Hi Alan,I am really happy to got your interest. Replacing the Pi with an EsPiFF with Nuttx is also our intention.
The SWD for the RP2040 is alredy broken out, on J5, pin 6(SWCLK) and pin 8 (SWDIO). The connector J5 is a DF11, 2mm spacing connector, we will add cables with 2.54 Duponts on the other side. The RP2040 have exclusive pins for SWD, so no limit on functionality. Just for the ESP32, we need to add the JTAG header. We used that DF11 connector, to make these pins accesable from outside, when the EsPiFf is in a Raspberry Pi 4 enclosure, what have 2 mini HDMI connectors at this position. Other connectors would be too big for the openings for mini HDMI.
In the past, I did also STM32 boards, until the chip crisis made most of the STM32Fxxx unavailable. This is the big advantage of the ESP32, they are always available. I have not yet jumped on the GD32xxx and friends as pincompatible? replacement, that could be an way out. But 8 MB RAM on a board, means for most MCUs external RAM, whats included with the ESP32-WROVER. I am hoping, that (one day) to load ELF binaries from SDcard into memory and execute it, as Linux is doing. This will open a new chapter in using microcontrollers, and Nuttx is already nearly there.
Would be happy to see the EsPiFF one day in your Nuttx Videos! best regards, Michael Am 2022-10-26 14:56, schrieb Alan C. Assis:
Hi Michael, Congratulations! You created a really great board!!! I'm sure that many people here will be interested on it, those who are really interested to contribute. The idea of using RPI form-factor is really good. Actually we were discussing about the idea of creating some RPI-like board to replace high level Linux system with a system running NuttX RTOS. I think adding JTAG for ESP32 and SWD for RP2040 will be very useful, please include it for the final board. A friend of mine created a nice and simple board for NuttX that he released as open-source: https://github.com/lucaszampar/NuttX_STM32F4_RS485_DevBoard He send me some pictures that I put on my flickr: https://live.staticflickr.com/65535/52456145643_97eca8e9b1_o.jpg https://live.staticflickr.com/65535/52455885674_94eba29fcc_b.jpg Soon, he will submit support to mainline. BR, Alan On 10/26/22, michael.sch...@mdc-service.de <michael.sch...@mdc-service.de> wrote:Dear Nuttx developers, we have developed the EsPiff (ESP32+RP2040 on the Raspberry Pi FormFactor), a open source board to replace RasPi's and there clones, where the high processing power and/or Linux is not needed, but stability andthe reuse of RasPi HATs are required. The github home is https://github.com/MDCservice/EsPiFF We will also offer the EsPiFF on CrowdSupply https://www.crowdsupply.com/mdc-service-wittenburg-gmbh/espiff We would like to send a few boards for free to Nuttx developers, to improve Nuttx compatibility. Would there be interest? A high level summary about the EsPiFF: An ESP32-WROVER-I module with 16 MB Flash, 8 MB PSRAM is taking care - wired Ethernet via a IP101 PHY, - Wifi (need an external Wifi Antenna with uFL connector), - 3 serial UARTs, - one the 3 serial UARTs is used for programming via a CH340 USB-UART chip, what can be enabled/disabled with jumpers, - I2C port expander PCA 9557 for some chip select signals and 3 user LEDs, - SDcard in SPI mode, - external real time clock, with supervisior, - 2kB FRAM,- USB Type-C connector for up to 5V/3A, connected to the CH340 USB-UARTto program the ESP32 An RP2040 (Pi Pico) what takes care the 40 pin RasPi header, - connected to the ESP32 via SPI, - UAB-A connector, also used to program the RP2040 (need to hold the boot button while power the board). In earlier versions, we had the LAN8720 PHY, but as others (Olimex, wESP) we also got problems and replaced it with the IP101 since v3.1. Currently, there is no HW debugging broken out on the board. But we could add a JTAG header on the bottom side, with TDO, TDI, TCK, TMS, GND, 3V3 in the next board production run. The ESP32 has the JTAG pins on GPIO12, 13, 14, 15, what are used for SPI on the EsPiFF, so codeusing the SPI could not be debugged while JTAG is using the pins. Wouldit still make sense to build in the JTAG header? Would be glad to get your feedback, Michael
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