Hardware errata

Rev 1

R307 needs more clearance from D400
Pins 1 and 12 of U502 need pull-downs
Pin 1 of U501 needs pull-up
D203 reversed polarity
R236 and R234 are swapped
Q301 needs to be NPN, change to BC817
increase R307 -> 3.3Kohm and increase R500 -> 33Kohm
C201: oscillates at 0 and 1nF, stable at 100nF
add clamp diodes to GND on op-amp outputs to ADC when op-amp has negative supply
R214 -> 7.5k
LM339PT is in TSSOP package. Change for SOIC P/N
GDT200 minimum firing voltage is too low
the relay model should be changed to 9001-05-00. 9001-05-02 is an undocumented normally closed variant.
D504 should follow the schematics in its datasheet
R502 should be connected to VCC
R502 -> 240 ohm
C500 -> 1nF
R234 -> 7.5k
Q104 -> DMN3404
R114 -> 470 ohm
R115 -> 4.7k
R227 -> 470 ohm
R228 -> 4.7k
review values of R226 and R113
C100 -> 47pF NP0 AVX, R107 -> 100K, C101 -> 0.1uF
use crystal type recommended by the MCU datasheet
22k FBI current resistor -> 10k?
add connector for OLED display?
enlarge holes to fit M3 screws comfortably
add 15M (TBC) resistor between A and FIL-
power U200 from a small negative voltage instead of GND
review choice of filament flyback output diode
invert LED position so that the Ethernet LED is closest to the connector
invert polarity of LEDs (Ethernet LED polarity cannot be programmed)
Meanwell DC/DC is coupling noise into pA input
change D351 model to MBR1645
add snubber on D351
add heatsink (Seifert-KK633) to D351