Alloy a fusion of opensource FPGA and WIFI Microcontroller

[Folknology]

Alloy

Alloy an OpenSource hardware fusion of FPGA and WiFi Microcontroller in a Feather compatible layout

Alloy Repository

[Folknology]

First Alloy prototype running

[Folknology]

Latest stream where I bring Alloy up and go through the firmware to program the Ice40

[lawrie]

Just watching your videos on twitch. I notice that in your bitstream loading code you have sleep(0.2). The python sleep parameter is in seconds, so your waits are in milliseconds not microseconds.

You also say there is no += in python, but there is. It is ++ that is doesn't have.

Also your write_bytes function doesn't look as if it writes out the last chunk of data if it is less than 64 bytes.

[Folknology]

Just watching your videos on twitch. I notice that in your bitstream loading code you have sleep(0.2). The python sleep parameter is in seconds, so your waits are in milliseconds not microseconds.

Thanks for that.

You also say there is no += in python, but there is. It is ++ that is doesn't have.

Yeah sorry I meant no increment in python, quite right.

Also your write_bytes function doesn't look as if it writes out the last chunk of data if it is less than 64 bytes.

I believe the bit image is a multiple of 64 so it works fine but I do still need to optimise, I was thinking maybe 16 as I think that is the size of the SPI DMA buffer, need to check this.

Thanks for the feedback @lawrie much appreciated

[lawrie]

I believe the bit image is a multiple of 64 so it works fine but I do still need to optimise, I was thinking maybe 16 as I think that is the size of the SPI DMA buffer, need to check this.

The comparision with num_bytes = 104161 does not make it look like the length is a multiple of 64 bytes. Also print("Wrote {} bytes".format(byte_count)) will be wrong as it includes 64 bytes that were not written.

I like the way your series of videos shows the whole process of designing an open source FPGA board including the hardware, software and gateware. I have found them very interesting, but the length of the videos can be an issue.

[Folknology]

Latest stream is up covering Alloy and it's tile carrier, we also develop nMigen board support for Alloy.

[lawrie]

After last night's discussion on Alloy, I wonder whether a problem with Alloy is that too many pins are connected to the ESP32 rather than the FPGA. Since all the feather pins are connected to the ESP32, any hardware connected via a breadboard will be connected to the ESP32, and the same for any hardware connected via feather wings.

With these products that are a fusion between a microcontroller and an fpga, I think the use cases where you want hardware connected to the fpga are much more common than where you want it connected to the microcontroller.

From my experience with the Ulx3s, the exception is the sd card reader, as the SD card is more often accessed from the ESP32. But on the Ulx3s the sd card pins are connected to both the fpga and ESP32 so you can access it from either.

[Folknology]

I agree about the pin usage not being FPGA centred enough, I had a rather different idea this morning after reviewing things which may change things significantly, I need to play around with the idea and let things settle a bit before I go over it..