After some troublesome debugging I finally got the SPI up and running. I can now move one of the bitmap displayed from RAM (I don’t have a RAM yet, I connected some address wire to one of the D inputs to test. This gives a nice, striped image) in X and Y. 🙂 Also, the FPGA seemed to “crash” in some way before giving me a black image after some random time. That seems to have vanished with the last bug too.
Can’t wait to get my hands on the PCB…. Hopefully it’s made in China as I type this. 🙂
Why would anyone want to have one of these, except me? Well, I don’t know. 🙂
The project plan is to have a FPGA connected to the SPI port of the Pi. The FPGA, connected to some fast RAM, will be able to output analogue signals (RGB, 24bit) and sync to a 15kHz monitor. The original plan was to have the FPGA handle a four layer bitmap (layers can display 255 colors) and 64 32×32 pixel sprites. I had to decrease the sprites to 29, since there are only 30 RAM blocks in the FPGA I’m using.
At the moment I’m waiting for my PCB. Until then I can only test using 3-bit RGB and without RAM. Sprite blocks are yet untested, but it seems to build ok.
This is a test image using the line and pixel signals from my image generator.
Right! Setting WordPress up didn’t take much time, maybe I can test the sprites a little bit somehow without the RAM…
Update: First sign of sprite life! A white square, 32×32 pixels at position 0,0. No more time tonight. Next step is to connect the SPI to Pi and see if I can move the sprite.
Having my own blog seems fun. I can document my projects a bit which will be useful since I got a real bad memory. I installed WP on my machine for testing, let’s see if it works ok. If it does, I will use it. =)