Igniter Controls and DAQ Rev 2 (2024)
See https://chasemacdonnell.net/igniter-controls-and-daq-2022/ for more information on the original igniter system.
GitHub: On a private Gitea instance, will work on transferring to my GitHub.
Using all of the issues I discovered from my original igniter system, I designed a new custom controller to allow for better diagnostics and more reliable testing. This project was divided into two phases: hardware design/assembly and software design/implementation. Initially, I designed a custom solenoid controller to achieve the following goals:
- Provide per-solenoid diagnostics (over-current, short, open-load, over-temperature)
- Provide more reliable spark-plug controls.
- Provide accurate solenoid timings.
To achieve the strict timings we wanted for this system, I swapped from using standard ethernet to a custom automation protocol called EtherCAT. On the board, there is a LAN9252 EtherCAT Controller which implements the PHYs and hardware necessary for EtherCAT. That controller then connects to the main RP2040 microcontroller over SPI, with the RP2040 reading the state of then writing/reading data to the LAN9252.
Then, each solenoid was driven by a high-side switch from Infineon, which had it's current limit set to 0.8A via a configuration resistor. That high-side switch provides a single wire output for each solenoid indicating a fault on that solenoid. That fault could be over-current, a short, over-temperature, or a open-load.
Finally, a port was provided that output a PWM signal that could be use to drive a racing ignition coil for the sparkplug.
An additional plus to swapping to EtherCAT is we replaced our previous IO-Link Master with a AL1332 IO-Link Master w/ EtherCAT Controller. This allowed us to integrate our entire control and data acquisition system into one daisy-chained ethernet cable and two power cables, making setup and repairs extremely simple.
