Raspberry Juice
Jump to navigation
Jump to search
Overview
The Raspberry Juice serves as a power switch for the Raspberry Pi. This expansion board can turn the power on or off at a scheduled time. shop link
Specifications
The Juice always uses about 2mA/10mW. The board is rated for a maximum current of 1A.
Use
The Raspberry Juice can be found using I2C or SPI at address 0xA4, and has the following read ports: All times are in ms, and are 32 bits in size.
| Port | Returned value (in milliseconds) | |
|---|---|---|
| 0x20 | Time until power off | |
| 0x21 | Time until power on | |
| 0x30 | button active | 0: don't react to button press. 1: react to button press (default), others: undefined. |
| 0x31 | external input active | 0: inactive (default), 1: active, others: undefined. |
| 0x32 | external input polarity | 0: active low (default), 1: active high, others: undefined. |
| 0x33 | power set on/off state | 0: off, 1: on, others: undefined. |
| 0x38 | button active powerupstate | 0: don't react to button press. 1: react to button press (default), others: undefined. |
| 0x39 | external input active powerupstate | 0: inactive (default), 1: active, others: undefined. |
| 0x3a | external input polarity powerupstate | 0: active low (default), 1: active high, others: undefined. |
| 0x3b | power set on/off state powerupstate | 0: off, 1: on, others: undefined. |
Additionally, the following can be written to the Juice:
| Port | Effect | |
|---|---|---|
| 0x20 | Set the time in milliseconds until power off | |
| 0x21 | Set the time in milliseconds until power on | |
| 0x30 | button active | 0: don't react to button press. 1: react to button press (default), others: undefined. |
| 0x31 | external input active | 0: inactive (default), 1: active, others: undefined. |
| 0x32 | external input polarity | 0: active low (default), 1: active high, others: undefined. |
| 0x33 | power set on/off state | 0: off, 1: on, others: undefined. |
| 0x38 | button active powerupstate | 0: don't react to button press. 1: react to button press (default), others: undefined. |
| 0x39 | external input active powerupstate | 0: inactive (default), 1: active, others: undefined. |
| 0x3a | external input polarity powerupstate | 0: active low (default), 1: active high, others: undefined. |
| 0x3b | power set on/off state powerupstate | 0: off, 1: on, others: undefined. |
examples
So, for instance, writing 10000 to port 0x21 and 1000 to 0x20 will cut the power in 1 second, and then turn on the power 9 seconds later.
bw_tool -I -D /dev/i2c-1 -a a4 -W 21:2710:i 20:3e8:i
Note that bw_tool works with hexadecimal numbers. So 2710(hex) is 10000 decimal, and 3e8 is 1000 decimal.