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First Power-Up and Testing

Hooking up the Power Supply

The ByteCradle board requires a 5V power supply capable of delivering at least 500 mA of current. Power is supplied through a USB-B connector. The ByteCradle does not have any on-board power regulation. It is critical to use a reliable and regulated 5V power source to avoid damaging the board. Recommended options include:

  • A direct connection to a computer USB port
  • A certified USB wall adapter rated for 5V output

Power Supply Safety

Avoid using low-quality or unregulated power adapters, as unstable voltages can cause erratic behavior or permanent damage to the board.

Power-Up Sequence

Before powering up the board, make sure the serial communication cable (see next section) is connected and a serial port has been opened on your computer. This ensures you will see the header information that the board outputs upon boot. If you power on the board before setting up the serial connection, you can still communicate with it, but you will miss the initial startup messages. In that case, simply press the reset button on the board to perform a cold boot and re-trigger the startup sequence.

Setting Up Serial Communication

Communication with the ByteCradle platform is handled via a standard RS232 serial interface, implemented using the onboard 65C51 ACIA (Asynchronous Communications Interface Adapter) and a MAX232 line driver. This setup ensures reliable and straightforward serial communication, supporting both TTL and RS232 voltage levels.

The default communication settings are:

  • Baud Rate: 115200
  • Data Bits: 8
  • Parity: None
  • Stop Bits: 1

(commonly referred to as 8N1 configuration).

Several tools are available to interface with the board over RS232:

Finding the correct serial port

  • On Windows: Open Device Manager and look under Ports (COM & LPT). Your device will appear as something like COM3, COM4, etc.
  • On MacOS: Use the command ls /dev/tty.* in Terminal. Look for entries like /dev/tty.usbserial-XXXXX.
  • On Linux: Use ls /dev/ttyUSB* or ls /dev/ttyACM* depending on your USB-to-serial adapter. Common examples include /dev/ttyUSB0.

Connection Tip

After identifying the correct port, configure your terminal program with the settings above and open the connection. Upon powering up the ByteCradle, you should see output from the board if the connection is established correctly.

Boot screen

If everything is working correctly, you should see the following boot screens as shown below.

For the TINY board:

+----------------------------------------------+
| BYTECRADLE /TINY/ ROM                        |
+----------------------------------------------+
| RAM  : 0x0000 - 0x7EFF                       |
| ROM  : 0x8000 - 0xFFFF                       |
| IO   : 0x7F00 - 0x7FFF                       |
| ACIA : 0x7F04 - 0x7F0F                       |
+----------------------------------------------+
|     SELECT CATEGORY                          |
|                                              |
| (t) Test routines                            |
| (a) Applications                             |
| (g) Games                                    |
| (m) Monitor                                  |
+----------------------------------------------+

and for the MINI board:

 ____             __           ____                      __   ___
/\  _`\          /\ \__       /\  _`\                   /\ \ /\_ \
\ \ \L\ \  __  __\ \ ,_\    __\ \ \/\_\  _ __    __     \_\ \\//\ \      __
 \ \  _ <'/\ \/\ \\ \ \/  /'__`\ \ \/_/_/\`'__\/'__`\   /'_` \ \ \ \   /'__`\
  \ \ \L\ \ \ \_\ \\ \ \_/\  __/\ \ \L\ \ \ \//\ \L\.\_/\ \L\ \ \_\ \_/\  __/
   \ \____/\/`____ \\ \__\ \____\\ \____/\ \_\\ \__/.\_\ \___,_\/\____\ \____\
    \/___/  `/___/> \\/__/\/____/ \/___/  \/_/ \/__/\/_/\/__,_ /\/____/\/____/
               /\___/
               \/__/
  ____  ______     __      ___
 /'___\/\  ___\  /'__`\  /'___`\
/\ \__/\ \ \__/ /\ \/\ \/\_\ /\ \
\ \  _``\ \___``\ \ \ \ \/_/// /__
 \ \ \L\ \/\ \L\ \ \ \_\ \ // /_\ \
  \ \____/\ \____/\ \____//\______/
   \/___/  \/___/  \/___/ \/_____/

Starting system.
Clearing user space...   [OK]
Connecting to SD-card... [OK]
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