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dgatf / msrc

Multi Sensor for RC with RP2040 - FrSky D, SmartPort, XBUS, SRXL, IBUS, SBUS, Multiplex Sensor Bus, Jeti Ex Bus, Hitec, CRSF
GNU General Public License v3.0
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Atmega2560 pins #22

Closed stefaanbolle closed 3 years ago

stefaanbolle commented 3 years ago

In your table I notice: ESC serial RX1 GPS RX2 PWM out 7 S.port/SRXL 4/12 XBUS/sensor SDA20 XBUS/sensor SCL21

What pins do you mean on a Mega2560 Pro Mini board because I do not find these pin references on my board https://pg-cdn-a2.datacaciques.com/00/NDAy/19/01/02/r4tvb3u808096tbn/ab2ddc6ef3b8ad95.jpg

stefaanbolle commented 3 years ago

Can this come into play http://www.varesano.net/blog/fabio/how-disable-internal-arduino-atmega-pullups-sda-and-scl-i2c-bus? The Mega2560 apparently outputs 5V on its I2C interface while the BMP280 is 3V3 only

stefaanbolle commented 3 years ago

If the case I probably blew up 2 BMP280-3V3 already :-) Have 2 BMP280-5V ordered now to test. Will arrive in 6 weeks or so :-p

dgatf commented 3 years ago

It might be. I always used a 3.3v BMP module without issues, but that does not guarantee other modules wont get burnt. Let me know

dgatf commented 3 years ago

As a last resort you can try with external pull up resistors (4~5k) on SDA and SCL lines. See circuit (Keep D20/D21 for I2C on your ATmega2560)

stefaanbolle commented 3 years ago

In the meantime tested the BMP280-3V3 with an Arduino Pro Mini 3V3 (SDA -> A4 and SCL -> A5). I2CScan gives no address. Probably both modules are dead. Will try with the 5V version as soon it arrives

stefaanbolle commented 3 years ago

Even with a new BMP280-5V I get no output on Tmp and Alt