The starter project¶
JP150PCB 1.3PCB 1.4Jan PřibyslavskýThis page does not apply to the product or PCB revision chosen in the header.
JP150_DSP_basic_passthrough_ASRC_<version>.dspproj is the SigmaStudio 4.7 project the module ships
with: a passthrough of the selected input to both power stages, with the pieces the firmware relies
on. Every own design starts from it. The project of the current release is on
Downloads; the DSP image of the update bundle for PCB 1.4 is this
project's export.
What is in it¶
The main schematic holds four hierarchy boards and a marked area for your own processing:
| Board | What it does | Keep |
|---|---|---|
| INPUTS_PROCESSING | Receives the six sources (I2S, USB, Bluetooth, Wi-Fi, S/PDIF, the test tone), brings the asynchronous ones to the DSP's sample rate with sample-rate converters, and selects one of them with the input mux the firmware drives. It also holds the level meter the firmware reads | Yes: the firmware's input selection and its level meter depend on the cells and table entries inside (IPAT and parameters) |
| AMP0_OUT, AMP1_OUT | Route the stereo signal to the two TAS3251 power stages: left on OUT A, right on OUT B of each stage | Yes, unless you redesign the output routing on purpose |
| I2S_OUT | Drives the I2S output connector | Yes |
| Your processing | The area between the input selection and the outputs, marked in the schematic | Yours |
Everything hardware-specific, the serial ports, the clocking, the sample-rate converters, is inside the boards: do not edit them, or the design may stop working with the firmware. Add your equalisation, crossovers, limiters and routing in the marked area, between the input selection and the output boards.
With the default program the DSP LED flashes at 1 Hz (on PCB 1.4 it is driven by the DSP's MP7 pin), which is how you see that a program runs after a download or a boot-memory write.
One design, two boards¶
The design is the same on PCB 1.3 and 1.4; the self-boot memory differs. The project stores the memory settings of one board at a time, so an export made with the settings of the other board does not boot (Writing the boot memory). The project of a release carries the PCB 1.4 settings; set the PCB 1.3 values before a write to a PCB 1.3 module and check them before every write, because SigmaStudio 4.7 does not always keep changed memory settings.
Working with it¶
- Open the project, check the USBi in the Hardware Configuration tab, and Link Compile Download to try a change on the running DSP (Quick start).
- When the design is right, write it into the boot memory: on PCB 1.4 from MuraLink with the
project's
E2Prom.Hexexport (Boot memory with MuraLink) or through the DSP from SigmaStudio; on PCB 1.3 through the DSP from SigmaStudio. - Keep the exported files with your project: the module has no record of which program its boot memory holds (known issue KI-09).