Hello again! :)
While I eagerly await on (what I hope to be) the final revision of my Ohm board, thought I'd drop one more update here..
1.) OV7670 module testing went well :)
2.) Fixed a few more minor errors with the PCB, as well as tweaked the following specs:
- Stepped up the user GPIO breakout to 62 pins total..
- Added a user push button (really needed one for things like system reset etc.. so I bit the bullet :-).
- Added some additional circuit protection bits that were missing on the original Ohm zero..
- To get the maximum possible use out of my board (ie: implementing multiple video inputs), I may need to offer the 45k variant ECP5 for the FPGA.. For many things however, the 24.5k variant seems to be acceptable. It can (for example) accept the minimig core, albeit at ~80% slices and 100% PLL blocks usage..
3.) Started work on my very first (and relatively simple) 'hat' for the Ohm board - a 'retro ports breakout' hat containing:
- 2 x C64 style game ports (for joystick and game paddle support).
- 1 x PS/2 combo port (for keyboard and mouse support via a Y-splitter cable).
- 1 x Audio output jack.
- ESP8266 (was ESP32, see update below) module provision (several possibilities here, needs more work ;)
Looking forward to seeing the final boards when they arrive (hopefully) by next week's end (I hope I've covered everything..) More to follow!
**** EDIT 09/06/2017: For reasons mainly relating to time, I have decided to use the ESP-12E module (ie. ESP8266) for Revision 'A' the retro breakout hat (and possibly move to ESP32 for later versions when I am in a better position to support it). I have the following interfaces wired up from the ESP to the FPGA:
- SDIO and UART interface pins wired up.
- Control signals required for ESP module control and/or firmware update (ie. RST, EN, GPIO0, GPIO15, etc.) are upported.
Both expansion hats and pre-production Ohm boards are almost ready to be shipped back to me. Next week will be an eventful one.. ;-) ****