post_box_usb: add two pulldown resistors for target_5V_ext

google · Jul 20, 2021 · d0539b4 · d0539b4
1 parent 9e91748
commit d0539b4
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Showing 8 changed files with 1,505 additions and 1,383 deletions.
diff --git a/post_box_usb/pcb/bill_of_materials.txt b/post_box_usb/pcb/bill_of_materials.txt
@@ -46,6 +46,8 @@ R2	1k	Resistor 0805: 1k	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder
 R7	1k	Resistor 0805: 1k	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17513
 R8	1k	Resistor 0805: 1k	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17513
 R14	1k	Resistor 0805: 1k	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17513
+R24	1k	Resistor 0805: 1k	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17513
+R25	1k	Resistor 0805: 1k	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17513
 R6	2k2	Resistor 0805: 2k2	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17520
 R3	330R	Resistor 0805: 330R	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17630
 R13	330R	Resistor 0805: 330R	Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C17630

diff --git a/post_box_usb/pcb/pcb-back.png b/post_box_usb/pcb/pcb-back.png
diff --git a/post_box_usb/pcb/pcb-front.png b/post_box_usb/pcb/pcb-front.png
diff --git a/post_box_usb/pcb/post_box_usb.kicad_pcb b/post_box_usb/pcb/post_box_usb.kicad_pcb
diff --git a/post_box_usb/pcb/post_box_usb.net b/post_box_usb/pcb/post_box_usb.net
@@ -52,6 +52,8 @@
     (comp (ref R21) (value 330R) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
     (comp (ref R22) (value 330R) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
     (comp (ref R23) (value 100k) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
+    (comp (ref R24) (value 1k) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
+    (comp (ref R25) (value 1k) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
     (comp (ref R3) (value 330R) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
     (comp (ref R4) (value 4k7) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
     (comp (ref R5) (value 4k7) (footprint Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder))
@@ -438,7 +440,9 @@
       (node (ref L5) (pin 1))
       (node (ref POST) (pin 1))
       (node (ref TEST) (pin 1))
-      (node (ref U2) (pin 3)))
+      (node (ref U2) (pin 3))
+      (node (ref R24) (pin 1))
+      (node (ref R25) (pin 1)))
     (net (code 87) (name target_5V_r) (node (ref HSBUF) (pin 9)) (node (ref R14) (pin 2)))
     (net (code 88) (name target_D0) (node (ref POST) (pin 2)) (node (ref TEST) (pin 2)) (node (ref R6) (pin 1)))
     (net
@@ -454,6 +458,8 @@
       (node (ref POST) (pin 6))
       (node (ref TEST) (pin 6))
       (node (ref U2) (pin 1))
+      (node (ref R24) (pin 2))
+      (node (ref R25) (pin 2))
       (node (ref R18) (pin 1))
       (node (ref R19) (pin 1))
       (node (ref R20) (pin 1)))

diff --git a/post_box_usb/pcb/post_box_usb.py b/post_box_usb/pcb/post_box_usb.py
@@ -868,6 +868,13 @@
 # target_5V_fuse = myelin_kicad_pcb.R0805("PTC", "target_5V_unfused", "target_5V_fused", ref="F2")
 # target_GND_fuse = myelin_kicad_pcb.R0805("PTC", "target_GND_unfused", "target_GND", ref="F1")
 
+# Pulldown on target_5V_ext so L4 doesn't light due to parasitic current through R7 and R8.
+# Split into two to be extra careful about heat dissipation.
+target_5V_ext_pulldowns = [
+    myelin_kicad_pcb.R0805("1k", "target_5V_ext", "target_GND", ref="R24"),
+    myelin_kicad_pcb.R0805("1k", "target_5V_ext", "target_GND", ref="R25"),
+]
+
 target_5V_protection = myelin_kicad_pcb.R0805("1k", "target_5V", "target_5V_r", ref="R14")  # for LCX input
 
 target_D0_pullup = myelin_kicad_pcb.R0805("2k2", "target_D0", "target_5V", ref="R6")

diff --git a/post_box_usb/pcb/post_box_usb_jlc_pcba_bom.csv b/post_box_usb/pcb/post_box_usb_jlc_pcba_bom.csv
@@ -13,7 +13,7 @@ P-MOSFET,U2,Package_TO_SOT_SMD:SOT-23,C75561
 Resistor 0805: 0R,R20,Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17477
 Resistor 0805: 100k,R23,Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17407
 Resistor 0805: 10k,"R1,R9,R10,R11",Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17414
-Resistor 0805: 1k,"R2,R7,R8,R14",Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17513
+Resistor 0805: 1k,"R2,R7,R8,R14,R24,R25",Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17513
 Resistor 0805: 2k2,R6,Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17520
 Resistor 0805: 330R,"R3,R13,R21,R22",Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17630
 Resistor 0805: 4k7,"R4,R5",Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder,C17673

diff --git a/post_box_usb/pcb/readable_bill_of_materials.txt b/post_box_usb/pcb/readable_bill_of_materials.txt
@@ -236,6 +236,16 @@ R14
 - Description: Resistor 0805: 1k
 - KiCad package: Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder
 
+R24
+- Value: 1k
+- Description: Resistor 0805: 1k
+- KiCad package: Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder
+
+R25
+- Value: 1k
+- Description: Resistor 0805: 1k
+- KiCad package: Resistor_SMD:R_0805_2012Metric_Pad1.15x1.40mm_HandSolder
+
 R6
 - Value: 2k2
 - Description: Resistor 0805: 2k2