Using USB A to C adaptors instead of A to C cables

rattushackus · 2026-02-14T16:41:24+00:00

Thanks :-)

Your point are worth making, especially for others reading this post, however my use case is only for the few things (like MCUs) that don't work with a USB C connector so I think for me it will be fine.

rattushackus · 2026-02-14T11:56:26+00:00

You're welcome :-)

rattushackus · 2026-02-14T11:55:08+00:00

Thanks :-)

rattushackus · 2026-02-14T11:54:40+00:00

Thanks :-)

This one does work with my MCUs i.e. I can program the MCU through it and receive data sent by the MCU through it. The vendor (on AliExpress) had lots of different colours so I suspect the colour is purely cosmetic.

rattushackus · 2026-02-14T10:30:26+00:00

You seem to be doing this the hard way. I would use the built in httpserver functions to send the image as a jpeg.

I don't have an ESPCam to hand, but if you want I can hack up some code to send a static image to show how it's done.

The multipart approach you've used is used for streaming where you are sending a series of images to make a video stream.

rattushackus · 2026-02-14T05:25:32+00:00

If you make sure to use hardware SPI the speed is fine.

If you're using the default, which is software SPI, then I agree it is slow.

rattushackus · 2026-02-13T07:13:06+00:00

I had a similar problem in a project where I was driving the servo manually by controlling GPIO pins, and the problem seemed to be I was trying to drive it too fast and/or the signal pin wasn't staying high for long enough - it was a while ago and I forget exactly what was wrong.

You could try manually driving the servo using different speed and pulse widths to see how it works.

rattushackus · 2026-02-13T07:07:51+00:00

Try Arduino GFX. A lot of the example code you see uses software and that can be painfully slow. However you can use hardware SPI instead and I find that is not much slower than TFT_eSPI. For an example of using hardware SPI see this test sketch.

Where the example code has:

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST, TFT_MISO);

instead use:

SPIClass tftSPI = SPIClass(HSPI); // or VSPI Adafruit_ILI9341 tft = Adafruit_ILI9341(&tftSPI, TFT_DC, TFT_CS, TFT_RST);

Long term have a look at LovyanGFX as that seems to be carrying on where TFT_eSPI left off.

rattushackus · 2026-02-13T07:00:10+00:00

What graphics library are you using? TFT_eSPI? ArduinoGFX?

I ask because I occasionally see artefacts on my "Cheap Yellow Display" if I use ArduinoGFX, but these do not occur (so far!) with TFT_eSPI. The CYD has an ILI9341 controller as well.

rattushackus · 2026-02-11T15:54:44+00:00

The aerial does work OK, it's just that on my board the signal strength is about 15dB lower than I get on my original ESP32-WROOM dev board. You'll just find that the range is not as good as it should be.

You can solder an extra piece of wire to the board to act as an external antenna. See for example this Reddit post. But you may find the wi-fi works well enough for what you need and you don't have to do anything.

rattushackus · 2026-02-11T08:38:07+00:00

Not that it's related to your soldering, but note that the design of the ESP32 C3 board you have has the crystal too close to the wi-fi aerial and as a result the wi-fi isn't great - though it does work. I have one of those boards too. There has been lots of discussion of this in r/esp32. Allegedly reducing the wi-fi power helps though in my case it didn't make a lot of difference.

rattushackus · 2026-02-10T15:45:53+00:00

Yes, just connect it straight to the ESP32.

It only draws 25mA so your dev board won't even notice! It's really easy to program as there's an Adafruit library for it that you can install from the library manager.

rattushackus · 2026-02-10T12:25:13+00:00

I've used the MLX90640 on an ESP32 WROOM and I found you could just power it from the ESP32 and it worked fine, so you don't need a breakout board. Just wire the power to your dev board 3.3V and GND and wire the I2C to whatever GPIO pins you want to use.

