AstroCore Board — Setup & Wiring Guide
Complete installation reference for the AstroCore Standard and Pro R2 Head & Audio Control Boards
What's Included
R2 Head & Audio Control PCB (Fully Assembled)
- Integrated Arduino Nano
- Integrated DFPlayer Mini audio module
- Pre-flashed firmware
- Speaker JST output
- CH5 Servo signal output header (Pro also includes CH4)
- CH3/CH5 receiver input header (Pro also includes CH4)
- No soldering required on the board itself
💾 Preloaded Micro SD Card
- Installed and ready to run
- Startup / mode-change sound configured
- Sound library preloaded
- Properly formatted for DFPlayer compatibility
🔌 JST Speaker Connector
- 2-pin JST plug
- For replacing your existing speaker connector
- Direct plug-and-play into the board
- Simply remove your current speaker connector and install this one
🔗 Dupont Jumper Wires
Included to simplify signal and low-current connections:
- Male-to-male Dupont connectors
- Female-to-female Dupont connectors
- For receiver signal connections, servo signal lead, and low-voltage signal wiring
🔥 Heat Shrink Wire Connectors
- Insulated heat shrink butt connectors
- For secure, vibration-resistant wiring
- Ideal for 5V power connections
- Crimp → heat → sealed connection
🔌 18 AWG Power Wire (16 inches)
- 16 inches of 18 AWG wire
- Intended for 5V buck → PCB power connection
- Suitable for up to ~3–5A loads
- Provides proper gauge for clean, stable 5V delivery
🛠 What You Will Need (Not Included)
- 5V buck converter (3A minimum recommended) Buy on Amazon ↗
- RC receiver/transmitter — HOTRC DS-650 recommended Buy on Amazon ↗
- 270-degree servo — upgraded metal gear servo recommended Buy on Amazon ↗
- R2 main battery (7.4–12V system) or other main power supply
- Basic wiring tools (crimper, heat source, wire stripper)
System Overview
This is the preferred, stable wiring method for clean, reliable operation:
- ◆Main battery (7.4–12V typical)
- ◆5V Buck converter — powers PCB logic + DFPlayer
- ◆Receiver powers the servo via its built-in BEC
- ◆All grounds must be common
Wiring Steps
Powering the PCB
Connect your 5V buck converter output to the PCB power pins. Adjust the buck output to exactly 5.0V with a multimeter before connecting.
| PCB Pin | Connect To |
|---|---|
| 5V (+) | 5V Buck Output |
| GND (−) | Buck Ground |
Buck requirements: 5.0V regulated output, 3A minimum. You can also power the board via USB-A to USB-C cable.
Channel 3 Receiver Wiring
| Receiver Wire | Connect To |
|---|---|
| Signal | PCB CH3 Signal Pin |
| Ground | PCB 5V Negative (GND) |
Do NOT connect receiver +5V to PCB. Only connect Signal and Ground. This ensures a proper signal reference.
Servo Wiring (Powered from Receiver)
The servo should be powered directly from the receiver, not the PCB.
| Servo Wire | Connect To |
|---|---|
| Signal | PCB CH5 Signal Pin |
| Red | Receiver +5V |
| Black/Brown | Receiver GND |
Most receivers have a built-in BEC from the ESC supplying 5–6V. This keeps servo load off the PCB and prevents DFPlayer resets when the head moves.
Speaker Wiring
Install the included JST connector and plug directly into the PCB.
| Speaker | PCB |
|---|---|
| + | SPK+ |
| − | SPK− |
Do not connect to an external amplifier, receiver, or ESC. The DFPlayer has its own amplifier.
Grounding — Very Important
The following must all share a common ground:
- Battery negative
- Buck converter ground
- PCB GND
- Receiver GND
- Servo ground (via receiver)
If receiver ground is not tied to PCB ground, the PWM signal will not behave correctly.
Final Install Checklist
- Buck set to 5.0V
- PCB powered from 5V (not VIN) or USB
- Receiver CH3 signal connected
- Receiver CH3 ground → PCB GND
- Servo powered from receiver
- All grounds common
- SD card inserted
- Speaker JST seated
HOTRC DS-650 Transmitter Setup
These settings ensure proper CH3 button detection, reliable double-click and long-press behavior, clean servo response, and no false triggering.
| Channel | Used For |
|---|---|
| CH3 | Sound trigger + mode control |
| CH4 | Additional control channel Pro Only |
| CH5 | Head movement (left/right buttons mixed) |
Set CH3, CH4, CH5, and CH6 to "NORMAL"
This is the most important setting. Power on transmitter → Enter Menu → Navigate to BUTTON TYPE → Find CH3, CH4, CH5, and CH6 → Set all to NORMAL.
AstroCore Pro only: Also set CH4 to NORMAL. CH4 provides an additional control channel available exclusively on the Pro board.
Do NOT use: Toggle, Latch, 2P / 3P switch modes. If CH3, CH5, and CH6 are not set to NORMAL — double-click won't work, long press won't trigger personality mode, sounds may behave unpredictably.
End Point Adjustment (EPA)
Go to EPA and set the following to ensure the board sees the full PWM range:
| Channel | Left | Right |
|---|---|---|
| CH3 | 100% | 100% |
| CH4 Pro | 100% | 100% |
| CH5 | 100% | 100% |
| CH6 | 100% | 100% |
Center All Trims
Go to trim settings and verify CH3 trim = 0 and CH5 trim = 0.
If trims are not centered: head may drift, mode detection may fail, servo may move slowly on its own.
Button Mixing (If Using Two Buttons for Head)
If CH5 and CH6 buttons are being combined, go to MIX and set:
- Master: CH6
- Slave: CH5
- Rate: 100%
- Switch: ON
Result: CH5 button → rotate left | CH6 button → rotate right
Functional Test
With R2 powered, verify the following:
| Action | Expected Result |
|---|---|
| Neutral | Head stays still |
| Hold CH5 | Smooth left rotation |
| Hold CH6 | Smooth right rotation |
| Double click CH5/CH6 | Return to center |
| Single click CH3 | Sound plays |
| Double click CH3 | Personality mode activates |
| Long press CH3 | Change volume level (manual mode only — persists in personality mode) |
Common DS-650 Mistakes
| Problem | Likely Cause |
|---|---|
| Mode won't switch | CH3 not set to NORMAL |
| Double click doesn't work | CH3 in toggle mode |
| Head drifts | Trim not centered |
| Random sound triggers | EPA too low |
Final Settings Summary
| Setting | Value |
|---|---|
| CH3 Mode | NORMAL |
| CH3 EPA | 100% |
| CH4 Mode (Pro only) | NORMAL |
| CH4 EPA (Pro only) | 100% |
| CH5 Mode | NORMAL |
| CH5 EPA | 100% |
| CH6 Mode | NORMAL |
| CH6 EPA | 100% |
| Trims | Centered (0) |
| Mixing (if used) | CH6 → CH5 @ 100% |
Important Notes
Battery rundown warning: Be careful of letting your battery run down to dead while in personality mode. There is a chance that the MicroSD card can become corrupted or even destroyed if it is in the process of playing when the battery dies.
Flashing new firmware: In order to flash new firmware to the AstroCore Standard Board, the Arduino Nano must be removed from the board first. Simply pull the Nano out of the board headers with some gentle force. This step is not necessary on the AstroCore Pro.
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