Positron BASIC Community

HI Charlie

I received the 18F27Q43 Dev board today and have designed and released a Galvanically Isolated 4CH multiplexed 12CH ADC piggyback board for you based on the MAX22530AWE.  This shouldn't cause any issues with back-powering, since the VDD, Signal, and GND pins are isolated.  I have the parts for this but need to build it once the PCB arrives; the Dev just needs the PIC, as these were out of stock at LCSC/JLC.

The EMU worked well with Les' game, so that's completed. I just need to develop the FPGA Dev with a Retransmit, isolated HDMI, and a separate JTAG programmer based on the FTDI.  I have ordered a couple of FPGA chips, and we will see if these are genuine!

Be a few more weeks before I have a full dev setup with working Positron Code. I will also complete a MAX22530 library and a demo SSD1306 with Les lib driving the HDMI. 



Keep you posted

That's really good Jon. I think the museum will be much indebted to you. No rush. Thank you.

Charlie

Hi Charlie

Update on this.

I completed a new dev board for the Gowin FPGA; see below. This has an RP2354A handling the FPGA management functions and will help with debugging future Verilog.  Should be a really nice FPGA dev platform with a direct connection to the RP2354A for any post-processing and programming, including more memory and a Silabs clock gen IC phase-synchronised to the FPGA clock.  Some headers for RF or slower 8-bit parallel DACs and ADC.  An SPI header to use the board as an HDMI SSD1306EMU.  Added a 3V3 Jtag (missing off the tang nano) to directly flash the FPGA and some surge and ESD protection on the HDMI.  Will take a couple of weeks to come in.

I have also ported the RP2354A to a separate dev board and added 12 x WS LEDs and a Wi-Fi module; this could be used with MicroPython or C to run some very large display functions and Wi-Fi stuff. 

I will also bring up the isolated ADC board and the PIC DEV with Les OLED lib that I have been testing and write some code for the demo on the 27Q Dev for you

Wow! Who's been a busy boy! That's brilliant Jon, although quite a few of those acronyms left me miles behind. When you are ready we should get together, probably at the museum, and get something wonderful underway.

Charlie

Still working on this, Charlie.  I have the FPGA up and running and am building demos spanning decades of computing history; this is in addition to the SSD1306 EMU.  They can be activated via secret SSD1306 commands to change the demo, cycle through demos, or display a blank SSD screen.  You can still control the HDMI from the PIC when selected.

This gives you some idea of what is possible even on an SSD1306!  The emulator streams SSD1306 SPI data directly to the decoder within the FPGA and blocks all external commands except the secret commands.  You can then have full control of the emulator from a PIC, or allow the user to interact to select a screen. 

Some tuning needs to be done to get the LVDS levels right for a monitor, but I need a high-speed differential probe that's in my lab.