Fireside is the seven-inch touch dashboard that lives on the wall, runs the thermostat, controls the lights, and pulls double duty as a glanceable view of everything on the rig. To make a screen that big feel instant under your finger, we moved off the ESP32-S3 and onto the ESP32-P4. The new video walks through the chip, why it matters, and what it changes for the UI.
What is the ESP32-P4
The ESP32-P4 is Espressif's first dual-core RISC-V application processor, clocked up to 360 MHz with a dedicated MIPI-DSI block for driving high-resolution displays without bit-banging pixels through software. It has the kind of peripherals you actually want for an in-cabin touch panel: a 2D pixel pipeline that LVGL can lean on for blits and fills, a MIPI camera input we are not using yet but are happy is there, real USB high-speed, and enough internal SRAM plus PSRAM headroom to keep a 1024x600 framebuffer responsive.
One thing the P4 does not have is a built-in radio. That sounds like a downside until you see how Espressif solved it. Pair the P4 with an ESP32-C6 over SDIO, run the esp_wifi_remote and esp_hosted components, and the C6 becomes a transparent network coprocessor. Fireside gets WiFi 6 and Bluetooth LE from the C6 while the P4 spends its cycles on what users actually see: the LVGL render loop. The TLS-encrypted MQTT connection to Headwaters lives on the C6 side of that link. The dashboard you see on the screen never has to share a core with the radio stack.
The board we picked
The hardware is the Waveshare ESP32-P4 WiFi6 Touch LCD 7B. It packages the P4, the C6, a 7-inch 1024x600 capacitive touchscreen on MIPI-DSI, a microSD slot on its own SDMMC bus, USB-C, and the power tree all in one part order. That last point matters. The Milepost variant of the same display class lives on the Waveshare ESP32-S3 7-inch board. Same family of vendor, same mounting story, same enclosure approach, different brain. We did not have to invent a new carrier PCB to chase the chip change.
The build target moves from esp32s3 to esp32p4, the toolchain moves to ESP-IDF v5.5.2, but the rest of the picture stays familiar: LVGL v8 for the widget library, EEZ Studio for the UI source-of-truth, an SD card on first boot for WiFi and MQTT credentials, and NVS for everything after that.
What changes when you have headroom
Most of what the P4 buys you is invisible in the best possible way. Animations that were tolerable on the S3 are smooth. Touch latency that was occasionally noticeable when MQTT traffic burst is gone, because MQTT is not on the same core anymore. Color depth and font rendering choices that we had to be careful about now are not a budget conversation. The framebuffer fits, the redraws are fast, and the screen feels like a tablet rather than an embedded panel.
The platform-level shape did not change. Fireside is still an MQTT client on the rig's own broker. Headwaters still runs that broker offline. The same local/lights/+/status, local/energy/status, local/airquality/temphumid, and local/gps/… topics that Milepost subscribes to are the topics Fireside subscribes to. Two displays, two chips, one wire-level contract. That is the part that lets us pick whichever microcontroller fits the form factor without rewriting the rig around it.
Where to go next
The Fireside firmware lives in TrailCurrentFireside on GitHub, including the EEZ Studio project, the SD card provisioning format, the MIPI-DSI display config, and the ESP-Hosted SDIO wiring. The companion wall display on the ESP32-S3 is in TrailCurrentMilepost. If you are picking a microcontroller for a 7-inch panel project of your own, the video is the fastest way to decide whether the P4 is the right move, or whether the S3 still earns its slot on a smaller, simpler display.
The video went up on @trailcurrentopensource, the behind-the-scenes channel for hardware reviews, firmware deep dives, and the kind of detail that does not belong in a product video. If that mix is what you came here for, that is the channel to subscribe to.