Hi there

some additional information: same Mac, same OS X Yosemite, same USB port, same USB cable and same M5AtomLite / Matrix, but using a virtual machine running Ubuntu 18.04 and flashing works just fine. I guess this suggest that there is some subtle difference in the FTDI driver of OS X and Ubuntu.

Felix

Hi there

Although I don't have a solution I wanted to share my results regarding flashing M5StickC, M5AtomLite and M5AtomMatrix . I am using VSCode/PlatformIO on two Macs with different OS:

• OS X Yosemite (10.10.5):
  M5StickC (success), M5AtomLite (fail), M5AtomMatrix (fail)

• macOS High Sierra (10.13.6):
  M5StickC (success), M5AtomLite (success), M5AtomMatrix (success)

Checking System Information / USB I can see that M5StackC reports version 4.00 and the two M5Atoms show version 5.00.

Anyways, from System Information / USB it looks like the custom USB chips in M5StickC and M5Atoms report as FTDI but I guess they aren't perfect copies and therefore different results are seen with different setups.

Felix

Hello @Johnny241

Yes, from what I am reading Ethernet seems to be a bit tricky. I assume you were able to flash and run the Arduino Modbus WiFi example, correct? If so, I'd continue with a simple Ethernet example (not Modbus related) to get familiar with Ethernet and the LAN module. Only then I'd try to modify the Arduino Modbus WiFi example and replace WiFi with Ethernet.

Felix

Hi @fblais

which demo web server did you try? I am able to run below web server code successfully on my M5Stack Grey with LAN module attached.

M5Stack/examples/Modules/LAN_W5500/WebServer/WebServer.ino

Note: I had to adjust the IP address to match my local network. Maybe that is your issue as well?

Good luck
Felix

Hi @davesee @Tristar

In my M5Stack Grey the two ICs (MPU6886 and BMM150) are on a small daughter board which was soldered to the underside of the Groove connector (GND, 5V, SDA, SCK). An additional pin provides 3.3V for the two ICs. But I am afraid the interrupt line coming out of the MPU6886 is not connected at all.

Please note: My M5Stack Grey board reads 2018.3, so maybe the daughter board was merged with the main board in later revisions?

Felix

Desoldered daughter board:

Hi FunkyFab

interesting... Thanks for sharing. Glad you got it working again.

Cheers
Felix

Hi Johnny241

there is an Arduino library called ArduinoModbus which might work for you. It includes example code for a modbus slave (and master). The examples use WiFi but hopefully replacing WiFi with Ethernet isn't too hard.

https://github.com/arduino-libraries/ArduinoModbus

Best of luck
Felix

Hi FunkyFab
normally when that happens I connect GPIO0 to GND and then connect power to force the ESP32 into download boot mode. However GPIO0 doesn't seem to be exposed on the M5Atom. Maybe GPIO0 is at least connected to an internal test point on the PCB inside the M5Atom? I am only guessing here as I don't own a M5Atom.
Good luck.
Felix

Hello Thomas

If I read your code correctly the UDP packets are sent out via WiFi instead of the Ethernet interface. I think you'll need to include Ethernet2 library (from M5 Stack W5500 WebServer example) and then include and declare the following:

#include <Ethernet2.h>
#include <EthernetUdp2.h>

EthernetUDP Udp;

instead of

WiFiUDP Udp, Udp2 ;

The Ethernet interface needs to be initialised as well with something like this (taken from M5Stack W5500 WebServer example):

#define SCK 18
#define MISO 19
#define MOSI 23
#define CS 26

// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 1, 177);

  SPI.begin(SCK, MISO, MOSI, -1);
  Ethernet.init(CS);
  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip);

Note: all of the above is untested and might need some additional fine tuning.

Good luck!

Cheers
Felix

Hello all

the reason nothing can be seen on the LCD during deep sleep is that the backlight is off. The LCD backlight is driven by GPIO32 (PWM) which is stopped when the ESP32 goes into deep sleep. Luckily GPIO32 can be controlled by the Ultra Low Processor (ULP) too. Below is a small test program which implements PWM for GPIO32 with ULP C macros / assembler.

Cheers
Felix

#include <M5Stack.h>
#include "esp32/ulp.h"
#include "driver/rtc_io.h"

const int lcdBrightness = 1; // (1-255)

void ulp_start(void) {
  // Slow memory initialization
  memset(RTC_SLOW_MEM, 0, 8192);
  // M5Stack LCD backlight is connected to GPIO32 (specify by +14)
  const gpio_num_t lcdPWMPin = GPIO_NUM_32;
  const int lcdPWMBit = RTCIO_GPIO32_CHANNEL + 14;
  // GPIO32 initialization (set to output and initial value is 0)
  rtc_gpio_init(lcdPWMPin);
  rtc_gpio_set_direction(lcdPWMPin, RTC_GPIO_MODE_OUTPUT_ONLY);
  rtc_gpio_set_level(lcdPWMPin, 0);
  // Define ULP program
  const ulp_insn_t  ulp_prog[] = {
    M_LABEL(1),
    I_WR_REG(RTC_GPIO_OUT_REG, lcdPWMBit, lcdPWMBit, 1), // on
    I_DELAY(lcdBrightness * 100),
    I_WR_REG(RTC_GPIO_OUT_REG, lcdPWMBit, lcdPWMBit, 0), // off
    I_DELAY(25500),
    M_BX(1),
  };
  // Run ULP program
  size_t size = sizeof(ulp_prog) / sizeof(ulp_insn_t);
  ulp_process_macros_and_load(0, ulp_prog, &size);
  ulp_run(0);
}

void setup() {
  M5.begin(true, false, true, false);
  M5.Power.begin();
  M5.Lcd.println("Put something onto the LCD...");
  ulp_start();
  M5.Lcd.println("Going to deep sleep");
  esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_PERIPH, ESP_PD_OPTION_ON);
  esp_deep_sleep_start();
}

void loop() {
}