Search results

  1. E

    Vector Font library for Teensy 3.6

    Hi Michael This is an old post, I realise, but I just found it and decided to have a go at adapting your code for the Teensy 4.1 and my vstcm vector generator PCB which targets real vector monitors (https://github.com/english1234/vstcm). It works quite well! Here's a quick video (sorry for the...
  2. E

    Teensy 4.1 simultaneous SPI.transfer calls with eventhandler using LPSPI 1, 2 & 4

    Thanks for your reply. I have managed to do concurrent writes to the 2 easily accessible SPI busses now after repinning my PCB, but there is no performance gain, possible as i'm only writing 16 bits to each at a time. Oddly, if I use the hardware CS pins 10 and 0 the transfer command doesn't...
  3. E

    Sending data to external DAC using Teensy 4.1, SPI and DMA

    I have now got SPI.transfer16 and the non blocking SPI.transfer with event handler working, but I'm addressing each of the 3 MCP4922 DACs with dual channels sequentially and sending 12 bits of data + 4 bits of control to each. Neither type of transfer is giving sufficient performance for my...
  4. E

    Teensy 4.1 simultaneous SPI.transfer calls with eventhandler using LPSPI 1, 2 & 4

    I am using a Teensy 4.1 to write to 3 dual channel MCP4922 DACs with the non blocking SPI.transfer command and an event handler (eg SPI.transfer(dmabuf, nullptr, 2, callbackHandler); ). I'm currently writing to each DAC sequentially by setting the CS pin to low, doing the transfer and moving on...
  5. E

    Sending data to external DAC using Teensy 4.1, SPI and DMA

    I tried out transfer16 and just could not get it to work for some reason. I didn't realise that there was transfer32. I'll try again... thanks for the suggestion.
  6. E

    Sending data to external DAC using Teensy 4.1, SPI and DMA

    Yes, performance is lacking as I'm updating the 5 channels sequentially. I'm using the simple form of SPI.transfer with one parameter which is the data (which is blocking, I believe). There seems to be another way of using SPI.transfer with an eventhandler callback procedure, which is...
  7. E

    Sending data to external DAC using Teensy 4.1, SPI and DMA

    Anyone able to offer any advice on this? It's an open source project for the arcade community. I was thinking that FlexIO could be an alternative solution to DMA maybe?
  8. E

    Sending data to external DAC using Teensy 4.1, SPI and DMA

    I have just posted up the complete project on Github: schematic, gerber, BOM, code, etc in the hope that this will encourage someone to spend a little time getting DMA up and working on this exciting (if you are a vector graphics / arcade game nerd) project! It's all here...
  9. E

    Sending data to external DAC using Teensy 4.1, SPI and DMA

    I'm using Arduino 1.8.19 / Teensyduino 1.56 to code a custom PCB which has a Teensy 4.1 and 3 external MCP4922 dual channel DACs. The code is meant to take a buffer of data and send it to the appropriate DAC/channel. There is no receive part back to the Teensy. I had previously adapted code...
Back
Top