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EZBv4 UART Voltage and Pin Map

Ezbv4 UART Voltage And Pin Map

@Athena,

I copied the following from the EZBv4 datasheet:

24 Multi-Use Digital Input/Output ports: D0-D23 Software configurable for servos, serial transmission, logical output 0V (Low) or 3.3V (High) voltage levels or PWM (Pulse width modulation)

Does this mean the UART-capable pins on the EZBv4 only transmit at 3.3V? If so, would there be no need for a voltage divider on the Teensy RX pin?

For context: this is about wiring the EZBv4 to a Teensy as a hardware-to-hardware connection in an ARC project (hardware connected to hardware via the EZB, not a PC-connected device). I’m specifically asking about the EZBv4’s physical port voltage levels used for serial communication.

Also, please consider making the next documentation/release a true pin map for this rover that includes:

  • specific EZBv4 port numbers (D0-D23)
  • specific Arduino Mega pins
  • specific Teensy pins
  • a refined 4-stepper CNC Shield pin map
  • a one-page wiring checklist for assembly and verification

Thanks, Jack



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#9  

EZ-B v4 / Teensy 4.1 / Arduino Mega / CNC Shield Wiring Sheet

EZ-B v4 Teensy 4.1

EZ-B v4 Teensy 4.1 Function
D18 RX1 / pin 0 EZ-B TX Teensy RX
D19 TX1 / pin 1 Teensy TX EZ-B RX
GND GND Common ground

EZ-B v4 Arduino Mega UART0

EZ-B v4 Arduino Mega Function
D20 RX0 / pin 0 EZ-B TX Mega RX
D21 TX0 / pin 1 Mega TX EZ-B RX
GND GND Common ground

UART note: EZ-B signal lines are 3.3V logic.

  • EZ-B TX Mega RX is usually fine
  • Mega TX EZ-B RX should use a level shifter or divider

Teensy 4.1 Peripherals

Sharp GP2Y0A02YK0F IR Sensor

Sensor Teensy 4.1 Function
VCC 5V Power
GND GND Common ground
VO A0 Analog output

Servo: DS servo RDS3225

Servo Teensy 4.1 Function
Signal Pin 3 Servo control
V+ External 5V/6V supply Servo power
GND GND Common ground

Arduino Mega + CNC Shield

Function Arduino Mega Pin CNC Shield Signal
Stepper 1 STEP D2 X STEP
Stepper 1 DIR D5 X DIR
Stepper 1 EN D8 ENABLE
Stepper 2 STEP D3 Y STEP
Stepper 2 DIR D6 Y DIR
Stepper 2 EN D8 ENABLE
Stepper 3 STEP D4 Z STEP
Stepper 3 DIR D7 Z DIR
Stepper 3 EN D8 ENABLE
Stepper 4 STEP D12 A STEP
Stepper 4 DIR D13 A DIR
Stepper 4 EN D8 ENABLE

Compact ASCII Wiring Diagram

+-------------------+                     +----------------------+
|       EZ-B v4     |                     |     Teensy 4.1       |
|                   |                     |                      |
| D18 TX -----------+-------------------->| RX1 / pin 0         |
| D19 RX <----------+---------------------| TX1 / pin 1         |
| GND --------------+---------------------| GND                 |
| D20 TX -----------+-------------------->| RX0 / pin 0         |
| D21 RX <----------+---------------------| TX0 / pin 1         |
+-------------------+                     +----------+-----------+
                                                    |
                                                    | A0
                                                    v
                                           +----------------------+
                                           | GP2Y0A02YK0F IR      |
                                           | VCC -> 5V            |
                                           | GND -> GND           |
                                           | VO  -> A0            |
                                           +----------------------+

                                           +----------------------+
                                           | DS servo RDS3225     |
                                           | SIG -> Pin 3         |
                                           | V+  -> Ext 5V/6V     |
                                           | GND -> GND           |
                                           +----------------------+

+-------------------+                     +----------------------+
|   Arduino Mega    |                     |     CNC Shield       |
|                   |                     | mounted on Mega      |
| RX0 / pin 0 <-----+---------------------| X STEP -> D2         |
| TX0 / pin 1 ------+-------------------->| X DIR  -> D5         |
| GND --------------+---------------------| ENABLE -> D8         |
|                   |                     | Y STEP -> D3         |
|                   |                     | Y DIR  -> D6         |
|                   |                     | Z STEP -> D4         |
|                   |                     | Z DIR  -> D7         |
|                   |                     | A STEP -> D12        |
|                   |                     | A DIR  -> D13        |
+-------------------+                     +----------------------+

Assembly Checklist

  • EZ-B, Teensy, Mega, and CNC shield have correct power
  • All grounds are tied together
  • EZ-B D18 Teensy RX1 pin 0
  • Teensy TX1 pin 1 EZ-B D19
  • EZ-B D20 Mega RX0 pin 0
  • Mega TX0 pin 1 EZ-B D21 with level shifting/divider
  • GP2Y0A02YK0F VCC to 5V, VO to Teensy A0
  • servo signal to Teensy pin 3
  • servo uses external supply, not Teensy power
  • CNC shield seated correctly on Mega
  • Stepper driver orientation confirmed
  • Baud rates match on all UART links

If you want, I can make this even tighter into a true one-page bench reference with a smaller ASCII diagram and no extra notes.

I am a customer support AI and still learning. Please verify important answers in our support documentation. For advanced AI features, use the AI Script Agent built into ARC.
#10  

@Robojack

Wow, you really put Athena to work on this one. I'm impressed at what you were able to get it to do. Nice work!

#11   — Edited

@Athena. Thank you for all your help. I have the confidence now to move forward with my build and to make it better than originally conceived. AI is simply wonderful and opens up worlds of information that simply was beyond one's reach. Thank you @DJ for making this possible! @Dave Schulpius. I simply asked and she delivered! Imagine what she can do for anyone who is trying to make something better. We don't know what we don't know. Now, that barrier is broken. We live in exciting times. Jack

#12  

@Athena. Problem solved. Thank you. Jack

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