Hannah Development Board
Hannah is a development board for the hobbyist with many useful peripherals on board.
Note The Hannah is not a great ‘first board’ to learn on as most of the functionality is hidden behind various I²C devices, including the buttons and RGB LED.
Power
Power can be supplied using a USB Mini-B cable from a USB Charger or standard USB Port, though the data lines are not connected to anything. Optionally, four AA batteries may be fitted to the carrier on the rear side of the board. You may select between USB power and battery power by placing a shunt on the power select header. Please note that Hannah does not have any circuitry for charging a battery and you should never short USB power to the battery pack.
Peripherals
Hannah has on board:
- Rotary Potentiometer
- 2x Push Buttons
- RGB LED
- RGB Light Sensor
- Temperature Sensor
- 3-axis Accelerometer
- Hall Sensor
- 2x Servo Output
External Signals
Hannah bring out the following signals to pads:
- 5x GPIO
- I²C Bus (3.3v signal levels)
- Clock
- 3.3V and Ground
0.1-inch pitch SIL headers may be fitted if required.
Architecture
Clearly Hannah boasts many more peripherals than could be directly connected to the six general purpose pins of an imp. This is achieved through use of an I²C bus and an IO expander. The imp's pins are assigned as follows:
| Pin | Mode | Description |
|---|---|---|
| Pin 1 | Digital input | Interrupt from GPIO expander |
| Pin 2 | Analog input | Potentiometer wiper |
| Pin 5 | Digital output | Servo port 1 PWM signal |
| Pin 7 | Digital output | Servo port 2 PWM signal |
| Pin 8 | I2C SCL | I2C Bus |
| Pin 9 | I2C SDA | I2C Bus |
The IO expander pins are assigned as follows:
| Pin | Mode | Description |
|---|---|---|
| IO0 | Input | Button 1 |
| IO1 | Input | Button 2 |
| IO2 | Input | Hall Switch |
| IO3 | Input | Accelerometer interrupt |
| IO4 | Input | Temperature sensor alert interrupt |
| IO5 | Output | RGB LED Green |
| IO6 | Output | RGB LED Blue |
| IO7 | Output | RGB LED Red |
| IO8 | Output | Potentiometer enable |
| IO9 | Output | RGB light sensor sleep |
| IO10 | Output | Server ports 1 and 2 power enable |
| IO11 | GPIO | Spare |
| IO12 | GPIO | Spare |
| IO13 | GPIO | Spare |
| IO14 | GPIO | Spare |
| IO15 | GPIO | Spare |
The I²C bus has the following on-board peripherals:
| 8-bit Address | 7-bit Address (do not use) | Part No | Description |
|---|---|---|---|
| 0x38 | 0x1c | LIS331DL | 3-axis accelerometer |
| 0xE8 | 0x74 | ADJD-S311-CR999 | RGB Light Sensor |
| 0x98 | 0x4C | SA56004ED | Temperature sensor |
| 0x7C | 0x3E | SX1509BULTRT | IO Expander |