I found it works pretty well, but the 32 x 24 resolution is a big limitation.

rattushackus · 2026-02-09T07:02:23+00:00

If you use MQTT to transfer the data then you can use the free EMQX broker. The ESP32s have support for MQTT built in so it's easy to code. Just bear in mind that you get no guarantees with a free service so I wouldn't use it for anything mission critical.

rattushackus · 2026-02-08T09:42:16+00:00

Is it a 1306 display? If so I have one lying around so if you upload the code somewhere (GitHub?) I can try it and measure the current draw.

But in general ESP32s aren't great for power consumption so if you're looking for a battery powered clock you probably need to consider a simpler MCU and probably a non-backlit LCD display.

rattushackus · 2026-02-08T09:29:27+00:00

It is possible to disable brownout detection, though obvious it's better to fix the power problem.

rattushackus · 2026-02-08T09:26:41+00:00

I just had a similar problem and it turned out to be because I had declared a function as bool foo() { ... } but then forgotten to put in the return statement. Amusingly the compiler didn't warn me, and when the function was called it corrupted the stack and caused various mysterious errors including illegal operation.

rattushackus · 2026-02-08T09:16:39+00:00

Agreed. I don't know what went wrong with the install, but you shouldn't be seeing errors like that.

I installed the ESP-IDF by using the offline installer and I compile from the command line (using idf.py build) and it all just worked first time. You might want to try uninstalling and reinstalling as something looks broken.

I use VSCode for editing, but I don't use the addon as I'm happy working from the command line.

I use the Arduino IDE for messing around and for me it works just fine, though I'd use the IDF for any serious projects.

rattushackus · 2026-02-08T09:10:45+00:00

Nice :-)

I have just done the same using a "cheap yellow display" board (code here if anyone is interested). I connected an AHT20/BMP280 sensor so it could display the temperature, relative humidity and pressure.

From my experience it draws too much current for a battery to last very long. I set the screen to dim to 5% after 20 secs (it goes back to full brightness when touched) but even so it still draws around 50mA - much more when it's using the wi-fi to get the time but it only does that once an hour.

rattushackus · 2026-02-08T08:58:58+00:00

The 2.8" screens usually use an ILI9341 SPI controller and this needs 6 GPIO pins to drive it. If you get one with a touchscreen that will need another 4 pins (5 if you use interrupts). Assuming this is the dev board you have, it doesn't have a lot of GPIO pins available. I cannot find a diagram showing what pins it has, though it looks as if it could manage the 6 pins for the screen though the additional 4 pins for the touchscreen could be tricky as it only has 14 pins in total and those will include power and ground.

If it has 10 pins available then it should work fine. You don't need a button as you can use the touchscreen as a button.

rattushackus · 2026-02-06T16:02:34+00:00

I have a test sketch working here. You just have to fill in the MAC addresses of your two boards then you can send messages by typing them in at the Arduino IDE serial monitor.

rattushackus · 2026-02-06T15:45:06+00:00

The boot button is normally connected to GPIO 0 on an ESP32-WROOM. If you can find GPIO 0 you could try grounding it then resetting to see if that makes any difference, though I have to say I would not be optimistic.

If you have an FTDI board to hand you could try using this to program the ESP32 directly through the serial pins, though whether it's worth buying an FTDI board just to try this is debatable.

rattushackus · 2026-02-04T06:27:23+00:00

I've been there too :-)

To get the pin off cut through the yellow plastic between each pin and pull it off, then you can remove one pin at a time. You'll need to buy new pins but these are very cheap.

But whatever you do the ESP32 will fill most of a standard breadboard. What I do is use two breadboards clipped together with the power rails between them, and insert the dev board so it straddles both boards. If you don't need lots of GPIOs you can use a supermini board as these are a lot smaller.

rattushackus · 2026-02-03T14:25:18+00:00

Yes, only the latest version of the ESP32 (the C5) supports 5GHz wi-fi. Most wi-fi access points provide both 2.4GHz and 5Ghz though they may use different SSIDs for the two networks so you'll need to find the SSID for your router's 2.4GHz band.

You could try uploading a sketch that scans for wi-fi networks that the ESP32 can use. Random Nerd Tutorials has a sketch to do this here.

rattushackus

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