BME280 hardware SPI not working on Mega2560 (fixed)

[lloo]

Using the standard BME280 library i ran into a strange issue when trying to use the BME280 from a Mega2560.
Using the stadard library on a Nano the hardware SPI works OK.
Because the BME280 library is using more memory than average i switched to a Mega2560. Just replaced pins 10, 11, 12, 13 to the corresponding 53, 51, 50, 52.
Tried 2 Mega2560 boards. Both just no response at all.
Then switched from hardware SPI to software SPI:

BME280SpiSw::Settings settings(BME_PIN, BME_MOSI, BME_MISO, BME_SCK);
BME280SpiSw bme(settings);

This is working fine.

NO clue what the issue is. If you ran into the same issue then atleast you have a workaround .

PS. I did have a levelshifter between the 5V mega and the 3.3V BME280 spi sensor!

[Whandall]

There should be no reason to specify the SPI pins, besides CS.
You are running Software SPI on the hardware pins.

[lloo]

As you mention i started with the Hardware SPI specifiying only CS.

• On Nano this worked.
• On Mega it did not so i tried to specify the other pins too. After strugeling for a few days i thought lets give the Software SPI a try. Suppricinly this worked

And yes i do the Software SPI on the hardware pins. Just because these pins were allready connected.

Now you mention, i now tried the Software SPI on the Mega using 10, 11, 12, 13. Strangly this does NOT work
At least i have a working config now

[Koepel]

How many level shifters do you have ? For every SPI signal ?

There is nothing wrong with a software SPI. If it works, use it.

For the hardware SPI, the SS pin (53) must be set as output.
It is written near the bottom of this page: https://www.arduino.cc/en/reference/SPI

Using software SPI at pins 10,11,12,13 should work, assuming you have a "R3" version of the Mega board.
Perhaps something is not reliable yet. Can you show how the level shifters are wired ?
The level shifters for the I2C bus make the TTL signals weaker.

Can you start thinking about buying a 3.3V Arduino board ?

[lloo]

Now also the Hardware SPI works on the Mega.

Many thanks for the tip: I missed the SS pin (53) must be set as output part.

For level shifters i am using a cheap 4-Channel logic voltage level converter. Not sure if you see this as a I2C one. Now it is working i will try to use a resitor only level shifting.

Again many thanks,
Hope other can benefit from this. I spend a lot of time.

Added these lines to the setup:

digitalWrite(53, HIGH); 
pinMode(53, OUTPUT);
SPI.begin();

[lloo]

To compleet the interface from a 5v arduino to the 3.3v BME280.
I needed 3 level shifters to get it working:
The CLK signal did need an active one: 1 fet and 2 resistors.
For the CSB and MOSI a pasive of 2 resitors worked: 1k8 / 3k3 (18k / 33k did not work)
For the MISO no level shifters is needed.