[Energia Library] Bosch BMP085 Template Library

[RobLewis 7]

Reflecting on this a bit more, I wonder if one of the later Energia updates somehow broke the I2C driver when the F5529 (and possibly other boards) is run at 16 MHz. 

 

And of course that 8-bit patch needs to be mainlined, eh? 

[bogdanvisan20 0]

Hi RobLewis,

 

I have the same problem, reading 0.0C and 2hPa.

Did you find any solution in the mean time?

[bogdanvisan20 0]

I tried it with Energia 0101E0010 and it works. But the DHT22 libraries don't work with this Eenergia version.

Does anyone know how to adapt it for the last Energia version?

[RobLewis 7]

Everything I know about this issue is contained in my previous posts, particularly those from last May 3. 

 

I don't know whether @@chicken might have any additional insights, or whether Energia has been patched to fix the apparent timing problem. 

[chicken 630]

I haven't played with this for a long time.

 

I see that there are several recent I2C related commits for Energia on Github, so maybe worth to clone the project and copying the hardware/msp430 tree into an Energia 16 tree.

 

Maybe I will spend this Sunday afternoon trying it myself.

[chicken 630]

@@RobLewis @@bogdanvisan20
 
Ok, I rewrote the I2C part of the library so that it properly uses beginTransmission and endTransmission() and it now seems to work with Energia 16 and the G2 launchpad.

 

I remember that I had to fudge with begin/endTransmission originally to work around oddities of the Energia I2C implementation. It looks like Energia is fixed now and my workarounds are broken.

 

Below the corrected bit of code (towards the bottom of BMP085_t.h). I will update it on GitHub shortly.

  // send command to BMP085
  void m_sendCmd(uint8_t cmd) {  
    Wire.beginTransmission(i2caddress);
    Wire.write(byte(BMP085_REG_CTRL));      
    Wire.write(byte(cmd));
    Wire.endTransmission();
  }
  
  // read 8 bits from I2C
  uint8_t m_read8(uint8_t addr) {
    uint8_t ret;

    Wire.beginTransmission(i2caddress);
    Wire.write(addr);
    Wire.endTransmission();

    Wire.beginTransmission(i2caddress);
    Wire.requestFrom(i2caddress, (uint8_t)1);    // need to cast int to avoid compiler warnings
    ret = Wire.read();
    Wire.endTransmission();
	
    return ret;
  };

  // read 16 bits from I2C
  uint16_t m_read16(uint8_t addr) {
    uint16_t ret;
	
    Wire.beginTransmission(i2caddress);
    Wire.write(addr);
    Wire.endTransmission();

    Wire.beginTransmission(i2caddress);
    Wire.requestFrom(i2caddress, (uint8_t)2);    // need to cast int to avoid compiler warnings
    ret = (Wire.read() << 8) | Wire.read();
    Wire.endTransmission();
	
    return ret;
  };

[RobLewis 7]

Very cool, thanks @@chicken! 

 

Do you have any idea whether this may restore the routine's ability to work at a 16MHz clock rate in the F5529? (I found that in later versions of Energia even the patched code would only work at 25 MHz). 

[Towhid 2]

hello ...i am very new to this world...i have to interface bosch bme280 with msp432 launchpad...i have done 12c interface and have been able to see the output in serial monitor of energia ...i have a sharp lcd boosterpack and have to show the sensor output there but dont know how ..can anyone help ??

[chicken 630]

@@Towhid you could try my Energia library for the same LCD

https://github.com/astuder/MSP430-sharp-LS013B4DN02-memory-display

[hyte 0]

1 Thanks for this library, very useful

2 I have been struggling for a long time to get this to work. I tried energia v17 and it wouldn't work but the cause wasn't obvious to me.  So i tried many things and wories I'd fried something.  Changing to energia v16 it worked immediately

 

I have an msp430g2553 with msp-exp430g2 rev1.3.  I have also removed c24 and r34 (I can't remember why) and have txd and rxd cross jumpered.  I am running a BMP85 chip that I've soldered myself with 5k pullups and decoupling cap.

 

Hope this helps someone

[chicken 630]

I haven't tried Energia 17 myself yet. I've read somewhere that I2C was moved to different pins, but not sure if that also applies to the G2553 LP.

[Martaet 0]

in my NSpace demos renders and fills polygons too, even in different states of flipping and rotation. Not sure how that library compares but it would be interesting to find out.

[denzel 0]

On 12/19/2015 at 2:58 PM, Towhid said:

hello ...i am very new to this world...i have to interface bosch bme280 with msp432 launchpad...i have done 12c interface and have been able to see the output in serial monitor of energia ...i have a sharp lcd boosterpack and have to show the sensor output there but dont know how ..can anyone help ??

Could you share the code for this?

[TranVinhPhuc 0]

Hello @chicken im using your Library with Energia 0101E0017 and it not work with MSP430G2253 . Cant you help me !!! 

[Rei Vilo 695]

See