โฐ Menu
๐ Overview
0. THE BINDING CONSTRAINT โ READ THIS FIRST
1. PROJECT OVERVIEW
2. HARDWARE โ ALREADY OWNED (No Cost)
3. CARPUTER โ HARDWARE TO PURCHASE
4. SYSTEM ARCHITECTURE โ THREE TIERS
5. POWER ARCHITECTURE (the keystone)
6. ESP32 NODE NETWORK (Tier 0)
7. CAMERA SYSTEM + NVR
8. CAN BUS INTEGRATION
9. SOFTWARE STACK
10. THERMAL MANAGEMENT
11. HOME RAG SERVER (HP Z440 #1)
12. OFF-GRID MESH + REMOTE ACCESS (Phase 2/3)
13. PENDING ACTIONS
14. PHASED ROADMAP
15. COST SUMMARY
16. ARCHITECTURE AT A GLANCE
17. MASTER PARTS LIST (BOM) (rev 3.43)
โฃ Wire Diagrams
2-switch panel โ DMWD momentary halo-LED on Modbus IO
๏ผ
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Fit
100%
wheel / pinch = zoom ยท drag = pan
switch_panel_2sw
2014 RAM 1500 Carputer โ SWITCH PANEL, 2x DMWD 12mm momentary halo-LED buttons (Rock + Fog) on the Modbus IO 8CH
Each switch = 4 pins (NO + COM contact, LED+ + LED-). Contact -> a DI (signal only). LED -> a DO (Waveshare drives it = shows true state).
LED is 12-24V with a BUILT-IN resistor: LED+ to 12V, LED- to DO, NO external resistor. Verify pin polarity with a meter (markings are tiny).
LEGEND: blue = contact->DI ยท green = LED- ->DO (sink) ยท red = +12V ยท black = GND ยท magenta = RS485 ยท purple dashed = DO->relay
sw1
SWITCH 1 โ ROCK (DMWD 12mm momentary)
pin NO
pin COM
pin LED+
pin LED-
gnd
GND rail (panel)
sw1:com->gnd
COM->GND
mod
Modbus RTU IO 8CH @ PANEL (SKU 26244) โ RS485 slave addr 2
DI1 (rock btn)
DI2 (fog btn)
DO1 (rock LED)
DO2 (fog LED)
V+ 7-36V
GND
RS485 A
RS485 B
sw1:no->mod:di1
NO->DI1 (24 AWG)
sw1:lm->mod:do1
LED- ->DO1 (sinks when ON)
sw2
SWITCH 2 โ FOG (DMWD 12mm momentary)
pin NO
pin COM
pin LED+
pin LED-
sw2:com->gnd
sw2:no->mod:di2
NO->DI2 (24 AWG)
sw2:lm->mod:do2
LED- ->DO2
v12
+12V rail (panel)
fused ~1-2A at the house bus
v12->sw1:lp
12V->LED+
v12->sw2:lp
v12->mod:v
module power
gnd->mod:g
ctrl
Waveshare ESP32-S3 8DI-8DO โ RS485 MASTER
holds rock + fog STATE (source of truth)
RS485 A
RS485 B
DO rock
DO fog
mod:a->ctrl:a
RS485 A (Cat5 pair1)
mod:b->ctrl:b
RS485 B
r_rock
Bosch relay (rock)
relay/fuse box
ctrl:rk->r_rock
DO trigger
r_fog
Bosch relay (fog)
relay/fuse box
ctrl:fg->r_fog
DO trigger
note
WIRING FOR 2 SWITCHES
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Panel jumpers (switch <-> module): 22-24 AWG (solid Cat5 strands fine) โ signal/LED only, mA.
Per switch: NO->DIx, COM->GND rail, LED+->12V rail, LED- ->DOx. Share the 12V + GND rails.
Conductors used on the module: 2 DI + 2 DO + V+ + GND (room for 6 more switches).
ONE cable home (module -> Waveshare): solid Cat5 โ
pair1 = RS485 A/B ยท pair2 = 12V + GND ยท 2 spare pairs.
120R termination at each bus end only if the run is long/fast.
SHOPPING (2 switches):
2x DMWD 12mm momentary halo-LED (buy MOMENTARY 5-pack)
1x Modbus RTU IO 8CH (handles up to 8 switches)
panel 12V tap + 1-2A inline fuse ยท 2x WAGO/term blocks (12V + GND rails)
1x solid Cat5 home ยท ferrules for screw terminals ยท (2x 120R if long bus)
LED draw ~15-20mA each โ the 500mA DO sinks it easily.
Dash hole = 12mm (1/2"). Debounce the buttons in ESPHome.
rock
ROCK LIGHTS (house 12V, fused)
r_rock->rock
switched + fused
fog
FOG LIGHTS (house 12V, fused)
r_fog->fog
switched + fused
house
+12V always-on house bus
house->v12
tap + 1-2A fuse
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