BME280

[B2CAP-V6]

Thank you all,

Take a look at the copy of my schematic; it's wired exactly as you described, Bijumon (Thanks for your feedback)
Martin, you're right—I just measured the values ​​on the SDA line with the oscilloscope and got a peak signal of around 5V, whereas on the SCL line, the peak signal is only 200mV.
Tomorrow, I'll try to save the oscilloscope traces to a USB drive.
I don't have a USB-to-UART bridge or a logic analyzer.
However, there is some signal loss at times; I need to analyze that tomorrow—it's been a very difficult day today.
Thanks again for your replies.
Luc Bijumon, see my copy

[B2CAP-V6]

Hello everyone,
I have some good news: I rebuilt the circuit on a breadboard, and it works!
I’ll put together a report tomorrow—I’m just too tired tonight. I’ll also send over some photos of the measurements taken with my oscilloscope.
A huge thank you to everyone, and especially to Martin, who convinced me that this sensor ought to work—that was really important.
Thanks again, Martin, for your highly professional involvement.
Luc

[B2CAP-V6]

I’m getting back to you with some thoughts regarding the malfunction with the PCB.
In Flowcode, I did correctly configure the unused pins as inputs with an initial value of 0. However, on the PCB, I didn't physically set these pins to a pull-down state!
From experience, I know that the 18F series is very sensitive to this kind of oversight. I rushed the creation of this prototype PCB—I really messed up!
I’ve attached a few images. The readings from the PCB were unstable, whereas the ones from the breadboard are perfectly stable. My next step is to desolder the BME from the PCB and test it on the breadboard.
A huge thank you to everyone, and especially to Martin, who helped restore my confidence and got me up to speed with this BME sensor. Just for your information, Martin: I am indeed getting a return value of 1 during the BME initialization.
Luc

[chipfryer27]

Hi

However, on the PCB, I didn't physically set these pins to a pull-down state!

If the pins are indeed floating, with no connection to anything, you may be able to save by making your unused pins outputs set to 0.

Regards

[jgu1]

Hi Luc!

I know the frustration when something doesn’t work as expected, but also the joy when you finally get it working. I’d also like to contribute whenever I can.

I’ve received a great deal of help from the talented team and the Valued Contributors here on the forum, and I really appreciate it.

As an example, I have a Flowcode project using a BME280 and an Arduino and a I2cdisplay. I have build a small weather station. It transmits data wirelessly via an HC-12 module using an ESP32-S3. At the receiving end, I have another HC-12 connected to an ESP32-S2 with a display ST7796. The whole setup works perfectly.

If you’re interested, and there’s anything in the project that you might find useful or that could help you in some way, I’d be more than happy to share it here on the forum.

Br Jorgen

[medelec35]

Hi Luc.
Thank you for the nice words.
You're welcome and I'm glad you persevered and got BME280 to work.
Setting up the return value is always a go indication.

Hi Jorgen that does sound like a great project!
This would be an ideal location to add it for others to see.

[jgu1]

Of course, Martin, hereby.

My example using a BME280 and an Arduino Uno uses I²C. In this example, I used C0 and C1 for the BME280, so the communication speed is limited to 100 kHz, and C4 and C5 for the display.

I have also tried using CH1 with both components connected to the same bus, and that works perfectly too, at 500 kHz.

For the weather station project (BME280 only, no wind sensor), as mentioned earlier, I used a BME280 together with an ESP32-S3 Mini. It reads the data from the BME280 and transmits it wirelessly via an HC-12 module (UART) every five minutes.

At the receiving end, I use another HC-12 module. It passes the data to an ESP32-S2 Mini, which separates the different data values and displays them on an ILI9341 (not ST7796) SPI display. Everything works perfectly.

The HC-12 modules are small, inexpensive transceivers that can be configured for different baud rates, transmission power (up to 100 mW), and channels, covering frequencies from approximately 434 MHz up to 467 MHz, so there is plenty to experiment with.

They are very easy to configure, and there is an Arduino IDE example available that works well. Tom gives a good explanation of the configuration and provides examples here:

https://www.youtube.com/watch?v=DGRPqeacJns And lot of other examble on te web.

(It would be great if we had a similar AT-command configuration feature in Flowcode as well.)

Perhaps someone else here could find this project useful.

The most difficult part was filing out the hole for the display. I reused an enclosure from an old power supply. It’s a shame you can’t get drill bits that make square holes

Flowcode is a great tool

EDIT: @ martin, forgot the " this", are you able til move this?

Nice weekend Jorgen

[B2CAP-V6]

This forum is absolutely fantastic!
To give you a bit more detail: I’m retired, but I think I’m actually working harder now than I did during my professional career . I volunteer to help a friend who makes sausages, cured meats, and other charcuterie. He needs a system to measure and regulate both temperature and humidity. With the help of the BME sensor—and, of course, everyone here on the forum—I’ll be able to control heating elements (for temperature) and fans (to regulate humidity). I went from being an engineer in the automotive industry to becoming a farmer; I manage a forest and some crops (this year it was potatoes—the harvest was disastrous due to the weather, but that’s alright; the joy is in the cultivation itself). So, now you know pretty much everything about me—which explains why I wasn’t always around to reply or make adjustments.
Thanks again to everyone!
Luc