RaspberryPi-bmp180 not providing output


I'm using node-red-contrib-brads-i2c-nodes to read temperature and pressure. I also have a python script that works successfully but wanted to try my hand at Node-Red.
I'm new to Node-Red but am frustrated.
Error is: 2/21/2019, 7:26:43 PMnode: 1cd94fa8.b7ae4
msg.payload : string[22] " unrecognized command."
node bmp180 "ready"
node bmp180 output: msg.payload.temperature
I don't know what to send to node bmp180 to read it from the inject node.
It seem that the upstream node are not configured correctly.
Any help would be appreciated.



If you click on the 1cd94fa8.b7ae4 bit in the debug it should highlight the node that is causing the error.

How have you configured the bmp180 node you are using?



bmp180: node imput: none
node output: 1. msg.payload.temperature
node output: 2 msg.payload.humidity
topic: temperature
node says "ready"
node function:
msg.payload = msg.payload;
return msg;
node debug:
input: msg.payload
output: msg.payload
i'm kicking off the project by injecting time (hoping is is not used).
1550845445544 unrecognized command. <--- timestamp?
node-red messages:
21 Feb 19:41:52 - [info] [bmp180:bmp180] {"id":"3d9c10af.110338","type":"bmp180","z":"f6294210.397ab8","name":"bmp180","topic":"temperature","presolution":244,"debugMode":true,"x":320,"y":220,"wires":[["ad5994d2.58464","1cd94fa8.b7ae4"],[]],"outputLabels":["msg.payload.temperature","msg.payload.humidity"]}
21 Feb 19:41:52 - [info] [bmp180:BMP180 @ 0x77] node.p_oversampling -> {"timeMs":26,"value":244,"oss":3,"samples":8}
21 Feb 19:41:52 - [info] Started flows
21 Feb 19:41:52 - [info] [bmp180:BMP180 @ 0x77]
bmp180 calibration parameters loaded.
Calibration Address: 0x8889 AC1 -> 0x1e6b (7787)
Calibration Address: 0x8a8b AC2 -> 0x-4ac (-1196)
Calibration Address: 0x8c8d AC3 -> 0x-3990 (-14736)
Calibration Address: 0x8e8f AC4 -> 0x830e (33550)
Calibration Address: 0x9091 AC5 -> 0x5e69 (24169)
Calibration Address: 0x9293 AC6 -> 0x4359 (17241)
Calibration Address: 0x9495 B1 -> 0x157a (5498)
Calibration Address: 0x9697 B2 -> 0x40 (64)
Calibration Address: 0x9899 MB -> 0x-8000 (-32768)
Calibration Address: 0x9a9b MC -> 0x-2b43 (-11075)
Calibration Address: 0x9c9d MD -> 0x980 (2432)
21 Feb 19:41:52 - [info] [bmp180:BMP180 @ 0x77] BMP180 @ 0x77 ready.
21 Feb 19:41:52 - [info] [bmp180:BMP180 @ 0x77] {"topic":"","payload":"1550796112167 unrecognized command.","_msgid":"5365c8bf.9b0268"}
21 Feb 19:41:52 - [info] [debug:1cd94fa8.b7ae4] 1550796112167 unrecognized command.
21 Feb 19:41:52 - [info] [debug:1cd94fa8.b7ae4] 1550796112167 unrecognized command.
node 1cd941a8.b7ae4 is a debug node

Hope this help.



Looking at the code for that node it seems you need to send it a string "measure" for it to reply correctly - change your inject to send that and see what happens.

From the overall project readme

All nodes use an [ inject ] node to send a string command of 'measure' to initiate sensor measurement based on values set in the config panels of the flow diagram.

But yeah - docs is not his thing... maybe worth raising an issue on the github page for that node to add something to the info for each node - but it's been a while since he touched it.



dceejay - You're right on. Where is this documented?
2/22/2019, 4:48:39 PMnode: 1cd94fa8.b7ae4bmp180 : msg.payload : Object


name: "BMP180 @ 0x77"

timestamp: "2/22/2019, 16:48:38"

Tc: "30.90"

Tf: "87.61"

p: "101814.90"

P: "30.07"

altm: "-40.71"

altf: "-12.41"

Thanks for your help



It's on the main project page for the node you mentioned



Ah, yes. I see it now.
Thank you again.
I have soo much to learn.