Getting Arachnid on the Web

[ClippyTheDiode]

This week on stupid pedal tricks, we put an Arachnid on the Web!

The project is written in CircuitPython running on a Raspberry Pi Pico W.
It gives you a web form to upload new EEPROM images.
It is very simple in it's current form, but could be used to program single or all 8 programs.
It is also possible to read back the current programs and save them to your PC.

Here is a sample video of it.

 

[ClippyTheDiode]

Here is the current code. It will read and write .bin files. It started life as one of the example scripts from the adafruit_httpserver library. I just tweaked some stuff and added the EEPROM code.

With this code you can write starting at the first sector, up to the whole chip.
It currently only works with binary files, not Intel Hex.
So your file size should be 512 bytes or a multiple of 512, up to 8x512 = 4096 bytes.

The current adafruit_24lc32 library is pretty slow. It takes about 4 seconds to write a program, and about 30 seconds to write all 8 programs. Reading is faster.

Once you have flashed a new program(s) to the EEPROM, you must signal to the FV-1 that it needs to re-read the updated program from the EEPROM. So you must flick the program select switch to signal this to the FV-1. It is possible to have the pico strobe FV-1 pin 13 and trigger a reload, but not currently implemented.

Software Install:
Download and Install CircuitPython
Download CircuitPython Bundle
Download arachnid_web_programmer.py

Install CircuitPython on Pico
Find all the Libraries needed in the Bundle and copy them to Pico
Rename "arachnid_web_programmer.py.txt" to "code.py" and copy to Pico
Create a settings.toml file on Pico containing your WiFi Credentials SSID and Password
Open a terminal window to Pico so you can see the IP address (mdns support hopefully coming soon)
Type that IP address into a web browser


Hardware Install:
Currently the 3.3V regulator in my arachnid is only rated for 100mA, and the Pico draws about 200mA when first connecting to WiFi. Once connected it draw much lower current. Because of this you will need to either upgrade the regulator or install a second one. I would recommend installing a second one and a switch to turn it and the Pico on/off.

In my demo video I was using a micro USB cable to power up the Pico. Once it connected to my router I could unplug the USB and it could run/read/write all while powered up from the internal 3.3V regulator on arachnid. Just needed the extra oompf to connect initially.

Pico Wiring:
VSYS = 3.3V
GND = Ground
GP0 = SDA
GP1 = SCL

 

[Paradox916]

that’s pretty cool to have another programming resource out there for fv-1, I don’t know python but It’s nice to seen the digital end of diy opening up.

 

[ClippyTheDiode]

This project is a bit silly as it stands now. But it is just a stepping stone to what I would ultimately like it to be which is an "EEPROM librarian". You would be able to upload a bunch of patches to the Pico via a web browser or USB. Then from the web interface OR a local display/buttons on the pedal, be able to re-program the eeprom as needed.

It could also be a good starting point for "pre-sets". If we replaced the 3 FV-1 pots with software pots, and added some rotary encoders to the Pico we could have "pre-set" support. (I probably won't take the project that far. Going to need someone way better at web applications for that one)