pins). The resistor pulls down the gate lead. This eliminates four net (AIN1, AIN2, STBY, AO2, APWM go away; we add GATE) wires while adding one resistor, a net reduction of seven joints. I'm not certain that it's actually any cheaper, though; it might actually be more expensive.
+* Let's toss the TB6612FNG motor controller. We only need one direction of rotation, so we control the motor with an [https://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf RFP30N06LE] N-channel MOSFET, a [https://www.vishay.com/docs/88525/1n5817.pdf 1N5817] Schottky diode, and a 10K resistor. The n-FET goes on the ground side of the motor, and the diode runs in parallel with the load (i.e. is connected to the motor's two pins). The resistor pulls down the gate lead. This eliminates four net wires (AIN1, AIN2, STBY, AO2, APWM go away; we add GATE) while adding one resistor, a net reduction of seven joints. I'm not certain that it's actually any cheaper, though; it might actually be more expensive.
 ** It's not easy finding a good throughhole logic level MOSFET for 3.3v (surface mount are readily available)! 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.ti.com/lit/ds/symlink/lm35.pdf datasheet]: