Problem running on node 4.2.1 and debian Jessie

[teuteuguy]

When trying to the run a simple code I get stuck with it failing. Any ideas would be welcome.

So far this is my code

var i2c = require('i2c-bus');

var HTS221_ADDR = 0xBF; var CMD_TEMP_HIGH = 0x2B; var CMD_TEMP_LOW = 0x2A; var CMD_HUMID_HIGH = 0x29; var CMD_HUMID_LOW = 0x28;

module.exports.get = function(cb) {

var i2c1 = i2c.openSync(1);

var rawTemp = i2c1.readByteSync(HTS221_ADDR, CMD_TEMP_HIGH); console.log(rawTemp);

i2c1.closeSync();

};

---

i2c.setAddrSync(peripheral, addr); ^

Error: EINVAL, Invalid argument at Error (native) at peripheralSync (/home/pi/dev/node/node_modules/raspberry-sensor-sense-hat/node_modules/i2c-bus/i2c-bus.js:89:46) at Bus.readByteSync (/home/pi/dev/node/node_modules/raspberry-sensor-sense-hat/node_modules/i2c-bus/i2c-bus.js:162:27) at Object.module.exports.get (/home/pi/dev/node/node_modules/raspberry-sensor-sense-hat/index.js:13:22) at Object. (/home/pi/dev/node/app.js:8:7) at Module._compile (module.js:435:26) at Object.Module._extensions..js (module.js:442:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:311:12) at Function.Module.runMain (module.js:467:10)

[fivdi]

Please use the i2cdetect to determine whether or not there really is a device at address 0xbf and report your findings. This can be done with the following command:

i2cdetect -y -r 1

if it's not already installed, i2cdetect can be installed with sudo apt-get install i2c-tools (I think)

[teuteuguy]

Thanks for this great tool ! This is what I get from the response.

i2cdetect -y -r 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- 1c -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- UU -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- 5c -- -- 5f
60: -- -- -- -- -- -- -- -- -- -- 6a -- -- -- -- --
70: -- -- -- -- -- -- -- --

Basically I'm trying to interact with the sense-hat. Reading up on it, I got the 0xBF from the HTS221 humidity sensor.

From the spec: The 8-bit slave address (SAD) associated to the HTS221 humidity sensor is BEh (write) and BFh (read).

Google search of the SenseHat schematic brings this: https://www.raspberrypi.org/wp-content/uploads/2015/08/Sense-HAT-V1_0.pdf

For which there are at least 2 components I'm trying to communicate with over node. The humidity sensor, for which the datasheet says is the HTS221 and the Pressure sensor which points to the LPS25H, both (given their datasheets) at 0xBE/0xBF and 0x2E respectivelly.

None of these addresses come back from the i2cdetect function ... odd

[fivdi]

Although the documentation for the HTS221 speaks of 8-bit addresses, they really only have 7 bits. Bit 0 (the least significant bit) shouldn't be taken into account. The correct address in this case is probably 0x5f. Please try with address 0x5f to see if it works.

[teuteuguy]

OK, my bad. Sorry about that. Works perfect on 0x5f. I'll close the "issue". Cheers

[fivdi]

That's good news. Have fun with i2c-bus :)

[teuteuguy]

Thanks ! CHeers