Serial_Servo_Pico_HAT_Software

The Pico Serial Servo HAT is a versatile and compact HAT for Pico/Pico W microcontroller with dual power options, two serial servo connectors, and two programmable buttons. It features a 1.14” TFT display for status updates, a power LED indicator, and supports simultaneous multi-servo control, making it ideal for projects requiring precise coordination and multiple servos with minimal wiring like Robotic Arm Control, CNC machine and Automation.

This github provides getting started instructions for Serial Servo Pico HAT.

Features

Pico Serial Servo compatible Hat for Pico and Pico W board
TFT 1.14” display for user interactions.
Two slots to connect Serial Servo Motors, and easily cascade servo to connect more motors. Allows controlling 1-253 serial servos at the same time*
Two Programmable Buttons to add additional controls to project
Header 2.54” and DC jack options to connect 6-8.4V adapter with onboard regulator
Power status LED to indicate board power.
Compact and space-saving design
Compatible Servo Motors =>
- SB-SS023 - For Lightweight Projects
- SB-SS15 - For Heavier Applications
- Servo Motor Key Features:
  - Real-Time Position, Load, Temperature, Speed, and Voltage feedback.
  - Servo/Motor Mode Switchable
  - High Precision And Large Torque
  - ID Range 1~253
  - 38400 bps ~ 1Mbps (1Mbps by default)

*NOTE: Avoid Connecting More Than 6 Servos At A Time, Not Recommended Due To High Current Demand By Servos.

For more details about Serial Servo Motor checkout Manual.

Specification:

Microcontroller: Supports Raspberry Pi Pico/Pico W
Board Supply Voltage: 5V
Operating Pin Voltage: 3.3V
Operating Servo voltage: 6~8.4V
Display Size: 1.14”
Display Resolution : 240x320 pixels
Display Driver: ST7789
Display Appearance: RGB, 65K/262K
Temperature Range: -20°C ~ +70°C

Getting Started with Serial Servo Pico HAT

Pinout

(1) Power Status LED
(2) Header 2.54” input (6~8.4V DC)
(3) DC Jack input (6~8.4V DC)
(4) & (5) Programmable Buttons
(6) & (7) Serial Servo Connectors
(8) TFT 1.14” Display
(9) Pico Header Support

Interfacing Details

When HAT is connected with Pico/Pico W following pins interfaced with onboard hardware components,

Serial Servo Bus Pins:
- Servo connector having +ve[6~8.4VDC], -ve[GND] and Signal pin.
- Serial Servo Signal pins breakout into UART RXD and TXD to connect with PICO UART pins,
  
  Pico Servo Description
  
  TXD0/GPIO43 Servo Bus RXD UART communication pin
  
  RXD0/GPIO44 Servo Bus TXD UART communication pin

Pico	Servo	Description
TXD0/GPIO43	Servo Bus RXD	UART communication pin
RXD0/GPIO44	Servo Bus TXD	UART communication pin

Display interfacing with Pico

Pico	Display	Function
GP10	LCD_CLK	Clock pin of SPI interface for Display
GP11	LCD_DIN	MOSI (Master OUT Slave IN) pin of SPI interface
GP09	LCD_CS	Chip Select pin of SPI interface
GP08	LCD_DC	Data/Command (MISO) pin of SPI interface
GP12	LCD_RST	Display Reset pin
GP13	BL	Backlight of display

Buttons Interfacing

Pico Hardware Function

GP14 BT1 Programmable Button

GP15 BT2 Programmable Button

Pico	Hardware	Function
GP14	BT1	Programmable Button
GP15	BT2	Programmable Button

1. How to Install Boot Firmware in Pico/Pico W of HAT

If you already have MicroPython firmware with the inbuilt ST7789 module, then you can skip this step and jump to step 2 for trying demo codes.
In case, you need to add MicroPython firmware in Pico of HAT. First, you need to Press and Hold the boot button on pico W, and then, without releasing the button, connect it to PC/laptop using micro USB cable. Check below image for reference,
Now your device is in boot mode, and you will see a new mass storage device named "RPI-RP2" as shown in the below figure.
Download the MicroPython firmware file provided in this repo above as "firmware.uf2". Drag and drop this firmware.uf2 file onto the RPI-RP2 volume.

2. Running First Program

Download Thonny IDE from Download link as per your OS and install it.
Download this github which contains various examples and open anyone of example in Thonny.
Now we have Thonny IDE application and github example codes, Connect hardware to laptop/PC. Open any example code in Thonny IDE. Then select micropython device at the bottom right with a suitable COM port, as shown in the below figure. You might get a different COM port.
Make sure to save SerialServo.py library file to device to avoid any execution error.
Once everything all set, with any demo code open click on green play button to test program.
For standalone execution save script into Pico as main.py,

Try out below provided reference example demo codes and modify to build your own application codes.