As this OpenHardware project moves forward, we are now approaching a complete prototyping of our functionnal blocks and telecommunications interfaces control from the Linux kernel. The main functionnal blocks to be tested and validated are in our architecture based on the following buses:
- SPI (Serial Peripheral Interface) bus between the CPU and the FXO/FXS chip
- LEB (Local Expansion Bus) between the CPU and the ISDN chip
- TDM (Time Division Multiplexing) connecting the CPU, ISDN and FXO/FXS chip together to transmit the digial streams of voice channels
- GPIO (General Purpose Input Output) for the RST (Reset) signals and IRQ (Interrupts) signals
- CLK (Clock) signals architecture to be sent to the different chips
Below is a picture of our prototype boards connected together to demonstrate the functionnalities of each blocks for our software development on the Linux kernel modules:
We have been using the large prototyping breaboard from Wisher (at farnell.com on: http://fr.farnell.com/jsp/search/productdetail.jsp?SKU=1472854) that is great to split different wires connectivity on the breadboard.
In the next posts, we will describe the results and work done on each buses to achieve the first global tests for voice channel routing with our XiVO IPBX OpenHardware.