Wiring Platform

Bob KondnerThe SunDuino uses a single 25 pin male D connector for all signals and power. Both the BB25E and BB10B have the same connector pinout. Please note the SunDuino PCBs are NOT protected against reverse battery connection, be careful not to connect a battery in reverse.

The BB25E main power outputs (+5.0, +3.3 and +/- 12) are optically isolated from the processor GND. If the I2C or RS-232 signals are to be used with circuits powered but the main outputs the processor GND (pin 5) must be connect to the main Power GND  on pin 10, 11 or 23.  A thermistor is required for battery charging. The thermistor is connected between pin 18 and pin 5. A thermistor is NOT optional, accurate charging requires knowledge of battery temperature.

J1 - Input Connector (8 Screw Terminals)

J1 Provides for connection of:

  • DC Input Power from AC Adapter or Solar Panel
  • Connection of Battery and Thermistor
  • Connection for External On/Off Switch

The Thermistor is NOT optional. Not connecting a proper thermistor will cause battery under or over charging.

A diode and fuse protects against revers connection of battery. Reverse connection of a battery will cause the diode to conduct and the fuse to open.

9 Pin Female D Connector

This connector provides RS-232 serial connection for direct connect to a PC. This 9 pin female D is wired as DCE as a PC is wired DTE. A straight through connect is used when connecting to a PC.

J2 - Output Connector (11 Screw Terminals)

J2 provides output power (Regulated Voltages) and signals:

  • +5V, +3.3V, +/-12V and Power Return
  • Always ON 3.3V from Internal Regulator
  • Internal Processor GND
  • I2C Signals SCL and SDA
  • User Analog Input

When using I2C on a BB25E the output Power Return must be tied to the internal processor GND. On the BB10B this connection exists by default.

25 Pin Female D Connector

This connector attached directly to the SunDuino 25 pin connector.