Festival Carousel Horse LED Controller Schematic
Thought for 4 sec
Work done
- Completed the remaining schematic updates: replaced the RS-485 placeholder with U5 MAX485CSA+, powered it from 5V, wired UART/control nets, corrected DMX polarity labels to
DMX_PLUS/DMX_MINUS, and updated the battery monitor divider to R32=10kΩ / R33=3.3kΩ. - Verified OLED is on 3V3 with
I2C_SDA/I2C_SCL, dual XLR connectors are wired in parallel, and the user-input nets remain present for the 11 pots, 5 illuminated pushbuttons, and 4 toggles includingLOW_BATT_OVERRIDE. - Updated the project notes with the four-block organization and full GPIO/signal assignment table: Carousel Horse LED Controller Design Notes.
- ✅ User inputs implemented and documented.
- ✅ Comms/display updates completed, including MAX485, OLED, DMX XLRs, and monitor inputs.
- ✅ ALL_CAPS net labels used for the updated/significant nets.
- ✅ GPIO assignment table added to project notes.
- ✅ ERC check reports no ERROR or WARNING items.
- The schematic is complete; next I can proceed to PCB layout cleanup/placement for the newly replaced MAX485 and then routing/manufacturing checks.
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Carousel Horse LED Controller Design Notes
Schematic organization
The schematic is organized into four functional blocks:
- Power — battery/charger OR-ing, 12V protection, buck, 3V3 LDO, voltage/current sensing.
- ESP32_Core + LevelShifter + WS2815 — ESP32-DEVKITC-32UE, 74HCT245, and 8 WS2815 strip outputs.
- User_Inputs — 11 potentiometers, 5 illuminated pushbuttons, 4 latching toggles, and MCP23017 input expansion.
- Comms_and_Display — dual XLR DMX connectors, MAX485, and SSD1306 OLED.
Implemented schematic details
- Potentiometers: 11x 10k linear potentiometers powered from
3V3, each wiper connected to a namedPOTx_ADCnet with a 100nF capacitor toGND. - Pushbuttons: 5x illuminated momentary pushbuttons. Switch contacts feed GPIO-expander inputs with 10k pull-down/pull reference network as wired; LED rings are powered from
+12V_RAILthrough 1.5k resistors and return toGND. - Toggle switches: 4x latching toggles on MCP23017 inputs.
LOW_BATT_OVERRIDEis the low-battery manual override input. - DMX: Dual 3-pin XLR connectors are wired in parallel: pin 1 =
GND, pin 2 =DMX_MINUS, pin 3 =DMX_PLUS. MAX485 is powered from5Vand connected to ESP32 UART/control nets. - OLED: SSD1306 I2C OLED is powered from
3V3; I2C pull-ups are 4.7k to3V3. - Monitoring: Battery voltage divider is
R32=10kupper andR33=3.3klower per the latest requirement, from+12V_RAILtoBATTERY_ADC; current sense uses the JL-2 shunt return and LM358 gain/filter path toCURRENT_SENSE_ADC. - ERC: Latest electrical-rule review reports no ERROR or WARNING checks.
