To create a module for the signpost, it must conform to the module specification.
All in inches.
| Description | Signal | Pin | Pin | Signal | Description | |
|---|---|---|---|---|---|---|
| GND | 1 | 2 | 5V | |||
| Reserved | 3 | 4 | VCCIO | I/O voltage the module uses. This must be fed by the module to set the I/O voltage. | ||
| I²C clock line. | SCL | 5 | 6 | SDA | I²C data line. | |
| Pulse per second from GPS. | PPS | 7 | 8 | MOD_OUT | Interrupt line to the controller. Allows modules to signal the controller. | |
| Reserved | 9 | 10 | MOD_IN | GPIO from controller to module. | ||
| USB Data+ signal. | USB_D+ | 11 | 12 | USB_D- | USB Data- signal. | |
| USB bus voltage (5 V). | USB_VBUS | 13 | 14 | GND | USB GND. |
Modules may choose to implement a Debug header as well. The Debug header will allow for easier interactions with modules while they are connected to the development version of the backplane.
| Description | Signal | Pin | Pin | Signal | Description | |
|---|---|---|---|---|---|---|
| GND | 1 | 2 | GPIO1 | Output line to control LED on development backplane | ||
| UART data from the module | TX | 3 | 4 | RX | UART data to the module | |
| Output line to control LED on development backplane | GPIO2 | 5 | 6 | !Reset | Active-low reset for the module microcontroller | |
| JTAG line for the module microcontroller | SWDCLK | 7 | 8 | SWDIO | JTAG line for the module microcontroller |
We have built sensor modules using both KiCAD and EAGLE. Generic module libraries that include a reference outline and header location are available in the Signpost Eagle Library.
All example sensor modules can be found in the modules folder.
We generally recommend using a processor supported by Tock or ARM Mbed.
Holes in the sensor modules that allow it to screw to the signpost backplane should be plated and tied to ground.
We are happy to provide guidance on module creation! Feel free to reach out to us either through an issue or email at signpost-admin@eecs.berkeley.edu