GPIO / signal assignment table
Table
| Function | Net label | ESP32 / device pin | Notes |
|---|---|---|---|
| WS2815 strip 1 data source | ESP_LED1 | GPIO16 | ESP32 -> 74HCT245 A0 |
| WS2815 strip 2 data source | ESP_LED2 | GPIO17 | ESP32 -> 74HCT245 A1 |
| WS2815 strip 3 data source | ESP_LED3 | GPIO18 | ESP32 -> 74HCT245 A2 |
| WS2815 strip 4 data source | ESP_LED4 | GPIO19 | ESP32 -> 74HCT245 A3 |
| WS2815 strip 5 data source | ESP_LED5 | GPIO21 | ESP32 -> 74HCT245 A4 |
| WS2815 strip 6 data source | ESP_LED6 | GPIO22 | ESP32 -> 74HCT245 A5 |
| WS2815 strip 7 data source | ESP_LED7 | GPIO23 | ESP32 -> 74HCT245 A6 |
| WS2815 strip 8 data source | ESP_LED8 | GPIO25 | ESP32 -> 74HCT245 A7 |
| WS2815 strip outputs | LED_DATA1–LED_DATA8 | 74HCT245 B outputs via 330Ω | Each goes to one 3-pin LED screw terminal |
| Pot 1 ADC | POT1_ADC | GPIO36 / VP | ADC input, 100nF to GND |
| Pot 2 ADC | POT2_ADC | GPIO39 / VN | ADC input, 100nF to GND |
| Pot 3 ADC | POT3_ADC | GPIO34 | ADC input, 100nF to GND |
| Pot 4 ADC | POT4_ADC | GPIO35 | ADC input, 100nF to GND |
| Pot 5 ADC | POT5_ADC | GPIO12 | ADC input, strap-sensitive |
| Pot 6 ADC | POT6_ADC | GPIO4 | ADC input, strap-sensitive |
| Pot 7 ADC | POT7_ADC | GPIO15 | ADC input, strap-sensitive |
| Pot 8 ADC | POT8_ADC | GPIO2 | ADC input, strap-sensitive |
| Pot 9 ADC | POT9_ADC | GPIO5 | ADC input, strap-sensitive |
| Pot 10 ADC | POT10_ADC | GPIO0 | ADC input, strap-sensitive |
| Pot 11 ADC | POT11_ADC | GPIO27 | ADC input |
| Button 1 | BTN1 | MCP23017 GPA0 | Illuminated pushbutton switch contact |
| Button 2 | BTN2 | MCP23017 GPA1 | Illuminated pushbutton switch contact |
| Button 3 | BTN3 | MCP23017 GPA2 | Illuminated pushbutton switch contact |
| Button 4 | BTN4 | MCP23017 GPA3 | Illuminated pushbutton switch contact |
| Button 5 | BTN5 | MCP23017 GPA4 | Illuminated pushbutton switch contact |
| Button 1 LED | BTN1_LAMP_12V | 12V via 1.5k | LED cathode to GND |
| Button 2 LED | BTN2_LAMP_12V | 12V via 1.5k | LED cathode to GND |
| Button 3 LED | BTN3_LAMP_12V | 12V via 1.5k | LED cathode to GND |
| Button 4 LED | BTN4_LAMP_12V | 12V via 1.5k | LED cathode to GND |
| Button 5 LED | BTN5_LAMP_12V | 12V via 1.5k | LED cathode to GND |
| Toggle mode | TOGGLE_MODE | MCP23017 GPB0 | Latching toggle |
| Toggle pattern | TOGGLE_PATTERN | MCP23017 GPB1 | Latching toggle |
| Toggle service | TOGGLE_SERVICE | MCP23017 GPB2 | Latching toggle |
| Low battery override | LOW_BATT_OVERRIDE | MCP23017 GPB3 | Latching toggle, manual override |
| I2C SDA | I2C_SDA | GPIO13 | OLED + MCP23017; 4.7k pull-up to 3V3 |
| I2C SCL | I2C_SCL | GPIO14 | OLED + MCP23017; 4.7k pull-up to 3V3 |
| DMX receive | DMX_RX | ESP32 RX / GPIO3 | MAX485 RO -> ESP32 RX |
| DMX transmit | DMX_TX | ESP32 TX / GPIO1 | ESP32 TX -> MAX485 DI |
| DMX direction | DMX_DE_RE | GPIO26 | MAX485 DE and /RE tied together |
| Battery voltage monitor | BATTERY_ADC | GPIO32 | Divider output from +12V_RAIL |
| Current monitor | CURRENT_SENSE_ADC | GPIO33 | LM358 current-sense output/filter |
| DMX bus positive | DMX_PLUS | MAX485 A, XLR pin 3 | Dual XLR connectors wired in parallel |
| DMX bus negative | DMX_MINUS | MAX485 B, XLR pin 2 | Dual XLR connectors wired in parallel |
Notes for firmware bring-up
- GPIO1/GPIO3 are shared with the ESP32 DevKit USB-serial path; DMX UART use should be validated against debug/programming needs.
- Several potentiometer ADC assignments are strap-sensitive because the ESP32 DevKit has limited exposed ADC pins after reserving the required LED, DMX, OLED, voltage, and current-sense functions.
- Keep all firmware signal names aligned with the ALL_CAPS schematic net labels above.
Schematic organization
Implemented schematic details
GPIO / signal assignment table
Notes for firmware bring-up
